×
Installing a cluster on VMC in a restricted network with user-provisioned infrastructure
- Setting up VMC for vSphere
- vSphere prerequisites
- About installations in restricted networks
- Internet access for OpenShift Container Platform
- VMware vSphere infrastructure requirements
- VMware vSphere CSI Driver Operator requirements
- Requirements for a cluster with user-provisioned infrastructure
- vCenter requirements
- Required machines for cluster installation
- Minimum resource requirements for cluster installation
- Certificate signing requests management
- Networking requirements for user-provisioned infrastructure
- User-provisioned DNS requirements
- Load balancing requirements for user-provisioned infrastructure
- Preparing the user-provisioned infrastructure
- Validating DNS resolution for user-provisioned infrastructure
- Generating a key pair for cluster node SSH access
- VMware vSphere region and zone enablement
- Manually creating the installation configuration file
- Creating the Kubernetes manifest and Ignition config files
- Extracting the infrastructure name
- Installing RHCOS and starting the OpenShift Container Platform bootstrap process
- Adding more compute machines to a cluster in vSphere
- Disk partitioning
- Waiting for the bootstrap process to complete
- Logging in to the cluster by using the CLI
- Approving the certificate signing requests for your machines
- Initial Operator configuration
- Completing installation on user-provisioned infrastructure
- Backing up VMware vSphere volumes
- Telemetry access for OpenShift Container Platform
- Next steps
In OpenShift Container Platform version 4.13, you can install a cluster on VMware vSphere infrastructure that you provision in a restricted network by deploying it to VMware Cloud (VMC) on AWS.
Once you configure your VMC environment for OpenShift Container Platform deployment, you use the OpenShift Container Platform installation program from the bastion management host, co-located in the VMC environment. The installation program and control plane automates the process of deploying and managing the resources needed for the OpenShift Container Platform cluster.
|
OpenShift Container Platform supports deploying a cluster to a single VMware vCenter only. Deploying a cluster with machines/machine sets on multiple vCenters is not supported. |
Setting up VMC for vSphere
You can install OpenShift Container Platform on VMware Cloud (VMC) on AWS hosted vSphere clusters to enable applications to be deployed and managed both on-premise and off-premise, across the hybrid cloud.
You must configure several options in your VMC environment prior to installing OpenShift Container Platform on VMware vSphere. Ensure your VMC environment has the following prerequisites:
-
Create a non-exclusive, DHCP-enabled, NSX-T network segment and subnet. Other virtual machines (VMs) can be hosted on the subnet, but at least eight IP addresses must be available for the OpenShift Container Platform deployment.
-
Configure the following firewall rules:
-
An ANY:ANY firewall rule between the installation host and the software-defined data center (SDDC) management network on port 443. This allows you to upload the Red Hat Enterprise Linux CoreOS (RHCOS) OVA during deployment.
-
An HTTPS firewall rule between the OpenShift Container Platform compute network and vCenter. This connection allows OpenShift Container Platform to communicate with vCenter for provisioning and managing nodes, persistent volume claims (PVCs), and other resources.
-
-
You must have the following information to deploy OpenShift Container Platform:
-
The OpenShift Container Platform cluster name, such as
vmc-prod-1. -
The base DNS name, such as
companyname.com. -
If not using the default, the pod network CIDR and services network CIDR must be identified, which are set by default to
10.128.0.0/14and172.30.0.0/16, respectively. These CIDRs are used for pod-to-pod and pod-to-service communication and are not accessible externally; however, they must not overlap with existing subnets in your organization. -
The following vCenter information:
-
vCenter hostname, username, and password
-
Datacenter name, such as
SDDC-Datacenter -
Cluster name, such as
Cluster-1 -
Network name
-
Datastore name, such as
WorkloadDatastoreIt is recommended to move your vSphere cluster to the VMC
Compute-ResourcePoolresource pool after your cluster installation is finished.
-
-
-
A Linux-based host deployed to VMC as a bastion.
-
The bastion host can be Red Hat Enterprise Linux (RHEL) or any another Linux-based host; it must have internet connectivity and the ability to upload an OVA to the ESXi hosts.
-
Download and install the OpenShift CLI tools to the bastion host.
-
The
openshift-installinstallation program -
The OpenShift CLI (
oc) tool
-
-
|
You cannot use the VMware NSX Container Plugin for Kubernetes (NCP), and NSX is not used as the OpenShift SDN. The version of NSX currently available with VMC is incompatible with the version of NCP certified with OpenShift Container Platform. However, the NSX DHCP service is used for virtual machine IP management with the full-stack automated OpenShift Container Platform deployment and with nodes provisioned, either manually or automatically, by the Machine API integration with vSphere. Additionally, NSX firewall rules are created to enable access with the OpenShift Container Platform cluster and between the bastion host and the VMC vSphere hosts. |
VMC Sizer tool
VMware Cloud on AWS is built on top of AWS bare metal infrastructure; this is the same bare metal infrastructure which runs AWS native services. When a VMware cloud on AWS software-defined data center (SDDC) is deployed, you consume these physical server nodes and run the VMware ESXi hypervisor in a single tenant fashion. This means the physical infrastructure is not accessible to anyone else using VMC. It is important to consider how many physical hosts you will need to host your virtual infrastructure.
To determine this, VMware provides the VMC on AWS Sizer. With this tool, you can define the resources you intend to host on VMC:
-
Types of workloads
-
Total number of virtual machines
-
Specification information such as:
-
Storage requirements
-
vCPUs
-
vRAM
-
Overcommit ratios
-
With these details, the sizer tool can generate a report, based on VMware best practices, and recommend your cluster configuration and the number of hosts you will need.
vSphere prerequisites
-
You reviewed details about the OpenShift Container Platform installation and update processes.
-
You read the documentation on selecting a cluster installation method and preparing it for users.
-
You created a registry on your mirror host and obtain the
imageContentSourcesdata for your version of OpenShift Container Platform.Because the installation media is on the mirror host, you can use that computer to complete all installation steps.
-
You provisioned block registry storage. For more information on persistent storage, see Understanding persistent storage.
-
If you use a firewall and plan to use the Telemetry service, you configured the firewall to allow the sites that your cluster requires access to.
Be sure to also review this site list if you are configuring a proxy.
About installations in restricted networks
In OpenShift Container Platform 4.13, you can perform an installation that does not require an active connection to the internet to obtain software components. Restricted network installations can be completed using installer-provisioned infrastructure or user-provisioned infrastructure, depending on the cloud platform to which you are installing the cluster.
If you choose to perform a restricted network installation on a cloud platform, you still require access to its cloud APIs. Some cloud functions, like Amazon Web Service’s Route 53 DNS and IAM services, require internet access. Depending on your network, you might require less internet access for an installation on bare metal hardware, Nutanix, or on VMware vSphere.
To complete a restricted network installation, you must create a registry that mirrors the contents of the OpenShift image registry and contains the installation media. You can create this registry on a mirror host, which can access both the internet and your closed network, or by using other methods that meet your restrictions.
|
Because of the complexity of the configuration for user-provisioned installations, consider completing a standard user-provisioned infrastructure installation before you attempt a restricted network installation using user-provisioned infrastructure. Completing this test installation might make it easier to isolate and troubleshoot any issues that might arise during your installation in a restricted network. |
Additional limits
Clusters in restricted networks have the following additional limitations and restrictions:
-
The
ClusterVersionstatus includes anUnable to retrieve available updateserror. -
By default, you cannot use the contents of the Developer Catalog because you cannot access the required image stream tags.
Internet access for OpenShift Container Platform
In OpenShift Container Platform 4.13, you require access to the internet to obtain the images that are necessary to install your cluster.
You must have internet access to:
-
Access OpenShift Cluster Manager Hybrid Cloud Console to download the installation program and perform subscription management. If the cluster has internet access and you do not disable Telemetry, that service automatically entitles your cluster.
-
Access Quay.io to obtain the packages that are required to install your cluster.
-
Obtain the packages that are required to perform cluster updates.
VMware vSphere infrastructure requirements
You must install an OpenShift Container Platform cluster on one of the following versions of a VMware vSphere instance that meets the requirements for the components that you use:
-
Version 7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later
-
Version 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later
You can host the VMware vSphere infrastructure on-premise or on a VMware Cloud Verified provider that meets the requirements outlined in the following table:
| Virtual environment product | Required version |
|---|---|
VMware virtual hardware |
15 or later |
vSphere ESXi hosts |
7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later; 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later |
vCenter host |
7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later; 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later |
| Component | Minimum supported versions | Description |
|---|---|---|
Hypervisor |
vSphere 7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later; vSphere 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later with virtual hardware version 15 |
This hypervisor version is the minimum version that Red Hat Enterprise Linux CoreOS (RHCOS) supports. For more information about supported hardware on the latest version of Red Hat Enterprise Linux (RHEL) that is compatible with RHCOS, see Hardware on the Red Hat Customer Portal. |
Storage with in-tree drivers |
vSphere 7.0 Update 2 and later; 8.0 Update 1 or later |
This plugin creates vSphere storage by using the in-tree storage drivers for vSphere included in OpenShift Container Platform. |
CPU micro-architecture |
x86-64-v2 or higher |
OpenShift 4.13 and later are based on RHEL 9.2 host operating system which raised the microarchitecture requirements to x86-64-v2. See the RHEL Microarchitecture requirements documentation. You can verify compatibility by following the procedures outlined in this KCS article. |
|
You must ensure that the time on your ESXi hosts is synchronized before you install OpenShift Container Platform. See Edit Time Configuration for a Host in the VMware documentation. |
Additional resources
-
For more information about CSI automatic migration, see "Overview" in VMware vSphere CSI Driver Operator.
VMware vSphere CSI Driver Operator requirements
To install the vSphere CSI Driver Operator, the following requirements must be met:
-
VMware vSphere version: 7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later; 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later
-
vCenter version: 7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later; 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later
-
Virtual machines of hardware version 15 or later
-
No third-party vSphere CSI driver already installed in the cluster
If a third-party vSphere CSI driver is present in the cluster, OpenShift Container Platform does not overwrite it. The presence of a third-party vSphere CSI driver prevents OpenShift Container Platform from updating to OpenShift Container Platform 4.13 or later.
|
The VMware vSphere CSI Driver Operator is supported only on clusters deployed with |
Additional resources
-
To remove a third-party CSI driver, see Removing a third-party vSphere CSI Driver.
-
To update the hardware version for your vSphere nodes, see Updating hardware on nodes running in vSphere.
Requirements for a cluster with user-provisioned infrastructure
For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.
This section describes the requirements for deploying OpenShift Container Platform on user-provisioned infrastructure.
vCenter requirements
Before you install an OpenShift Container Platform cluster on your vCenter that uses infrastructure that you provided, you must prepare your environment.
Required vCenter account privileges
To install an OpenShift Container Platform cluster in a vCenter, your vSphere account must include privileges for reading and creating the required resources. Using an account that has global administrative privileges is the simplest way to access all of the necessary permissions.
Roles and privileges required for installation in vSphere API
| vSphere object for role | When required | Required privileges in vSphere API |
|---|---|---|
vSphere vCenter |
Always |
|
vSphere vCenter Cluster |
If VMs will be created in the cluster root |
|
vSphere vCenter Resource Pool |
If an existing resource pool is provided |
|
vSphere Datastore |
Always |
|
vSphere Port Group |
Always |
|
Virtual Machine Folder |
Always |
|
vSphere vCenter Datacenter |
If the installation program creates the virtual machine folder. For UPI, |
|
Roles and privileges required for installation in vCenter graphical user interface (GUI)
| vSphere object for role | When required | Required privileges in vCenter GUI |
|---|---|---|
vSphere vCenter |
Always |
|
vSphere vCenter Cluster |
If VMs will be created in the cluster root |
|
vSphere vCenter Resource Pool |
If an existing resource pool is provided |
|
vSphere Datastore |
Always |
|
vSphere Port Group |
Always |
|
Virtual Machine Folder |
Always |
|
vSphere vCenter Datacenter |
If the installation program creates the virtual machine folder. For UPI, |
|
Additionally, the user requires some ReadOnly permissions, and some of the roles require permission to propogate the permissions to child objects. These settings vary depending on whether or not you install the cluster into an existing folder.
Required permissions and propagation settings
| vSphere object | When required | Propagate to children | Permissions required |
|---|---|---|---|
vSphere vCenter |
Always |
False |
Listed required privileges |
vSphere vCenter Datacenter |
Existing folder |
False |
|
Installation program creates the folder |
True |
Listed required privileges |
|
vSphere vCenter Cluster |
Existing resource pool |
False |
|
VMs in cluster root |
True |
Listed required privileges |
|
vSphere vCenter Datastore |
Always |
False |
Listed required privileges |
vSphere Switch |
Always |
False |
|
vSphere Port Group |
Always |
False |
Listed required privileges |
vSphere vCenter Virtual Machine Folder |
Existing folder |
True |
Listed required privileges |
vSphere vCenter Resource Pool |
Existing resource pool |
True |
Listed required privileges |
For more information about creating an account with only the required privileges, see vSphere Permissions and User Management Tasks in the vSphere documentation.
Using OpenShift Container Platform with vMotion
If you intend on using vMotion in your vSphere environment, consider the following before installing an OpenShift Container Platform cluster.
-
Using Storage vMotion can cause issues and is not supported.
-
Using VMware compute vMotion to migrate the workloads for both OpenShift Container Platform compute machines and control plane machines is generally supported, where generally implies that you meet all VMware best practices for vMotion.
To help ensure the uptime of your compute and control plane nodes, ensure that you follow the VMware best practices for vMotion, and use VMware anti-affinity rules to improve the availability of OpenShift Container Platform during maintenance or hardware issues.
For more information about vMotion and anti-affinity rules, see the VMware vSphere documentation for vMotion networking requirements and VM anti-affinity rules.
-
If you are using VMware vSphere volumes in your pods, migrating a VM across datastores, either manually or through Storage vMotion, causes invalid references within OpenShift Container Platform persistent volume (PV) objects that can result in data loss.
-
OpenShift Container Platform does not support selective migration of VMDKs across datastores, using datastore clusters for VM provisioning or for dynamic or static provisioning of PVs, or using a datastore that is part of a datastore cluster for dynamic or static provisioning of PVs.
Cluster resources
When you deploy an OpenShift Container Platform cluster that uses infrastructure that you provided, you must create the following resources in your vCenter instance:
-
1 Folder
-
1 Tag category
-
1 Tag
-
Virtual machines:
-
1 template
-
1 temporary bootstrap node
-
3 control plane nodes
-
3 compute machines
-
Although these resources use 856 GB of storage, the bootstrap node is destroyed during the cluster installation process. A minimum of 800 GB of storage is required to use a standard cluster.
If you deploy more compute machines, the OpenShift Container Platform cluster will use more storage.
Cluster limits
Available resources vary between clusters. The number of possible clusters within a vCenter is limited primarily by available storage space and any limitations on the number of required resources. Be sure to consider both limitations to the vCenter resources that the cluster creates and the resources that you require to deploy a cluster, such as IP addresses and networks.
Networking requirements
You can use Dynamic Host Configuration Protocol (DHCP) for the network and configure the DHCP server to set persistent IP addresses to machines in your cluster. In the DHCP lease, you must configure the DHCP to use the default gateway.
|
You do not need to use the DHCP for the network if you want to provision nodes with static IP addresses. |
If you are installing to a restricted environment, the VM in your restricted network must have access to vCenter so that it can provision and manage nodes, persistent volume claims (PVCs), and other resources.
|
Ensure that each OpenShift Container Platform node in the cluster has access to a Network Time Protocol (NTP) server that is discoverable by DHCP. Installation is possible without an NTP server. However, asynchronous server clocks can cause errors, which the NTP server prevents. |
Additionally, you must create the following networking resources before you install the OpenShift Container Platform cluster:
Required IP Addresses
DNS records
You must create DNS records for two static IP addresses in the appropriate DNS server for the vCenter instance that hosts your OpenShift Container Platform cluster. In each record, <cluster_name> is the cluster name and <base_domain> is the cluster base domain that you specify when you install the cluster. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..
| Component | Record | Description |
|---|---|---|
API VIP |
|
This DNS A/AAAA or CNAME record must point to the load balancer for the control plane machines. This record must be resolvable by both clients external to the cluster and from all the nodes within the cluster. |
Ingress VIP |
|
A wildcard DNS A/AAAA or CNAME record that points to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. This record must be resolvable by both clients external to the cluster and from all the nodes within the cluster. |
Additional resources
Required machines for cluster installation
The smallest OpenShift Container Platform clusters require the following hosts:
| Hosts | Description |
|---|---|
One temporary bootstrap machine |
The cluster requires the bootstrap machine to deploy the OpenShift Container Platform cluster on the three control plane machines. You can remove the bootstrap machine after you install the cluster. |
Three control plane machines |
The control plane machines run the Kubernetes and OpenShift Container Platform services that form the control plane. |
At least two compute machines, which are also known as worker machines. |
The workloads requested by OpenShift Container Platform users run on the compute machines. |
|
To maintain high availability of your cluster, use separate physical hosts for these cluster machines. |
The bootstrap and control plane machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system. However, the compute machines can choose between Red Hat Enterprise Linux CoreOS (RHCOS), Red Hat Enterprise Linux (RHEL) 8.6 and later.
Note that RHCOS is based on Red Hat Enterprise Linux (RHEL) 9.2 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.
Minimum resource requirements for cluster installation
Each cluster machine must meet the following minimum requirements:
| Machine | Operating System | vCPU [1] | Virtual RAM | Storage | Input/Output Per Second (IOPS)[2] |
|---|---|---|---|---|---|
Bootstrap |
RHCOS |
4 |
16 GB |
100 GB |
300 |
Control plane |
RHCOS |
4 |
16 GB |
100 GB |
300 |
Compute |
RHCOS, RHEL 8.6 and later [3] |
2 |
8 GB |
100 GB |
300 |
-
One vCPU is equivalent to one physical core when simultaneous multithreading (SMT), or Hyper-Threading, is not enabled. When enabled, use the following formula to calculate the corresponding ratio: (threads per core × cores) × sockets = vCPUs.
-
OpenShift Container Platform and Kubernetes are sensitive to disk performance, and faster storage is recommended, particularly for etcd on the control plane nodes which require a 10 ms p99 fsync duration. Note that on many cloud platforms, storage size and IOPS scale together, so you might need to over-allocate storage volume to obtain sufficient performance.
-
As with all user-provisioned installations, if you choose to use RHEL compute machines in your cluster, you take responsibility for all operating system life cycle management and maintenance, including performing system updates, applying patches, and completing all other required tasks. Use of RHEL 7 compute machines is deprecated and has been removed in OpenShift Container Platform 4.10 and later.
|
As of OpenShift Container Platform version 4.13, RHCOS is based on RHEL version 9.2, which updates the micro-architecture requirements. The following list contains the minimum instruction set architectures (ISA) that each architecture requires:
For more information, see RHEL Architectures. |
If an instance type for your platform meets the minimum requirements for cluster machines, it is supported to use in OpenShift Container Platform.
Certificate signing requests management
Because your cluster has limited access to automatic machine management when you use infrastructure that you provision, you must provide a mechanism for approving cluster certificate signing requests (CSRs) after installation. The kube-controller-manager only approves the kubelet client CSRs. The machine-approver cannot guarantee the validity of a serving certificate that is requested by using kubelet credentials because it cannot confirm that the correct machine issued the request. You must determine and implement a method of verifying the validity of the kubelet serving certificate requests and approving them.
Networking requirements for user-provisioned infrastructure
All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require networking to be configured in initramfs during boot
to fetch their Ignition config files.
During the initial boot, the machines require an IP address configuration that is set either through a DHCP server or statically by providing the required boot options. After a network connection is established, the machines download their Ignition config files from an HTTP or HTTPS server. The Ignition config files are then used to set the exact state of each machine. The Machine Config Operator completes more changes to the machines, such as the application of new certificates or keys, after installation.
It is recommended to use a DHCP server for long-term management of the cluster machines. Ensure that the DHCP server is configured to provide persistent IP addresses, DNS server information, and hostnames to the cluster machines.
|
If a DHCP service is not available for your user-provisioned infrastructure, you can instead provide the IP networking configuration and the address of the DNS server to the nodes at RHCOS install time. These can be passed as boot arguments if you are installing from an ISO image. See the Installing RHCOS and starting the OpenShift Container Platform bootstrap process section for more information about static IP provisioning and advanced networking options. |
The Kubernetes API server must be able to resolve the node names of the cluster machines. If the API servers and worker nodes are in different zones, you can configure a default DNS search zone to allow the API server to resolve the node names. Another supported approach is to always refer to hosts by their fully-qualified domain names in both the node objects and all DNS requests.
Setting the cluster node hostnames through DHCP
On Red Hat Enterprise Linux CoreOS (RHCOS) machines, the hostname is set through NetworkManager. By default, the machines obtain their hostname through DHCP. If the hostname is not provided by DHCP, set statically through kernel arguments, or another method, it is obtained through a reverse DNS lookup. Reverse DNS lookup occurs after the network has been initialized on a node and can take time to resolve. Other system services can start prior to this and detect the hostname as localhost or similar. You can avoid this by using DHCP to provide the hostname for each cluster node.
Additionally, setting the hostnames through DHCP can bypass any manual DNS record name configuration errors in environments that have a DNS split-horizon implementation.
Network connectivity requirements
You must configure the network connectivity between machines to allow OpenShift Container Platform cluster components to communicate. Each machine must be able to resolve the hostnames of all other machines in the cluster.
This section provides details about the ports that are required.
|
In connected OpenShift Container Platform environments, all nodes are required to have internet access to pull images for platform containers and provide telemetry data to Red Hat. |
| Protocol | Port | Description |
|---|---|---|
ICMP |
N/A |
Network reachability tests |
TCP |
|
Metrics |
|
Host level services, including the node exporter on ports |
|
|
The default ports that Kubernetes reserves |
|
|
openshift-sdn |
|
UDP |
|
VXLAN |
|
Geneve |
|
|
Host level services, including the node exporter on ports |
|
|
IPsec IKE packets |
|
|
IPsec NAT-T packets |
|
|
Network Time Protocol (NTP) on UDP port If an external NTP time server is configured, you must open UDP port |
|
TCP/UDP |
|
Kubernetes node port |
ESP |
N/A |
IPsec Encapsulating Security Payload (ESP) |
| Protocol | Port | Description |
|---|---|---|
TCP |
|
Kubernetes API |
| Protocol | Port | Description |
|---|---|---|
TCP |
|
etcd server and peer ports |
Ethernet adaptor hardware address requirements
When provisioning VMs for the cluster, the ethernet interfaces configured for each VM must use a MAC address from the VMware Organizationally Unique Identifier (OUI) allocation ranges:
-
00:05:69:00:00:00to00:05:69:FF:FF:FF -
00:0c:29:00:00:00to00:0c:29:FF:FF:FF -
00:1c:14:00:00:00to00:1c:14:FF:FF:FF -
00:50:56:00:00:00to00:50:56:3F:FF:FF
If a MAC address outside the VMware OUI is used, the cluster installation will not succeed.
NTP configuration for user-provisioned infrastructure
OpenShift Container Platform clusters are configured to use a public Network Time Protocol (NTP) server by default. If you want to use a local enterprise NTP server, or if your cluster is being deployed in a disconnected network, you can configure the cluster to use a specific time server. For more information, see the documentation for Configuring chrony time service.
If a DHCP server provides NTP server information, the chrony time service on the Red Hat Enterprise Linux CoreOS (RHCOS) machines read the information and can sync the clock with the NTP servers.
User-provisioned DNS requirements
In OpenShift Container Platform deployments, DNS name resolution is required for the following components:
-
The Kubernetes API
-
The OpenShift Container Platform application wildcard
-
The bootstrap, control plane, and compute machines
Reverse DNS resolution is also required for the Kubernetes API, the bootstrap machine, the control plane machines, and the compute machines.
DNS A/AAAA or CNAME records are used for name resolution and PTR records are used for reverse name resolution. The reverse records are important because Red Hat Enterprise Linux CoreOS (RHCOS) uses the reverse records to set the hostnames for all the nodes, unless the hostnames are provided by DHCP. Additionally, the reverse records are used to generate the certificate signing requests (CSR) that OpenShift Container Platform needs to operate.
|
It is recommended to use a DHCP server to provide the hostnames to each cluster node. See the DHCP recommendations for user-provisioned infrastructure section for more information. |
The following DNS records are required for a user-provisioned OpenShift Container Platform cluster and they must be in place before installation. In each record, <cluster_name> is the cluster name and <base_domain> is the base domain that you specify in the install-config.yaml file. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..
| Component | Record | Description | |
|---|---|---|---|
Kubernetes API |
|
A DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the API load balancer. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster. |
|
|
A DNS A/AAAA or CNAME record, and a DNS PTR record, to internally identify the API load balancer. These records must be resolvable from all the nodes within the cluster.
|
||
Routes |
|
A wildcard DNS A/AAAA or CNAME record that refers to the application ingress load balancer. The application ingress load balancer targets the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster. For example, |
|
Bootstrap machine |
|
A DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the bootstrap machine. These records must be resolvable by the nodes within the cluster. |
|
Control plane machines |
|
DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the control plane nodes. These records must be resolvable by the nodes within the cluster. |
|
Compute machines |
|
DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the worker nodes. These records must be resolvable by the nodes within the cluster. |
|
In OpenShift Container Platform 4.4 and later, you do not need to specify etcd host and SRV records in your DNS configuration. |
|
You can use the |
Example DNS configuration for user-provisioned clusters
This section provides A and PTR record configuration samples that meet the DNS requirements for deploying OpenShift Container Platform on user-provisioned infrastructure. The samples are not meant to provide advice for choosing one DNS solution over another.
In the examples, the cluster name is ocp4 and the base domain is example.com.
Example DNS A record configuration for a user-provisioned cluster
The following example is a BIND zone file that shows sample A records for name resolution in a user-provisioned cluster.
Sample DNS zone database
$TTL 1W
@ IN SOA ns1.example.com. root (
2019070700 ; serial
3H ; refresh (3 hours)
30M ; retry (30 minutes)
2W ; expiry (2 weeks)
1W ) ; minimum (1 week)
IN NS ns1.example.com.
IN MX 10 smtp.example.com.
;
;
ns1.example.com. IN A 192.168.1.5
smtp.example.com. IN A 192.168.1.5
;
helper.example.com. IN A 192.168.1.5
helper.ocp4.example.com. IN A 192.168.1.5
;
api.ocp4.example.com. IN A 192.168.1.5 (1)
api-int.ocp4.example.com. IN A 192.168.1.5 (2)
;
*.apps.ocp4.example.com. IN A 192.168.1.5 (3)
;
bootstrap.ocp4.example.com. IN A 192.168.1.96 (4)
;
control-plane0.ocp4.example.com. IN A 192.168.1.97 (5)
control-plane1.ocp4.example.com. IN A 192.168.1.98 (5)
control-plane2.ocp4.example.com. IN A 192.168.1.99 (5)
;
compute0.ocp4.example.com. IN A 192.168.1.11 (6)
compute1.ocp4.example.com. IN A 192.168.1.7 (6)
;
;EOF| 1 | Provides name resolution for the Kubernetes API. The record refers to the IP address of the API load balancer. | ||
| 2 | Provides name resolution for the Kubernetes API. The record refers to the IP address of the API load balancer and is used for internal cluster communications. | ||
| 3 | Provides name resolution for the wildcard routes. The record refers to the IP address of the application ingress load balancer. The application ingress load balancer targets the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.
|
||
| 4 | Provides name resolution for the bootstrap machine. | ||
| 5 | Provides name resolution for the control plane machines. | ||
| 6 | Provides name resolution for the compute machines. |
Example DNS PTR record configuration for a user-provisioned cluster
The following example BIND zone file shows sample PTR records for reverse name resolution in a user-provisioned cluster.
Sample DNS zone database for reverse records
$TTL 1W
@ IN SOA ns1.example.com. root (
2019070700 ; serial
3H ; refresh (3 hours)
30M ; retry (30 minutes)
2W ; expiry (2 weeks)
1W ) ; minimum (1 week)
IN NS ns1.example.com.
;
5.1.168.192.in-addr.arpa. IN PTR api.ocp4.example.com. (1)
5.1.168.192.in-addr.arpa. IN PTR api-int.ocp4.example.com. (2)
;
96.1.168.192.in-addr.arpa. IN PTR bootstrap.ocp4.example.com. (3)
;
97.1.168.192.in-addr.arpa. IN PTR control-plane0.ocp4.example.com. (4)
98.1.168.192.in-addr.arpa. IN PTR control-plane1.ocp4.example.com. (4)
99.1.168.192.in-addr.arpa. IN PTR control-plane2.ocp4.example.com. (4)
;
11.1.168.192.in-addr.arpa. IN PTR compute0.ocp4.example.com. (5)
7.1.168.192.in-addr.arpa. IN PTR compute1.ocp4.example.com. (5)
;
;EOF| 1 | Provides reverse DNS resolution for the Kubernetes API. The PTR record refers to the record name of the API load balancer. |
| 2 | Provides reverse DNS resolution for the Kubernetes API. The PTR record refers to the record name of the API load balancer and is used for internal cluster communications. |
| 3 | Provides reverse DNS resolution for the bootstrap machine. |
| 4 | Provides reverse DNS resolution for the control plane machines. |
| 5 | Provides reverse DNS resolution for the compute machines. |
|
A PTR record is not required for the OpenShift Container Platform application wildcard. |
Load balancing requirements for user-provisioned infrastructure
Before you install OpenShift Container Platform, you must provision the API and application Ingress load balancing infrastructure. In production scenarios, you can deploy the API and application Ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.
|
If you want to deploy the API and application Ingress load balancers with a Red Hat Enterprise Linux (RHEL) instance, you must purchase the RHEL subscription separately. |
The load balancing infrastructure must meet the following requirements:
-
API load balancer: Provides a common endpoint for users, both human and machine, to interact with and configure the platform. Configure the following conditions:
-
Layer 4 load balancing only. This can be referred to as Raw TCP or SSL Passthrough mode.
-
A stateless load balancing algorithm. The options vary based on the load balancer implementation.
Do not configure session persistence for an API load balancer. Configuring session persistence for a Kubernetes API server might cause performance issues from excess application traffic for your OpenShift Container Platform cluster and the Kubernetes API that runs inside the cluster.
Configure the following ports on both the front and back of the load balancers:
Table 10. API load balancer Port Back-end machines (pool members) Internal External Description 6443Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane. You must configure the
/readyzendpoint for the API server health check probe.X
X
Kubernetes API server
22623Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane.
X
Machine config server
The load balancer must be configured to take a maximum of 30 seconds from the time the API server turns off the
/readyzendpoint to the removal of the API server instance from the pool. Within the time frame after/readyzreturns an error or becomes healthy, the endpoint must have been removed or added. Probing every 5 or 10 seconds, with two successful requests to become healthy and three to become unhealthy, are well-tested values. -
-
Application Ingress load balancer: Provides an ingress point for application traffic flowing in from outside the cluster. A working configuration for the Ingress router is required for an OpenShift Container Platform cluster.
Configure the following conditions:
-
Layer 4 load balancing only. This can be referred to as Raw TCP or SSL Passthrough mode.
-
A connection-based or session-based persistence is recommended, based on the options available and types of applications that will be hosted on the platform.
If the true IP address of the client can be seen by the application Ingress load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption.
Configure the following ports on both the front and back of the load balancers:
Table 11. Application Ingress load balancer Port Back-end machines (pool members) Internal External Description 443The machines that run the Ingress Controller pods, compute, or worker, by default.
X
X
HTTPS traffic
80The machines that run the Ingress Controller pods, compute, or worker, by default.
X
X
HTTP traffic
If you are deploying a three-node cluster with zero compute nodes, the Ingress Controller pods run on the control plane nodes. In three-node cluster deployments, you must configure your application Ingress load balancer to route HTTP and HTTPS traffic to the control plane nodes.
-
Example load balancer configuration for user-provisioned clusters
This section provides an example API and application Ingress load balancer configuration that meets the load balancing requirements for user-provisioned clusters. The sample is an /etc/haproxy/haproxy.cfg configuration for an HAProxy load balancer. The example is not meant to provide advice for choosing one load balancing solution over another.
In the example, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.
|
If you are using HAProxy as a load balancer and SELinux is set to |
Sample API and application Ingress load balancer configuration
global
log 127.0.0.1 local2
pidfile /var/run/haproxy.pid
maxconn 4000
daemon
defaults
mode http
log global
option dontlognull
option http-server-close
option redispatch
retries 3
timeout http-request 10s
timeout queue 1m
timeout connect 10s
timeout client 1m
timeout server 1m
timeout http-keep-alive 10s
timeout check 10s
maxconn 3000
listen api-server-6443 (1)
bind *:6443
mode tcp
option httpchk GET /readyz HTTP/1.0
option log-health-checks
balance roundrobin
server bootstrap bootstrap.ocp4.example.com:6443 verify none check check-ssl inter 10s fall 2 rise 3 backup (2)
server master0 master0.ocp4.example.com:6443 weight 1 verify none check check-ssl inter 10s fall 2 rise 3
server master1 master1.ocp4.example.com:6443 weight 1 verify none check check-ssl inter 10s fall 2 rise 3
server master2 master2.ocp4.example.com:6443 weight 1 verify none check check-ssl inter 10s fall 2 rise 3
listen machine-config-server-22623 (3)
bind *:22623
mode tcp
server bootstrap bootstrap.ocp4.example.com:22623 check inter 1s backup (2)
server master0 master0.ocp4.example.com:22623 check inter 1s
server master1 master1.ocp4.example.com:22623 check inter 1s
server master2 master2.ocp4.example.com:22623 check inter 1s
listen ingress-router-443 (4)
bind *:443
mode tcp
balance source
server worker0 worker0.ocp4.example.com:443 check inter 1s
server worker1 worker1.ocp4.example.com:443 check inter 1s
listen ingress-router-80 (5)
bind *:80
mode tcp
balance source
server worker0 worker0.ocp4.example.com:80 check inter 1s
server worker1 worker1.ocp4.example.com:80 check inter 1s| 1 | Port 6443 handles the Kubernetes API traffic and points to the control plane machines. |
||
| 2 | The bootstrap entries must be in place before the OpenShift Container Platform cluster installation and they must be removed after the bootstrap process is complete. | ||
| 3 | Port 22623 handles the machine config server traffic and points to the control plane machines. |
||
| 4 | Port 443 handles the HTTPS traffic and points to the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default. |
||
| 5 | Port 80 handles the HTTP traffic and points to the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.
|
|
If you are using HAProxy as a load balancer, you can check that the |
Preparing the user-provisioned infrastructure
Before you install OpenShift Container Platform on user-provisioned infrastructure, you must prepare the underlying infrastructure.
This section provides details about the high-level steps required to set up your cluster infrastructure in preparation for an OpenShift Container Platform installation. This includes configuring IP networking and network connectivity for your cluster nodes, enabling the required ports through your firewall, and setting up the required DNS and load balancing infrastructure.
After preparation, your cluster infrastructure must meet the requirements outlined in the Requirements for a cluster with user-provisioned infrastructure section.
Prerequisites
-
You have reviewed the OpenShift Container Platform 4.x Tested Integrations page.
-
You have reviewed the infrastructure requirements detailed in the Requirements for a cluster with user-provisioned infrastructure section.
Procedure
-
If you are using DHCP to provide the IP networking configuration to your cluster nodes, configure your DHCP service.
-
Add persistent IP addresses for the nodes to your DHCP server configuration. In your configuration, match the MAC address of the relevant network interface to the intended IP address for each node.
-
When you use DHCP to configure IP addressing for the cluster machines, the machines also obtain the DNS server information through DHCP. Define the persistent DNS server address that is used by the cluster nodes through your DHCP server configuration.
If you are not using a DHCP service, you must provide the IP networking configuration and the address of the DNS server to the nodes at RHCOS install time. These can be passed as boot arguments if you are installing from an ISO image. See the Installing RHCOS and starting the OpenShift Container Platform bootstrap process section for more information about static IP provisioning and advanced networking options.
-
Define the hostnames of your cluster nodes in your DHCP server configuration. See the Setting the cluster node hostnames through DHCP section for details about hostname considerations.
If you are not using a DHCP service, the cluster nodes obtain their hostname through a reverse DNS lookup.
-
-
Ensure that your network infrastructure provides the required network connectivity between the cluster components. See the Networking requirements for user-provisioned infrastructure section for details about the requirements.
-
Configure your firewall to enable the ports required for the OpenShift Container Platform cluster components to communicate. See Networking requirements for user-provisioned infrastructure section for details about the ports that are required.
By default, port
1936is accessible for an OpenShift Container Platform cluster, because each control plane node needs access to this port.Avoid using the Ingress load balancer to expose this port, because doing so might result in the exposure of sensitive information, such as statistics and metrics, related to Ingress Controllers.
-
Setup the required DNS infrastructure for your cluster.
-
Configure DNS name resolution for the Kubernetes API, the application wildcard, the bootstrap machine, the control plane machines, and the compute machines.
-
Configure reverse DNS resolution for the Kubernetes API, the bootstrap machine, the control plane machines, and the compute machines.
See the User-provisioned DNS requirements section for more information about the OpenShift Container Platform DNS requirements.
-
-
Validate your DNS configuration.
-
From your installation node, run DNS lookups against the record names of the Kubernetes API, the wildcard routes, and the cluster nodes. Validate that the IP addresses in the responses correspond to the correct components.
-
From your installation node, run reverse DNS lookups against the IP addresses of the load balancer and the cluster nodes. Validate that the record names in the responses correspond to the correct components.
See the Validating DNS resolution for user-provisioned infrastructure section for detailed DNS validation steps.
-
-
Provision the required API and application ingress load balancing infrastructure. See the Load balancing requirements for user-provisioned infrastructure section for more information about the requirements.
|
Some load balancing solutions require the DNS name resolution for the cluster nodes to be in place before the load balancing is initialized. |
Validating DNS resolution for user-provisioned infrastructure
You can validate your DNS configuration before installing OpenShift Container Platform on user-provisioned infrastructure.
|
The validation steps detailed in this section must succeed before you install your cluster. |
Prerequisites
-
You have configured the required DNS records for your user-provisioned infrastructure.
Procedure
-
From your installation node, run DNS lookups against the record names of the Kubernetes API, the wildcard routes, and the cluster nodes. Validate that the IP addresses contained in the responses correspond to the correct components.
-
Perform a lookup against the Kubernetes API record name. Check that the result points to the IP address of the API load balancer:
$ dig +noall +answer @<nameserver_ip> api.<cluster_name>.<base_domain> (1)1 Replace <nameserver_ip>with the IP address of the nameserver,<cluster_name>with your cluster name, and<base_domain>with your base domain name.Example outputapi.ocp4.example.com. 604800 IN A 192.168.1.5 -
Perform a lookup against the Kubernetes internal API record name. Check that the result points to the IP address of the API load balancer:
$ dig +noall +answer @<nameserver_ip> api-int.<cluster_name>.<base_domain>Example outputapi-int.ocp4.example.com. 604800 IN A 192.168.1.5 -
Test an example
*.apps.<cluster_name>.<base_domain>DNS wildcard lookup. All of the application wildcard lookups must resolve to the IP address of the application ingress load balancer:$ dig +noall +answer @<nameserver_ip> random.apps.<cluster_name>.<base_domain>Example outputrandom.apps.ocp4.example.com. 604800 IN A 192.168.1.5In the example outputs, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.
You can replace
randomwith another wildcard value. For example, you can query the route to the OpenShift Container Platform console:$ dig +noall +answer @<nameserver_ip> console-openshift-console.apps.<cluster_name>.<base_domain>Example outputconsole-openshift-console.apps.ocp4.example.com. 604800 IN A 192.168.1.5 -
Run a lookup against the bootstrap DNS record name. Check that the result points to the IP address of the bootstrap node:
$ dig +noall +answer @<nameserver_ip> bootstrap.<cluster_name>.<base_domain>Example outputbootstrap.ocp4.example.com. 604800 IN A 192.168.1.96 -
Use this method to perform lookups against the DNS record names for the control plane and compute nodes. Check that the results correspond to the IP addresses of each node.
-
-
From your installation node, run reverse DNS lookups against the IP addresses of the load balancer and the cluster nodes. Validate that the record names contained in the responses correspond to the correct components.
-
Perform a reverse lookup against the IP address of the API load balancer. Check that the response includes the record names for the Kubernetes API and the Kubernetes internal API:
$ dig +noall +answer @<nameserver_ip> -x 192.168.1.5Example output5.1.168.192.in-addr.arpa. 604800 IN PTR api-int.ocp4.example.com. (1) 5.1.168.192.in-addr.arpa. 604800 IN PTR api.ocp4.example.com. (2)1 Provides the record name for the Kubernetes internal API. 2 Provides the record name for the Kubernetes API. A PTR record is not required for the OpenShift Container Platform application wildcard. No validation step is needed for reverse DNS resolution against the IP address of the application ingress load balancer.
-
Perform a reverse lookup against the IP address of the bootstrap node. Check that the result points to the DNS record name of the bootstrap node:
$ dig +noall +answer @<nameserver_ip> -x 192.168.1.96Example output96.1.168.192.in-addr.arpa. 604800 IN PTR bootstrap.ocp4.example.com. -
Use this method to perform reverse lookups against the IP addresses for the control plane and compute nodes. Check that the results correspond to the DNS record names of each node.
-
Generating a key pair for cluster node SSH access
During an OpenShift Container Platform installation, you can provide an SSH public key to the installation program. The key is passed to the Red Hat Enterprise Linux CoreOS (RHCOS) nodes through their Ignition config files and is used to authenticate SSH access to the nodes. The key is added to the ~/.ssh/authorized_keys list for the core user on each node, which enables password-less authentication.
After the key is passed to the nodes, you can use the key pair to SSH in to the RHCOS nodes as the user core. To access the nodes through SSH, the private key identity must be managed by SSH for your local user.
If you want to SSH in to your cluster nodes to perform installation debugging or disaster recovery, you must provide the SSH public key during the installation process. The ./openshift-install gather command also requires the SSH public key to be in place on the cluster nodes.
|
Do not skip this procedure in production environments, where disaster recovery and debugging is required. |
|
You must use a local key, not one that you configured with platform-specific approaches such as AWS key pairs. |
Procedure
-
If you do not have an existing SSH key pair on your local machine to use for authentication onto your cluster nodes, create one. For example, on a computer that uses a Linux operating system, run the following command:
$ ssh-keygen -t ed25519 -N '' -f <path>/<file_name> (1)1 Specify the path and file name, such as ~/.ssh/id_ed25519, of the new SSH key. If you have an existing key pair, ensure your public key is in the your~/.sshdirectory. -
View the public SSH key:
$ cat <path>/<file_name>.pubFor example, run the following to view the
~/.ssh/id_ed25519.pubpublic key:$ cat ~/.ssh/id_ed25519.pub -
Add the SSH private key identity to the SSH agent for your local user, if it has not already been added. SSH agent management of the key is required for password-less SSH authentication onto your cluster nodes, or if you want to use the
./openshift-install gathercommand.On some distributions, default SSH private key identities such as
~/.ssh/id_rsaand~/.ssh/id_dsaare managed automatically.-
If the
ssh-agentprocess is not already running for your local user, start it as a background task:$ eval "$(ssh-agent -s)"Example outputAgent pid 31874
-
-
Add your SSH private key to the
ssh-agent:$ ssh-add <path>/<file_name> (1)1 Specify the path and file name for your SSH private key, such as ~/.ssh/id_ed25519Example outputIdentity added: /home/<you>/<path>/<file_name> (<computer_name>)
Next steps
-
When you install OpenShift Container Platform, provide the SSH public key to the installation program. If you install a cluster on infrastructure that you provision, you must provide the key to the installation program.
VMware vSphere region and zone enablement
You can deploy an OpenShift Container Platform cluster to multiple vSphere datacenters that run in a single VMware vCenter. Each datacenter can run multiple clusters. This configuration reduces the risk of a hardware failure or network outage that can cause your cluster to fail. To enable regions and zones, you must define multiple failure domains for your OpenShift Container Platform cluster.
|
The VMware vSphere region and zone enablement feature requires the vSphere Container Storage Interface (CSI) driver as the default storage driver in the cluster. As a result, the feature only available on a newly installed cluster. A cluster that was upgraded from a previous release defaults to using the in-tree vSphere driver, so you must enable CSI automatic migration for the cluster. You can then configure multiple regions and zones for the upgraded cluster. |
The default installation configuration deploys a cluster to a single vSphere datacenter. If you want to deploy a cluster to multiple vSphere datacenters, you must create an installation configuration file that enables the region and zone feature.
The default install-config.yaml file includes vcenters and failureDomains fields, where you can specify multiple vSphere datacenters and clusters for your OpenShift Container Platform cluster. You can leave these fields blank if you want to install an OpenShift Container Platform cluster in a vSphere environment that consists of single datacenter.
The following list describes terms associated with defining zones and regions for your cluster:
-
Failure domain: Establishes the relationships between a region and zone. You define a failure domain by using vCenter objects, such as a
datastoreobject. A failure domain defines the vCenter location for OpenShift Container Platform cluster nodes. -
Region: Specifies a vCenter datacenter. You define a region by using a tag from the
openshift-regiontag category. -
Zone: Specifies a vCenter cluster. You define a zone by using a tag from the
openshift-zonetag category.
|
If you plan on specifying more than one failure domain in your |
You must create a vCenter tag for each vCenter datacenter, which represents a region. Additionally, you must create a vCenter tag for each cluster than runs in a datacenter, which represents a zone. After you create the tags, you must attach each tag to their respective datacenters and clusters.
The following table outlines an example of the relationship among regions, zones, and tags for a configuration with multiple vSphere datacenters running in a single VMware vCenter.
| Datacenter (region) | Cluster (zone) | Tags |
|---|---|---|
us-east |
us-east-1 |
us-east-1a |
us-east-1b |
||
us-east-2 |
us-east-2a |
|
us-east-2b |
||
us-west |
us-west-1 |
us-west-1a |
us-west-1b |
||
us-west-2 |
us-west-2a |
|
us-west-2b |
Manually creating the installation configuration file
Installing the cluster requires that you manually create the installation configuration file.
Prerequisites
-
You have an SSH public key on your local machine to provide to the installation program. The key will be used for SSH authentication onto your cluster nodes for debugging and disaster recovery.
-
You have obtained the OpenShift Container Platform installation program and the pull secret for your cluster.
-
Obtain the
imageContentSourcessection from the output of the command to mirror the repository. -
Obtain the contents of the certificate for your mirror registry.
Procedure
-
Create an installation directory to store your required installation assets in:
$ mkdir <installation_directory>You must create a directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OpenShift Container Platform version.
-
Customize the sample
install-config.yamlfile template that is provided and save it in the<installation_directory>.You must name this configuration file
install-config.yaml.-
Unless you use a registry that RHCOS trusts by default, such as
docker.io, you must provide the contents of the certificate for your mirror repository in theadditionalTrustBundlesection. In most cases, you must provide the certificate for your mirror. -
You must include the
imageContentSourcessection from the output of the command to mirror the repository.
-
-
Back up the
install-config.yamlfile so that you can use it to install multiple clusters.The
install-config.yamlfile is consumed during the next step of the installation process. You must back it up now.
Installation configuration parameters
Before you deploy an OpenShift Container Platform cluster, you provide parameter values to describe your account on the cloud platform that hosts your cluster and optionally customize your cluster’s platform. When you create the install-config.yaml installation configuration file, you provide values for the required parameters through the command line. If you customize your cluster, you can modify the install-config.yaml file to provide more details about the platform.
|
After installation, you cannot modify these parameters in the |
Required configuration parameters
Required installation configuration parameters are described in the following table:
| Parameter | Description | Values |
|---|---|---|
|
The API version for the |
String |
|
The base domain of your cloud provider. The base domain is used to create routes to your OpenShift Container Platform cluster components. The full DNS name for your cluster is a combination of the |
A fully-qualified domain or subdomain name, such as |
|
Kubernetes resource |
Object |
|
The name of the cluster. DNS records for the cluster are all subdomains of |
String of lowercase letters and hyphens ( |
|
The configuration for the specific platform upon which to perform the installation: |
Object |
|
Get a pull secret from the Red Hat OpenShift Cluster Manager to authenticate downloading container images for OpenShift Container Platform components from services such as Quay.io. |
|
Network configuration parameters
You can customize your installation configuration based on the requirements of your existing network infrastructure. For example, you can expand the IP address block for the cluster network or provide different IP address blocks than the defaults.
Only IPv4 addresses are supported.
|
Globalnet is not supported with Red Hat OpenShift Data Foundation disaster recovery solutions. For regional disaster recovery scenarios, ensure that you use a nonoverlapping range of private IP addresses for the cluster and service networks in each cluster. |
| Parameter | Description | Values | ||
|---|---|---|---|---|
|
The configuration for the cluster network. |
Object
|
||
|
The Red Hat OpenShift Networking network plugin to install. |
Either |
||
|
The IP address blocks for pods. The default value is If you specify multiple IP address blocks, the blocks must not overlap. |
An array of objects. For example: |
||
|
Required if you use An IPv4 network. |
An IP address block in Classless Inter-Domain Routing (CIDR) notation.
The prefix length for an IPv4 block is between |
||
|
The subnet prefix length to assign to each individual node. For example, if |
A subnet prefix. The default value is |
||
|
The IP address block for services. The default value is The OpenShift SDN and OVN-Kubernetes network plugins support only a single IP address block for the service network. |
An array with an IP address block in CIDR format. For example: |
||
|
The IP address blocks for machines. If you specify multiple IP address blocks, the blocks must not overlap. |
An array of objects. For example: |
||
|
Required if you use |
An IP network block in CIDR notation. For example,
|
Optional configuration parameters
Optional installation configuration parameters are described in the following table:
| Parameter | Description | Values | ||||
|---|---|---|---|---|---|---|
|
A PEM-encoded X.509 certificate bundle that is added to the nodes' trusted certificate store. This trust bundle may also be used when a proxy has been configured. |
String |
||||
|
Controls the installation of optional core cluster components. You can reduce the footprint of your OpenShift Container Platform cluster by disabling optional components. For more information, see the "Cluster capabilities" page in Installing. |
String array |
||||
|
Selects an initial set of optional capabilities to enable. Valid values are |
String |
||||
|
Extends the set of optional capabilities beyond what you specify in |
String array |
||||
|
Enables workload partitioning, which isolates OpenShift Container Platform services, cluster management workloads, and infrastructure pods to run on a reserved set of CPUs. Workload partitioning can only be enabled during installation and cannot be disabled after installation. While this field enables workload partitioning, it does not configure workloads to use specific CPUs. For more information, see the Workload partitioning page in the Scalability and Performance section. |
|
||||
|
The configuration for the machines that comprise the compute nodes. |
Array of |
||||
|
Determines the instruction set architecture of the machines in the pool. Currently, clusters with varied architectures are not supported. All pools must specify the same architecture. Valid values are |
String |
||||
compute: hyperthreading: |
Whether to enable or disable simultaneous multithreading, or
|
|
||||
|
Required if you use |
|
||||
|
Required if you use |
|
||||
|
The number of compute machines, which are also known as worker machines, to provision. |
A positive integer greater than or equal to |
||||
|
Enables the cluster for a feature set. A feature set is a collection of OpenShift Container Platform features that are not enabled by default. For more information about enabling a feature set during installation, see "Enabling features using feature gates". |
String. The name of the feature set to enable, such as |
||||
|
The configuration for the machines that comprise the control plane. |
Array of |
||||
|
Determines the instruction set architecture of the machines in the pool. Currently, clusters with varied architectures are not supported. All pools must specify the same architecture. Valid values are |
String |
||||
controlPlane: hyperthreading: |
Whether to enable or disable simultaneous multithreading, or
|
|
||||
|
Required if you use |
|
||||
|
Required if you use |
|
||||
|
The number of control plane machines to provision. |
The only supported value is |
||||
|
The Cloud Credential Operator (CCO) mode. If no mode is specified, the CCO dynamically tries to determine the capabilities of the provided credentials, with a preference for mint mode on the platforms where multiple modes are supported.
|
|
||||
|
Sources and repositories for the release-image content. |
Array of objects. Includes a |
||||
|
Required if you use |
String |
||||
|
Specify one or more repositories that may also contain the same images. |
Array of strings |
||||
|
How to publish or expose the user-facing endpoints of your cluster, such as the Kubernetes API, OpenShift routes. |
Setting this field to
|
||||
|
The SSH key to authenticate access to your cluster machines.
|
For example, |
-
Not all CCO modes are supported for all cloud providers. For more information about CCO modes, see the "Managing cloud provider credentials" entry in the Authentication and authorization content.
Additional VMware vSphere configuration parameters
Additional VMware vSphere configuration parameters are described in the following table.
|
The |
| Parameter | Description | Values | ||
|---|---|---|---|---|
platform: vsphere: |
Describes your account on the cloud platform that hosts your cluster. You can use the parameter to customize the platform. If you provide additional configuration settings for compute and control plane machines in the machine pool, the parameter is not required. You can only specify one vCenter server for your OpenShift Container Platform cluster. |
A dictionary of vSphere configuration objects |
||
platform:
vsphere:
apiVIPs: |
Virtual IP (VIP) addresses that you configured for control plane API access.
|
Multiple IP addresses |
||
platform:
vsphere:
diskType: |
Optional: The disk provisioning method. This value defaults to the vSphere default storage policy if not set. |
Valid values are |
||
platform:
vsphere:
failureDomains:
region: |
If you define multiple failure domains for your cluster, you must attach the tag to each vCenter datacenter. To define a region, use a tag from the |
String |
||
platform:
vsphere:
failureDomains:
server: |
Specifies the fully-qualified hostname or IP address of the VMware vCenter server, so that a client can access failure domain resources. You must apply the |
String |
||
platform:
vsphere:
failureDomains:
zone: |
If you define multiple failure domains for your cluster, you must attach a tag to each vCenter cluster. To define a zone, use a tag from the |
String |
||
platform:
vsphere:
failureDomains:
topology:
datacenter: |
Lists and defines the datacenters where OpenShift Container Platform virtual machines (VMs) operate.
The list of datacenters must match the list of datacenters specified in the |
String |
||
platform:
vsphere:
failureDomains:
topology:
datastore: |
Specifies the path to a vSphere datastore that stores virtual machines files for a failure domain. You must apply the |
String |
||
platform:
vsphere:
failureDomains:
topology:
folder: |
Optional: The absolute path of an existing folder where the user creates the virtual machines, for example, |
String |
||
platform:
vsphere:
failureDomains:
topology:
networks: |
Lists any network in the vCenter instance that contains the virtual IP addresses and DNS records that you configured. |
String |
||
platform:
vsphere:
failureDomains:
topology:
resourcePool: |
Optional: The absolute path of an existing resource pool where the installation program creates the virtual machines, for example, |
String |
||
platform:
vsphere:
ingressVIPs: |
Virtual IP (VIP) addresses that you configured for cluster Ingress.
|
Multiple IP addresses |
||
platform:
vsphere:
vcenters: |
Configures the connection details so that services can communicate with a vCenter server. Currently, only a single vCenter server is supported. |
An array of vCenter configuration objects. |
||
platform:
vsphere:
vcenters:
datacenters: |
Lists and defines the datacenters where OpenShift Container Platform virtual machines (VMs) operate. The list of datacenters must match the list of datacenters specified in the |
String |
||
platform:
vsphere:
vcenters:
password: |
The password associated with the vSphere user. |
String |
||
platform:
vsphere:
vcenters:
port: |
The port number used to communicate with the vCenter server. |
Integer |
||
platform:
vsphere:
vcenters:
server: |
The fully qualified host name (FQHN) or IP address of the vCenter server. |
String |
||
platform:
vsphere:
vcenters:
user: |
The username associated with the vSphere user. |
String |
Deprecated VMware vSphere configuration parameters
In OpenShift Container Platform 4.13, the following vSphere configuration parameters are deprecated. You can continue to use these parameters, but the installation program does not automatically specify these parameters in the install-config.yaml file.
The following table lists each deprecated vSphere configuration parameter.
|
The |
| Parameter | Description | Values | ||
|---|---|---|---|---|
platform:
vsphere:
apiVIP: |
The virtual IP (VIP) address that you configured for control plane API access.
|
An IP address, for example |
||
platform:
vsphere:
cluster: |
The vCenter cluster to install the OpenShift Container Platform cluster in. |
String |
||
platform:
vsphere:
datacenter: |
Defines the datacenter where OpenShift Container Platform virtual machines (VMs) operate. |
String |
||
platform:
vsphere:
defaultDatastore: |
The name of the default datastore to use for provisioning volumes. |
String |
||
platform:
vsphere:
folder: |
Optional: The absolute path of an existing folder where the installation program creates the virtual machines. If you do not provide this value, the installation program creates a folder that is named with the infrastructure ID in the data center virtual machine folder. |
String, for example, |
||
platform:
vsphere:
ingressVIP: |
Virtual IP (VIP) addresses that you configured for cluster Ingress.
|
An IP address, for example |
||
platform:
vsphere:
network: |
The network in the vCenter instance that contains the virtual IP addresses and DNS records that you configured. |
String |
||
platform:
vsphere:
password: |
The password for the vCenter user name. |
String |
||
platform:
vsphere:
resourcePool: |
Optional: The absolute path of an existing resource pool where the installation program creates the virtual machines. If you do not specify a value, the installation program installs the resources in the root of the cluster under |
String, for example, |
||
platform:
vsphere:
username: |
The user name to use to connect to the vCenter instance with. This user must have at least the roles and privileges that are required for static or dynamic persistent volume provisioning in vSphere. |
String |
||
platform:
vsphere:
vCenter: |
The fully-qualified hostname or IP address of a vCenter server. |
String |
Optional VMware vSphere machine pool configuration parameters
Optional VMware vSphere machine pool configuration parameters are described in the following table.
|
The |
| Parameter | Description | Values |
|---|---|---|
|
The location from which the installation program downloads the RHCOS image. You must set this parameter to perform an installation in a restricted network. |
An HTTP or HTTPS URL, optionally with a SHA-256 checksum. For example, |
|
The size of the disk in gigabytes. |
Integer |
|
The total number of virtual processor cores to assign a virtual machine. The value of |
Integer |
|
The number of cores per socket in a virtual machine. The number of virtual sockets on the virtual machine is |
Integer |
|
The size of a virtual machine’s memory in megabytes. |
Integer |
Sample install-config.yaml file for VMware vSphere
You can customize the install-config.yaml file to specify more details about
your OpenShift Container Platform cluster’s platform or modify the values of the required
parameters.
additionalTrustBundlePolicy: Proxyonly
apiVersion: v1
baseDomain: example.com (1)
compute: (2)
- architecture: amd64
name: <worker_node>
platform: {}
replicas: 0 (3)
controlPlane: (2)
architecture: amd64
name: <parent_node>
platform: {}
replicas: 3 (4)
metadata:
creationTimestamp: null
name: test (5)
networking:
---
platform:
vsphere:
failureDomains: (6)
- name: <failure_domain_name>
region: <default_region_name>
server: <fully_qualified_domain_name>
topology:
computeCluster: "/<datacenter>/host/<cluster>"
datacenter: <datacenter> (7)
datastore: "/<datacenter>/datastore/<datastore>" (8)
networks:
- <VM_Network_name>
resourcePool: "/<datacenter>/host/<cluster>/Resources/<resourcePool>" (9)
folder: "/<datacenter_name>/vm/<folder_name>/<subfolder_name>" (10)
zone: <default_zone_name>
vcenters:
- datacenters:
- <datacenter>
password: <password> (11)
port: 443
server: <fully_qualified_domain_name> (12)
user: administrator@vsphere.local
diskType: thin (13)
fips: false (14)
pullSecret: '{"auths":{"<local_registry>": {"auth": "<credentials>","email": "you@example.com"}}}' (15)
sshKey: 'ssh-ed25519 AAAA...' (16)
additionalTrustBundle: | (17)
-----BEGIN CERTIFICATE-----
ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
-----END CERTIFICATE-----
imageContentSources: (18)
- mirrors:
- <mirror_host_name>:<mirror_port>/<repo_name>/release
source: <source_image_1>
- mirrors:
- <mirror_host_name>:<mirror_port>/<repo_name>/release-images
source: <source_image_2>| 1 | The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name. | ||
| 2 | The controlPlane section is a single mapping, but the compute section is a
sequence of mappings. To meet the requirements of the different data structures,
the first line of the compute section must begin with a hyphen, -, and the
first line of the controlPlane section must not. Both sections define a single machine pool, so only one control plane is used. OpenShift Container Platform does not support defining multiple compute pools. |
||
| 3 | You must set the value of the replicas parameter to 0. This parameter
controls the number of workers that the cluster creates and manages for you,
which are functions that the cluster does not perform when you
use user-provisioned infrastructure. You must manually deploy worker
machines for the cluster to use before you finish installing OpenShift Container Platform. |
||
| 4 | The number of control plane machines that you add to the cluster. Because the cluster uses this values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy. | ||
| 5 | The cluster name that you specified in your DNS records. | ||
| 6 | Establishes the relationships between a region and zone. You define a failure domain by using vCenter objects, such as a datastore object. A failure domain defines the vCenter location for OpenShift Container Platform cluster nodes. |
||
| 7 | The vSphere datacenter. | ||
| 8 | The path to the vSphere datastore that holds virtual machine files, templates, and ISO images.
|
||
| 9 | Optional: For installer-provisioned infrastructure, the absolute path of an existing resource pool where the installation program creates the virtual machines, for example, /<datacenter_name>/host/<cluster_name>/Resources/<resource_pool_name>/<optional_nested_resource_pool_name>. If you do not specify a value, resources are installed in the root of the cluster /example_datacenter/host/example_cluster/Resources. |
||
| 10 | Optional: For installer-provisioned infrastructure, the absolute path of an existing folder where the installation program creates the virtual machines, for example, /<datacenter_name>/vm/<folder_name>/<subfolder_name>. If you do not provide this value, the installation program creates a top-level folder in the datacenter virtual machine folder that is named with the infrastructure ID. If you are providing the infrastructure for the cluster and you do not want to use the default StorageClass object, named thin, you can omit the folder parameter from the install-config.yaml file. |
||
| 11 | The password associated with the vSphere user. | ||
| 12 | The fully-qualified hostname or IP address of the vCenter server.
|
||
| 13 | The vSphere disk provisioning method. | ||
| 14 | Whether to enable or disable FIPS mode. By default, FIPS mode is not enabled. If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead.
|
||
| 15 | For <local_registry>, specify the registry domain name, and optionally the
port, that your mirror registry uses to serve content. For example
registry.example.com or registry.example.com:5000. For <credentials>,
specify the base64-encoded user name and password for your mirror registry. |
||
| 16 | The public portion of the default SSH key for the core user in
Red Hat Enterprise Linux CoreOS (RHCOS).
|
||
| 17 | Provide the contents of the certificate file that you used for your mirror registry. | ||
| 18 | Provide the imageContentSources section from the output of the command to
mirror the repository. |
Configuring the cluster-wide proxy during installation
Production environments can deny direct access to the internet and instead have
an HTTP or HTTPS proxy available. You can configure a new OpenShift Container Platform
cluster to use a proxy by configuring the proxy settings in the
install-config.yaml file.
Prerequisites
-
You have an existing
install-config.yamlfile. -
You reviewed the sites that your cluster requires access to and determined whether any of them need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. You added sites to the
Proxyobject’sspec.noProxyfield to bypass the proxy if necessary.The
Proxyobjectstatus.noProxyfield is populated with the values of thenetworking.machineNetwork[].cidr,networking.clusterNetwork[].cidr, andnetworking.serviceNetwork[]fields from your installation configuration.For installations on Amazon Web Services (AWS), Google Cloud Platform (GCP), Microsoft Azure, and Red Hat OpenStack Platform (RHOSP), the
Proxyobjectstatus.noProxyfield is also populated with the instance metadata endpoint (169.254.169.254).
Procedure
-
Edit your
install-config.yamlfile and add the proxy settings. For example:apiVersion: v1 baseDomain: my.domain.com proxy: httpProxy: http://<username>:<pswd>@<ip>:<port> (1) httpsProxy: https://<username>:<pswd>@<ip>:<port> (2) noProxy: example.com (3) additionalTrustBundle: | (4) -----BEGIN CERTIFICATE----- <MY_TRUSTED_CA_CERT> -----END CERTIFICATE----- additionalTrustBundlePolicy: <policy_to_add_additionalTrustBundle> (5)1 A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http.2 A proxy URL to use for creating HTTPS connections outside the cluster. 3 A comma-separated list of destination domain names, IP addresses, or other network CIDRs to exclude from proxying. Preface a domain with .to match subdomains only. For example,.y.commatchesx.y.com, but noty.com. Use*to bypass the proxy for all destinations. You must include vCenter’s IP address and the IP range that you use for its machines.4 If provided, the installation program generates a config map that is named user-ca-bundlein theopenshift-confignamespace that contains one or more additional CA certificates that are required for proxying HTTPS connections. The Cluster Network Operator then creates atrusted-ca-bundleconfig map that merges these contents with the Red Hat Enterprise Linux CoreOS (RHCOS) trust bundle, and this config map is referenced in thetrustedCAfield of theProxyobject. TheadditionalTrustBundlefield is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.5 Optional: The policy to determine the configuration of the Proxyobject to reference theuser-ca-bundleconfig map in thetrustedCAfield. The allowed values areProxyonlyandAlways. UseProxyonlyto reference theuser-ca-bundleconfig map only whenhttp/httpsproxy is configured. UseAlwaysto always reference theuser-ca-bundleconfig map. The default value isProxyonly.The installation program does not support the proxy
readinessEndpointsfield.If the installer times out, restart and then complete the deployment by using the
wait-forcommand of the installer. For example:$ ./openshift-install wait-for install-complete --log-level debug -
Save the file and reference it when installing OpenShift Container Platform.
The installation program creates a cluster-wide proxy that is named cluster that uses the proxy
settings in the provided install-config.yaml file. If no proxy settings are
provided, a cluster Proxy object is still created, but it will have a nil
spec.
|
Only the |
Configuring regions and zones for a VMware vCenter
You can modify the default installation configuration file, so that you can deploy an OpenShift Container Platform cluster to multiple vSphere datacenters that run in a single VMware vCenter.
The default install-config.yaml file configuration from the previous release of OpenShift Container Platform is deprecated. You can continue to use the deprecated default configuration, but the openshift-installer will prompt you with a warning message that indicates the use of deprecated fields in the configuration file.
|
The example uses the |
Prerequisites
-
You have an existing
install-config.yamlinstallation configuration file.You must specify at least one failure domain for your OpenShift Container Platform cluster, so that you can provision datacenter objects for your VMware vCenter server. Consider specifying multiple failure domains if you need to provision virtual machine nodes in different datacenters, clusters, datastores, and other components. To enable regions and zones, you must define multiple failure domains for your OpenShift Container Platform cluster.
Procedure
-
Enter the following
govccommand-line tool commands to create theopenshift-regionandopenshift-zonevCenter tag categories:If you specify different names for the
openshift-regionandopenshift-zonevCenter tag categories, the installation of the OpenShift Container Platform cluster fails.$ govc tags.category.create -d "OpenShift region" openshift-region$ govc tags.category.create -d "OpenShift zone" openshift-zone -
To create a region tag for each region vSphere datacenter where you want to deploy your cluster, enter the following command in your terminal:
$ govc tags.create -c <region_tag_category> <region_tag> -
To create a zone tag for each vSphere cluster where you want to deploy your cluster, enter the following command:
$ govc tags.create -c <zone_tag_category> <zone_tag> -
Attach region tags to each vCenter datacenter object by entering the following command:
$ govc tags.attach -c <region_tag_category> <region_tag_1> /<datacenter_1> -
Attach the zone tags to each vCenter datacenter object by entering the following command:
$ govc tags.attach -c <zone_tag_category> <zone_tag_1> /<datacenter_1>/host/vcs-mdcnc-workload-1 -
Change to the directory that contains the installation program and initialize the cluster deployment according to your chosen installation requirements.
Sample
install-config.yaml file with multiple datacenters defined in a vSphere center---
compute:
---
vsphere:
zones:
- "<machine_pool_zone_1>"
- "<machine_pool_zone_2>"
---
controlPlane:
---
vsphere:
zones:
- "<machine_pool_zone_1>"
- "<machine_pool_zone_2>"
---
platform:
vsphere:
vcenters:
---
datacenters:
- <datacenter1_name>
- <datacenter2_name>
failureDomains:
- name: <machine_pool_zone_1>
region: <region_tag_1>
zone: <zone_tag_1>
server: <fully_qualified_domain_name>
topology:
datacenter: <datacenter1>
computeCluster: "/<datacenter1>/host/<cluster1>"
networks:
- <VM_Network1_name>
datastore: "/<datacenter1>/datastore/<datastore1>"
resourcePool: "/<datacenter1>/host/<cluster1>/Resources/<resourcePool1>"
folder: "/<datacenter1>/vm/<folder1>"
- name: <machine_pool_zone_2>
region: <region_tag_2>
zone: <zone_tag_2>
server: <fully_qualified_domain_name>
topology:
datacenter: <datacenter2>
computeCluster: "/<datacenter2>/host/<cluster2>"
networks:
- <VM_Network2_name>
datastore: "/<datacenter2>/datastore/<datastore2>"
resourcePool: "/<datacenter2>/host/<cluster2>/Resources/<resourcePool2>"
folder: "/<datacenter2>/vm/<folder2>"
---Creating the Kubernetes manifest and Ignition config files
Because you must modify some cluster definition files and manually start the cluster machines, you must generate the Kubernetes manifest and Ignition config files that the cluster needs to configure the machines.
The installation configuration file transforms into the Kubernetes manifests. The manifests wrap into the Ignition configuration files, which are later used to configure the cluster machines.
|
Prerequisites
-
You obtained the OpenShift Container Platform installation program. For a restricted network installation, these files are on your mirror host.
-
You created the
install-config.yamlinstallation configuration file.
Procedure
-
Change to the directory that contains the OpenShift Container Platform installation program and generate the Kubernetes manifests for the cluster:
$ ./openshift-install create manifests --dir <installation_directory> (1)1 For <installation_directory>, specify the installation directory that contains theinstall-config.yamlfile you created. -
Remove the Kubernetes manifest files that define the control plane machines and compute machine sets:
$ rm -f openshift/99_openshift-cluster-api_master-machines-*.yaml openshift/99_openshift-cluster-api_worker-machineset-*.yamlBecause you create and manage these resources yourself, you do not have to initialize them.
-
You can preserve the compute machine set files to create compute machines by using the machine API, but you must update references to them to match your environment.
-
-
Check that the
mastersSchedulableparameter in the<installation_directory>/manifests/cluster-scheduler-02-config.ymlKubernetes manifest file is set tofalse. This setting prevents pods from being scheduled on the control plane machines:-
Open the
<installation_directory>/manifests/cluster-scheduler-02-config.ymlfile. -
Locate the
mastersSchedulableparameter and ensure that it is set tofalse. -
Save and exit the file.
-
-
To create the Ignition configuration files, run the following command from the directory that contains the installation program:
$ ./openshift-install create ignition-configs --dir <installation_directory> (1)1 For <installation_directory>, specify the same installation directory.Ignition config files are created for the bootstrap, control plane, and compute nodes in the installation directory. The
kubeadmin-passwordandkubeconfigfiles are created in the./<installation_directory>/authdirectory:. ├── auth │ ├── kubeadmin-password │ └── kubeconfig ├── bootstrap.ign ├── master.ign ├── metadata.json └── worker.ign
Extracting the infrastructure name
The Ignition config files contain a unique cluster identifier that you can use to uniquely identify your cluster in VMware Cloud on AWS. If you plan to use the cluster identifier as the name of your virtual machine folder, you must extract it.
Prerequisites
-
You obtained the OpenShift Container Platform installation program and the pull secret for your cluster.
-
You generated the Ignition config files for your cluster.
-
You installed the
jqpackage.
Procedure
-
To extract and view the infrastructure name from the Ignition config file metadata, run the following command:
$ jq -r .infraID <installation_directory>/metadata.json (1)1 For <installation_directory>, specify the path to the directory that you stored the installation files in.Example outputopenshift-vw9j6 (1)1 The output of this command is your cluster name and a random string.
Installing RHCOS and starting the OpenShift Container Platform bootstrap process
To install OpenShift Container Platform on user-provisioned infrastructure on VMware vSphere, you must install Red Hat Enterprise Linux CoreOS (RHCOS) on vSphere hosts. When you install RHCOS, you must provide the Ignition config file that was generated by the OpenShift Container Platform installation program for the type of machine you are installing. If you have configured suitable networking, DNS, and load balancing infrastructure, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS machines have rebooted.
Prerequisites
-
You have obtained the Ignition config files for your cluster.
-
You have access to an HTTP server that you can access from your computer and that the machines that you create can access.
-
You have created a vSphere cluster.
Procedure
-
Upload the bootstrap Ignition config file, which is named
<installation_directory>/bootstrap.ign, that the installation program created to your HTTP server. Note the URL of this file. -
Save the following secondary Ignition config file for your bootstrap node to your computer as
<installation_directory>/merge-bootstrap.ign:{ "ignition": { "config": { "merge": [ { "source": "<bootstrap_ignition_config_url>", (1) "verification": {} } ] }, "timeouts": {}, "version": "3.2.0" }, "networkd": {}, "passwd": {}, "storage": {}, "systemd": {} }1 Specify the URL of the bootstrap Ignition config file that you hosted. When you create the virtual machine (VM) for the bootstrap machine, you use this Ignition config file.
-
Locate the following Ignition config files that the installation program created:
-
<installation_directory>/master.ign -
<installation_directory>/worker.ign -
<installation_directory>/merge-bootstrap.ign
-
-
Convert the Ignition config files to Base64 encoding. Later in this procedure, you must add these files to the extra configuration parameter
guestinfo.ignition.config.datain your VM.For example, if you use a Linux operating system, you can use the
base64command to encode the files.$ base64 -w0 <installation_directory>/master.ign > <installation_directory>/master.64$ base64 -w0 <installation_directory>/worker.ign > <installation_directory>/worker.64$ base64 -w0 <installation_directory>/merge-bootstrap.ign > <installation_directory>/merge-bootstrap.64If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
-
Obtain the RHCOS OVA image. Images are available from the RHCOS image mirror page.
The RHCOS images might not change with every release of OpenShift Container Platform. You must download an image with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image version that matches your OpenShift Container Platform version if it is available.
The filename contains the OpenShift Container Platform version number in the format
rhcos-vmware.<architecture>.ova. -
In the vSphere Client, create a folder in your datacenter to store your VMs.
-
Click the VMs and Templates view.
-
Right-click the name of your datacenter.
-
Click New Folder → New VM and Template Folder.
-
In the window that is displayed, enter the folder name. If you did not specify an existing folder in the
install-config.yamlfile, then create a folder with the same name as the infrastructure ID. You use this folder name so vCenter dynamically provisions storage in the appropriate location for its Workspace configuration.
-
-
In the vSphere Client, create a template for the OVA image and then clone the template as needed.
In the following steps, you create a template and then clone the template for all of your cluster machines. You then provide the location for the Ignition config file for that cloned machine type when you provision the VMs.
-
From the Hosts and Clusters tab, right-click your cluster name and select Deploy OVF Template.
-
On the Select an OVF tab, specify the name of the RHCOS OVA file that you downloaded.
-
On the Select a name and folder tab, set a Virtual machine name for your template, such as
Template-RHCOS. Click the name of your vSphere cluster and select the folder you created in the previous step. -
On the Select a compute resource tab, click the name of your vSphere cluster.
-
On the Select storage tab, configure the storage options for your VM.
-
Select Thin Provision or Thick Provision, based on your storage preferences.
-
Select the datastore that you specified in your
install-config.yamlfile. -
If you want to encrypt your virtual machines, select Encrypt this virtual machine. See the section titled "Requirements for encrypting virtual machines" for more information.
-
-
On the Select network tab, specify the network that you configured for the cluster, if available.
-
When creating the OVF template, do not specify values on the Customize template tab or configure the template any further.
Do not start the original VM template. The VM template must remain off and must be cloned for new RHCOS machines. Starting the VM template configures the VM template as a VM on the platform, which prevents it from being used as a template that compute machine sets can apply configurations to.
-
-
Optional: Update the configured virtual hardware version in the VM template, if necessary. Follow Upgrading a virtual machine to the latest hardware version in the VMware documentation for more information.
It is recommended that you update the hardware version of the VM template to version 15 before creating VMs from it, if necessary. Using hardware version 13 for your cluster nodes running on vSphere is now deprecated. If your imported template defaults to hardware version 13, you must ensure that your ESXi host is on 6.7U3 or later before upgrading the VM template to hardware version 15. If your vSphere version is less than 6.7U3, you can skip this upgrade step; however, a future version of OpenShift Container Platform is scheduled to remove support for hardware version 13 and vSphere versions less than 6.7U3.
-
After the template deploys, deploy a VM for a machine in the cluster.
-
Right-click the template name and click Clone → Clone to Virtual Machine.
-
On the Select a name and folder tab, specify a name for the VM. You might include the machine type in the name, such as
control-plane-0orcompute-1.Ensure that all virtual machine names across a vSphere installation are unique.
-
On the Select a name and folder tab, select the name of the folder that you created for the cluster.
-
On the Select a compute resource tab, select the name of a host in your datacenter.
-
On the Select clone options tab, select Customize this virtual machine’s hardware.
-
On the Customize hardware tab, click Advanced Parameters.
The following configuration suggestions are for example purposes only. As a cluster administrator, you must configure resources according to the resource demands placed on your cluster. To best manage cluster resources, consider creating a resource pool from the cluster’s root resource pool.
-
Optional: Override default DHCP networking in vSphere. To enable static IP networking:
-
Set your static IP configuration:
Example command$ export IPCFG="ip=<ip>::<gateway>:<netmask>:<hostname>:<iface>:none nameserver=srv1 [nameserver=srv2 [nameserver=srv3 [...]]]"Example command$ export IPCFG="ip=192.168.100.101::192.168.100.254:255.255.255.0:::none nameserver=8.8.8.8" -
Set the
guestinfo.afterburn.initrd.network-kargsproperty before you boot a VM from an OVA in vSphere:Example command$ govc vm.change -vm "<vm_name>" -e "guestinfo.afterburn.initrd.network-kargs=${IPCFG}"
-
-
Add the following configuration parameter names and values by specifying data in the Attribute and Values fields. Ensure that you select the Add button for each parameter that you create.
-
guestinfo.ignition.config.data: Locate the base-64 encoded files that you created previously in this procedure, and paste the contents of the base64-encoded Ignition config file for this machine type. -
guestinfo.ignition.config.data.encoding: Specifybase64. -
disk.EnableUUID: SpecifyTRUE. -
stealclock.enable: If this parameter was not defined, add it and specifyTRUE. -
Create a child resource pool from the cluster’s root resource pool. Perform resource allocation in this child resource pool.
-
-
-
In the Virtual Hardware panel of the Customize hardware tab, modify the specified values as required. Ensure that the amount of RAM, CPU, and disk storage meets the minimum requirements for the machine type.
-
Complete the remaining configuration steps. On clicking the Finish button, you have completed the cloning operation.
-
From the Virtual Machines tab, right-click on your VM and then select Power → Power On.
-
Check the console output to verify that Ignition ran.
Example commandIgnition: ran on 2022/03/14 14:48:33 UTC (this boot) Ignition: user-provided config was applied
-
Next steps
-
Create the rest of the machines for your cluster by following the preceding steps for each machine.
You must create the bootstrap and control plane machines at this time. Because some pods are deployed on compute machines by default, also create at least two compute machines before you install the cluster.
Adding more compute machines to a cluster in vSphere
You can add more compute machines to a user-provisioned OpenShift Container Platform cluster on VMware vSphere.
After your vSphere template deploys in your OpenShift Container Platform cluster, you can deploy a virtual machine (VM) for a machine in that cluster.
Prerequisites
-
Obtain the base64-encoded Ignition file for your compute machines.
-
You have access to the vSphere template that you created for your cluster.
Procedure
-
Right-click the template’s name and click Clone → Clone to Virtual Machine.
-
On the Select a name and folder tab, specify a name for the VM. You might include the machine type in the name, such as
compute-1.Ensure that all virtual machine names across a vSphere installation are unique.
-
On the Select a name and folder tab, select the name of the folder that you created for the cluster.
-
On the Select a compute resource tab, select the name of a host in your datacenter.
-
On the Select storage tab, select storage for your configuration and disk files.
-
On the Select clone options tab, select Customize this virtual machine’s hardware.
-
On the Customize hardware tab, click Advanced Parameters.
-
Add the following configuration parameter names and values by specifying data in the Attribute and Values fields. Ensure that you select the Add button for each parameter that you create.
-
guestinfo.ignition.config.data: Paste the contents of the base64-encoded compute Ignition config file for this machine type. -
guestinfo.ignition.config.data.encoding: Specifybase64. -
disk.EnableUUID: SpecifyTRUE.
-
-
-
In the Virtual Hardware panel of the Customize hardware tab, modify the specified values as required. Ensure that the amount of RAM, CPU, and disk storage meets the minimum requirements for the machine type. If many networks exist, select Add New Device > Network Adapter, and then enter your network information in the fields provided by the New Network menu item.
-
Complete the remaining configuration steps. On clicking the Finish button, you have completed the cloning operation.
-
From the Virtual Machines tab, right-click on your VM and then select Power → Power On.
Next steps
-
Continue to create more compute machines for your cluster.
Disk partitioning
In most cases, data partitions are originally created by installing RHCOS, rather than by installing another operating system. In such cases, the OpenShift Container Platform installer should be allowed to configure your disk partitions.
However, there are two cases where you might want to intervene to override the default partitioning when installing an OpenShift Container Platform node:
-
Create separate partitions: For greenfield installations on an empty disk, you might want to add separate storage to a partition. This is officially supported for making
/varor a subdirectory of/var, such as/var/lib/etcd, a separate partition, but not both.For disk sizes larger than 100GB, and especially disk sizes larger than 1TB, create a separate
/varpartition. See "Creating a separate/varpartition" and this Red Hat Knowledgebase article for more information.Kubernetes supports only two file system partitions. If you add more than one partition to the original configuration, Kubernetes cannot monitor all of them.
-
Retain existing partitions: For a brownfield installation where you are reinstalling OpenShift Container Platform on an existing node and want to retain data partitions installed from your previous operating system, there are both boot arguments and options to
coreos-installerthat allow you to retain existing data partitions.
Creating a separate /var partition
In general, disk partitioning for OpenShift Container Platform should be left to the installer. However, there are cases where you might want to create separate partitions in a part of the filesystem that you expect to grow.
OpenShift Container Platform supports the addition of a single partition to attach
storage to either the /var partition or a subdirectory of /var.
For example:
-
/var/lib/containers: Holds container-related content that can grow as more images and containers are added to a system. -
/var/lib/etcd: Holds data that you might want to keep separate for purposes such as performance optimization of etcd storage. -
/var: Holds data that you might want to keep separate for purposes such as auditing.For disk sizes larger than 100GB, and especially larger than 1TB, create a separate
/varpartition.
Storing the contents of a /var directory separately makes it easier to grow storage for those areas as needed and reinstall OpenShift Container Platform at a later date and keep that data intact. With this method, you will not have to pull all your containers again, nor will you have to copy massive log files when you update systems.
Because /var must be in place before a fresh installation of
Red Hat Enterprise Linux CoreOS (RHCOS), the following procedure sets up the separate /var partition
by creating a machine config manifest that is inserted during the openshift-install
preparation phases of an OpenShift Container Platform installation.
Procedure
-
Create a directory to hold the OpenShift Container Platform installation files:
$ mkdir $HOME/clusterconfig -
Run
openshift-installto create a set of files in themanifestandopenshiftsubdirectories. Answer the system questions as you are prompted:$ openshift-install create manifests --dir $HOME/clusterconfig ? SSH Public Key ... $ ls $HOME/clusterconfig/openshift/ 99_kubeadmin-password-secret.yaml 99_openshift-cluster-api_master-machines-0.yaml 99_openshift-cluster-api_master-machines-1.yaml 99_openshift-cluster-api_master-machines-2.yaml ... -
Create a Butane config that configures the additional partition. For example, name the file
$HOME/clusterconfig/98-var-partition.bu, change the disk device name to the name of the storage device on theworkersystems, and set the storage size as appropriate. This example places the/vardirectory on a separate partition:variant: openshift version: 4.13.0 metadata: labels: machineconfiguration.openshift.io/role: worker name: 98-var-partition storage: disks: - device: /dev/disk/by-id/<device_name> (1) partitions: - label: var start_mib: <partition_start_offset> (2) size_mib: <partition_size> (3) number: 5 filesystems: - device: /dev/disk/by-partlabel/var path: /var format: xfs mount_options: [defaults, prjquota] (4) with_mount_unit: true1 The storage device name of the disk that you want to partition. 2 When adding a data partition to the boot disk, a minimum value of 25000 mebibytes is recommended. The root file system is automatically resized to fill all available space up to the specified offset. If no value is specified, or if the specified value is smaller than the recommended minimum, the resulting root file system will be too small, and future reinstalls of RHCOS might overwrite the beginning of the data partition. 3 The size of the data partition in mebibytes. 4 The prjquotamount option must be enabled for filesystems used for container storage.When creating a separate
/varpartition, you cannot use different instance types for worker nodes, if the different instance types do not have the same device name. -
Create a manifest from the Butane config and save it to the
clusterconfig/openshiftdirectory. For example, run the following command:$ butane $HOME/clusterconfig/98-var-partition.bu -o $HOME/clusterconfig/openshift/98-var-partition.yaml -
Run
openshift-installagain to create Ignition configs from a set of files in themanifestandopenshiftsubdirectories:$ openshift-install create ignition-configs --dir $HOME/clusterconfig $ ls $HOME/clusterconfig/ auth bootstrap.ign master.ign metadata.json worker.ign
Now you can use the Ignition config files as input to the vSphere installation procedures to install Red Hat Enterprise Linux CoreOS (RHCOS) systems.
Waiting for the bootstrap process to complete
The OpenShift Container Platform bootstrap process begins after the cluster nodes first boot into the persistent RHCOS environment that has been installed to disk. The configuration information provided through the Ignition config files is used to initialize the bootstrap process and install OpenShift Container Platform on the machines. You must wait for the bootstrap process to complete.
Prerequisites
-
You have created the Ignition config files for your cluster.
-
You have configured suitable network, DNS and load balancing infrastructure.
-
You have obtained the installation program and generated the Ignition config files for your cluster.
-
You installed RHCOS on your cluster machines and provided the Ignition config files that the OpenShift Container Platform installation program generated.
Procedure
-
Monitor the bootstrap process:
$ ./openshift-install --dir <installation_directory> wait-for bootstrap-complete \ (1) --log-level=info (2)1 For <installation_directory>, specify the path to the directory that you stored the installation files in.2 To view different installation details, specify warn,debug, orerrorinstead ofinfo.Example outputINFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443... INFO API v1.26.0 up INFO Waiting up to 30m0s for bootstrapping to complete... INFO It is now safe to remove the bootstrap resourcesThe command succeeds when the Kubernetes API server signals that it has been bootstrapped on the control plane machines.
-
After the bootstrap process is complete, remove the bootstrap machine from the load balancer.
You must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the bootstrap machine itself.
Logging in to the cluster by using the CLI
You can log in to your cluster as a default system user by exporting the cluster kubeconfig file.
The kubeconfig file contains information about the cluster that is used by the CLI to connect a client to the correct cluster and API server.
The file is specific to a cluster and is created during OpenShift Container Platform installation.
Prerequisites
-
You deployed an OpenShift Container Platform cluster.
-
You installed the
ocCLI.
Procedure
-
Export the
kubeadmincredentials:$ export KUBECONFIG=<installation_directory>/auth/kubeconfig (1)1 For <installation_directory>, specify the path to the directory that you stored the installation files in. -
Verify you can run
occommands successfully using the exported configuration:$ oc whoamiExample outputsystem:admin
Approving the certificate signing requests for your machines
When you add machines to a cluster, two pending certificate signing requests (CSRs) are generated for each machine that you added. You must confirm that these CSRs are approved or, if necessary, approve them yourself. The client requests must be approved first, followed by the server requests.
Prerequisites
-
You added machines to your cluster.
Procedure
-
Confirm that the cluster recognizes the machines:
$ oc get nodesExample outputNAME STATUS ROLES AGE VERSION master-0 Ready master 63m v1.26.0 master-1 Ready master 63m v1.26.0 master-2 Ready master 64m v1.26.0The output lists all of the machines that you created.
The preceding output might not include the compute nodes, also known as worker nodes, until some CSRs are approved.
-
Review the pending CSRs and ensure that you see the client requests with the
PendingorApprovedstatus for each machine that you added to the cluster:$ oc get csrExample outputNAME AGE REQUESTOR CONDITION csr-8b2br 15m system:serviceaccount:openshift-machine-config-operator:node-bootstrapper Pending csr-8vnps 15m system:serviceaccount:openshift-machine-config-operator:node-bootstrapper Pending ...In this example, two machines are joining the cluster. You might see more approved CSRs in the list.
-
If the CSRs were not approved, after all of the pending CSRs for the machines you added are in
Pendingstatus, approve the CSRs for your cluster machines:Because the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. After the client CSR is approved, the Kubelet creates a secondary CSR for the serving certificate, which requires manual approval. Then, subsequent serving certificate renewal requests are automatically approved by the
machine-approverif the Kubelet requests a new certificate with identical parameters.For clusters running on platforms that are not machine API enabled, such as bare metal and other user-provisioned infrastructure, you must implement a method of automatically approving the kubelet serving certificate requests (CSRs). If a request is not approved, then the
oc exec,oc rsh, andoc logscommands cannot succeed, because a serving certificate is required when the API server connects to the kubelet. Any operation that contacts the Kubelet endpoint requires this certificate approval to be in place. The method must watch for new CSRs, confirm that the CSR was submitted by thenode-bootstrapperservice account in thesystem:nodeorsystem:admingroups, and confirm the identity of the node.-
To approve them individually, run the following command for each valid CSR:
$ oc adm certificate approve <csr_name> (1)1 <csr_name>is the name of a CSR from the list of current CSRs. -
To approve all pending CSRs, run the following command:
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs --no-run-if-empty oc adm certificate approveSome Operators might not become available until some CSRs are approved.
-
-
Now that your client requests are approved, you must review the server requests for each machine that you added to the cluster:
$ oc get csrExample outputNAME AGE REQUESTOR CONDITION csr-bfd72 5m26s system:node:ip-10-0-50-126.us-east-2.compute.internal Pending csr-c57lv 5m26s system:node:ip-10-0-95-157.us-east-2.compute.internal Pending ... -
If the remaining CSRs are not approved, and are in the
Pendingstatus, approve the CSRs for your cluster machines:-
To approve them individually, run the following command for each valid CSR:
$ oc adm certificate approve <csr_name> (1)1 <csr_name>is the name of a CSR from the list of current CSRs. -
To approve all pending CSRs, run the following command:
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
-
-
After all client and server CSRs have been approved, the machines have the
Readystatus. Verify this by running the following command:$ oc get nodesExample outputNAME STATUS ROLES AGE VERSION master-0 Ready master 73m v1.26.0 master-1 Ready master 73m v1.26.0 master-2 Ready master 74m v1.26.0 worker-0 Ready worker 11m v1.26.0 worker-1 Ready worker 11m v1.26.0It can take a few minutes after approval of the server CSRs for the machines to transition to the
Readystatus.
Additional information
-
For more information on CSRs, see Certificate Signing Requests.
Initial Operator configuration
After the control plane initializes, you must immediately configure some Operators so that they all become available.
Prerequisites
-
Your control plane has initialized.
Procedure
-
Watch the cluster components come online:
$ watch -n5 oc get clusteroperatorsExample outputNAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE authentication 4.13.0 True False False 19m baremetal 4.13.0 True False False 37m cloud-credential 4.13.0 True False False 40m cluster-autoscaler 4.13.0 True False False 37m config-operator 4.13.0 True False False 38m console 4.13.0 True False False 26m csi-snapshot-controller 4.13.0 True False False 37m dns 4.13.0 True False False 37m etcd 4.13.0 True False False 36m image-registry 4.13.0 True False False 31m ingress 4.13.0 True False False 30m insights 4.13.0 True False False 31m kube-apiserver 4.13.0 True False False 26m kube-controller-manager 4.13.0 True False False 36m kube-scheduler 4.13.0 True False False 36m kube-storage-version-migrator 4.13.0 True False False 37m machine-api 4.13.0 True False False 29m machine-approver 4.13.0 True False False 37m machine-config 4.13.0 True False False 36m marketplace 4.13.0 True False False 37m monitoring 4.13.0 True False False 29m network 4.13.0 True False False 38m node-tuning 4.13.0 True False False 37m openshift-apiserver 4.13.0 True False False 32m openshift-controller-manager 4.13.0 True False False 30m openshift-samples 4.13.0 True False False 32m operator-lifecycle-manager 4.13.0 True False False 37m operator-lifecycle-manager-catalog 4.13.0 True False False 37m operator-lifecycle-manager-packageserver 4.13.0 True False False 32m service-ca 4.13.0 True False False 38m storage 4.13.0 True False False 37m -
Configure the Operators that are not available.
Disabling the default OperatorHub catalog sources
Operator catalogs that source content provided by Red Hat and community projects are configured for OperatorHub by default during an OpenShift Container Platform installation. In a restricted network environment, you must disable the default catalogs as a cluster administrator.
Procedure
-
Disable the sources for the default catalogs by adding
disableAllDefaultSources: trueto theOperatorHubobject:$ oc patch OperatorHub cluster --type json \ -p '[{"op": "add", "path": "/spec/disableAllDefaultSources", "value": true}]'
|
Alternatively, you can use the web console to manage catalog sources. From the Administration → Cluster Settings → Configuration → OperatorHub page, click the Sources tab, where you can create, update, delete, disable, and enable individual sources. |
Image registry storage configuration
The Image Registry Operator is not initially available for platforms that do not provide default storage. After installation, you must configure your registry to use storage so that the Registry Operator is made available.
Instructions are shown for configuring a persistent volume, which is required for production clusters. Where applicable, instructions are shown for configuring an empty directory as the storage location, which is available for only non-production clusters.
Additional instructions are provided for allowing the image registry to use block storage types by using the Recreate rollout strategy during upgrades.
Configuring registry storage for VMware vSphere
As a cluster administrator, following installation you must configure your registry to use storage.
Prerequisites
-
Cluster administrator permissions.
-
A cluster on VMware vSphere.
-
Persistent storage provisioned for your cluster, such as Red Hat OpenShift Data Foundation.
OpenShift Container Platform supports
ReadWriteOnceaccess for image registry storage when you have only one replica.ReadWriteOnceaccess also requires that the registry uses theRecreaterollout strategy. To deploy an image registry that supports high availability with two or more replicas,ReadWriteManyaccess is required. -
Must have "100Gi" capacity.
|
Testing shows issues with using the NFS server on RHEL as storage backend for core services. This includes the OpenShift Container Registry and Quay, Prometheus for monitoring storage, and Elasticsearch for logging storage. Therefore, using RHEL NFS to back PVs used by core services is not recommended. Other NFS implementations on the marketplace might not have these issues. Contact the individual NFS implementation vendor for more information on any testing that was possibly completed against these OpenShift Container Platform core components. |
Procedure
-
To configure your registry to use storage, change the
spec.storage.pvcin theconfigs.imageregistry/clusterresource.When you use shared storage, review your security settings to prevent outside access.
-
Verify that you do not have a registry pod:
$ oc get pod -n openshift-image-registry -l docker-registry=defaultExample outputNo resourses found in openshift-image-registry namespaceIf you do have a registry pod in your output, you do not need to continue with this procedure.
-
Check the registry configuration:
$ oc edit configs.imageregistry.operator.openshift.ioExample outputstorage: pvc: claim: (1)1 Leave the claimfield blank to allow the automatic creation of animage-registry-storagepersistent volume claim (PVC). The PVC is generated based on the default storage class. However, be aware that the default storage class might provide ReadWriteOnce (RWO) volumes, such as a RADOS Block Device (RBD), which can cause issues when you replicate to more than one replica. -
Check the
clusteroperatorstatus:$ oc get clusteroperator image-registryExample outputNAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE MESSAGE image-registry 4.7 True False False 6h50m
Configuring storage for the image registry in non-production clusters
You must configure storage for the Image Registry Operator. For non-production clusters, you can set the image registry to an empty directory. If you do so, all images are lost if you restart the registry.
Procedure
-
To set the image registry storage to an empty directory:
$ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"storage":{"emptyDir":{}}}}'Configure this option for only non-production clusters.
If you run this command before the Image Registry Operator initializes its components, the
oc patchcommand fails with the following error:Error from server (NotFound): configs.imageregistry.operator.openshift.io "cluster" not foundWait a few minutes and run the command again.
Configuring block registry storage for VMware vSphere
To allow the image registry to use block storage types such as vSphere Virtual Machine Disk (VMDK) during upgrades as a cluster administrator, you can use the Recreate rollout strategy.
|
Block storage volumes are supported but not recommended for use with image registry on production clusters. An installation where the registry is configured on block storage is not highly available because the registry cannot have more than one replica. |
Procedure
-
Enter the following command to set the image registry storage as a block storage type, patch the registry so that it uses the
Recreaterollout strategy, and runs with only1replica:$ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}' -
Provision the PV for the block storage device, and create a PVC for that volume. The requested block volume uses the ReadWriteOnce (RWO) access mode.
-
Create a
pvc.yamlfile with the following contents to define a VMware vSpherePersistentVolumeClaimobject:kind: PersistentVolumeClaim apiVersion: v1 metadata: name: image-registry-storage (1) namespace: openshift-image-registry (2) spec: accessModes: - ReadWriteOnce (3) resources: requests: storage: 100Gi (4)1 A unique name that represents the PersistentVolumeClaimobject.2 The namespace for the PersistentVolumeClaimobject, which isopenshift-image-registry.3 The access mode of the persistent volume claim. With ReadWriteOnce, the volume can be mounted with read and write permissions by a single node.4 The size of the persistent volume claim. -
Enter the following command to create the
PersistentVolumeClaimobject from the file:$ oc create -f pvc.yaml -n openshift-image-registry
-
-
Enter the following command to edit the registry configuration so that it references the correct PVC:
$ oc edit config.imageregistry.operator.openshift.io -o yamlExample outputstorage: pvc: claim: (1)1 By creating a custom PVC, you can leave the claimfield blank for the default automatic creation of animage-registry-storagePVC.
For instructions about configuring registry storage so that it references the correct PVC, see Configuring registry storage for VMware vSphere.
Completing installation on user-provisioned infrastructure
After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.
Prerequisites
-
Your control plane has initialized.
-
You have completed the initial Operator configuration.
Procedure
-
Confirm that all the cluster components are online with the following command:
$ watch -n5 oc get clusteroperatorsExample outputNAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE authentication 4.13.0 True False False 19m baremetal 4.13.0 True False False 37m cloud-credential 4.13.0 True False False 40m cluster-autoscaler 4.13.0 True False False 37m config-operator 4.13.0 True False False 38m console 4.13.0 True False False 26m csi-snapshot-controller 4.13.0 True False False 37m dns 4.13.0 True False False 37m etcd 4.13.0 True False False 36m image-registry 4.13.0 True False False 31m ingress 4.13.0 True False False 30m insights 4.13.0 True False False 31m kube-apiserver 4.13.0 True False False 26m kube-controller-manager 4.13.0 True False False 36m kube-scheduler 4.13.0 True False False 36m kube-storage-version-migrator 4.13.0 True False False 37m machine-api 4.13.0 True False False 29m machine-approver 4.13.0 True False False 37m machine-config 4.13.0 True False False 36m marketplace 4.13.0 True False False 37m monitoring 4.13.0 True False False 29m network 4.13.0 True False False 38m node-tuning 4.13.0 True False False 37m openshift-apiserver 4.13.0 True False False 32m openshift-controller-manager 4.13.0 True False False 30m openshift-samples 4.13.0 True False False 32m operator-lifecycle-manager 4.13.0 True False False 37m operator-lifecycle-manager-catalog 4.13.0 True False False 37m operator-lifecycle-manager-packageserver 4.13.0 True False False 32m service-ca 4.13.0 True False False 38m storage 4.13.0 True False False 37mAlternatively, the following command notifies you when all of the clusters are available. It also retrieves and displays credentials:
$ ./openshift-install --dir <installation_directory> wait-for install-complete (1)1 For <installation_directory>, specify the path to the directory that you stored the installation files in.Example outputINFO Waiting up to 30m0s for the cluster to initialize...The command succeeds when the Cluster Version Operator finishes deploying the OpenShift Container Platform cluster from Kubernetes API server.
-
The Ignition config files that the installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending
node-bootstrappercertificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information. -
It is recommended that you use Ignition config files within 12 hours after they are generated because the 24-hour certificate rotates from 16 to 22 hours after the cluster is installed. By using the Ignition config files within 12 hours, you can avoid installation failure if the certificate update runs during installation.
-
-
Confirm that the Kubernetes API server is communicating with the pods.
-
To view a list of all pods, use the following command:
$ oc get pods --all-namespacesExample outputNAMESPACE NAME READY STATUS RESTARTS AGE openshift-apiserver-operator openshift-apiserver-operator-85cb746d55-zqhs8 1/1 Running 1 9m openshift-apiserver apiserver-67b9g 1/1 Running 0 3m openshift-apiserver apiserver-ljcmx 1/1 Running 0 1m openshift-apiserver apiserver-z25h4 1/1 Running 0 2m openshift-authentication-operator authentication-operator-69d5d8bf84-vh2n8 1/1 Running 0 5m ... -
View the logs for a pod that is listed in the output of the previous command by using the following command:
$ oc logs <pod_name> -n <namespace> (1)1 Specify the pod name and namespace, as shown in the output of the previous command. If the pod logs display, the Kubernetes API server can communicate with the cluster machines.
-
-
For an installation with Fibre Channel Protocol (FCP), additional steps are required to enable multipathing. Do not enable multipathing during installation.
See "Enabling multipathing with kernel arguments on RHCOS" in the Post-installation machine configuration tasks documentation for more information.
-
Register your cluster on the Cluster registration page.
You can add extra compute machines after the cluster installation is completed by following Adding compute machines to vSphere.
Backing up VMware vSphere volumes
OpenShift Container Platform provisions new volumes as independent persistent disks to freely attach and detach the volume on any node in the cluster. As a consequence, it is not possible to back up volumes that use snapshots, or to restore volumes from snapshots. See Snapshot Limitations for more information.
Procedure
To create a backup of persistent volumes:
-
Stop the application that is using the persistent volume.
-
Clone the persistent volume.
-
Restart the application.
-
Create a backup of the cloned volume.
-
Delete the cloned volume.
Telemetry access for OpenShift Container Platform
In OpenShift Container Platform 4.13, the Telemetry service, which runs by default to provide metrics about cluster health and the success of updates, requires internet access. If your cluster is connected to the internet, Telemetry runs automatically, and your cluster is registered to OpenShift Cluster Manager Hybrid Cloud Console.
After you confirm that your OpenShift Cluster Manager Hybrid Cloud Console inventory is correct, either maintained automatically by Telemetry or manually by using OpenShift Cluster Manager, use subscription watch to track your OpenShift Container Platform subscriptions at the account or multi-cluster level.
Additional resources
-
See About remote health monitoring for more information about the Telemetry service
Next steps
-
Configure image streams for the Cluster Samples Operator and the
must-gathertool. -
Learn how to use Operator Lifecycle Manager (OLM) on restricted networks.
-
If the mirror registry that you used to install your cluster has a trusted CA, add it to the cluster by configuring additional trust stores.
-
If necessary, you can opt out of remote health reporting.
-
Optional: View the events from the vSphere Problem Detector Operator to determine if the cluster has permission or storage configuration issues.