1 1 physical core provides 2 vCPUs when hyper-threading is enabled. 1 physical core provides 1 vCPU when hyper-threading is not enabled.
In OpenShift Container Platform version 4.4, you can install a cluster on bare metal infrastructure that you provision in a restricted network.
While you might be able to follow this procedure to deploy a cluster on virtualized or cloud environments, you must be aware of additional considerations for non-bare metal platforms. Review the information in the guidelines for deploying OpenShift Container Platform on non-tested platforms before you attempt to install an OpenShift Container Platform cluster in such an environment. |
Create a registry on your mirror host and obtain the imageContentSources
data 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. |
Provision persistent storage for your cluster. To deploy a private image registry, your storage must provide ReadWriteMany access modes.
Review details about the OpenShift Container Platform installation and update processes.
If you use a firewall and plan to use telemetry, you must configure 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. |
In OpenShift Container Platform 4.4, you can perform an installation that does not require an active connection to the Internet to obtain software components. You complete an installation in a restricted network on only infrastructure that you provision, not infrastructure that the installation program provisions, so your platform selection is limited.
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 IAM service, require Internet access, so you might still require Internet access. Depending on your network, you might require less Internet access for an installation on bare metal hardware or on VMware vSphere.
To complete a restricted network installation, you must create a registry that mirrors the contents of the OpenShift Container Platform 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.
Restricted network installations always use user-provisioned infrastructure. 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. Completing this test installation might make it easier to isolate and troubleshoot any issues that might arise during your installation in a restricted network. |
Clusters in restricted networks have the following additional limitations and restrictions:
The ClusterVersion
status includes an Unable to retrieve available updates
error.
By default, you cannot use the contents of the Developer Catalog because you cannot access the required image stream tags.
In OpenShift Container Platform 4.4, you require access to the Internet to obtain the images that are necessary to install your cluster. The Telemetry service, which runs by default to provide metrics about cluster health and the success of updates, also requires Internet access. If your cluster is connected to the Internet, Telemetry runs automatically, and your cluster is registered to the Red Hat OpenShift Cluster Manager (OCM).
Once you confirm that your Red Hat OpenShift Cluster Manager inventory is correct, either maintained automatically by Telemetry or manually using OCM, use subscription watch to track your OpenShift Container Platform subscriptions at the account or multi-cluster level.
You must have Internet access to:
Access the Red Hat OpenShift Cluster Manager page 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.
If your cluster cannot have direct Internet access, you can perform a restricted network installation on some types of infrastructure that you provision. During that process, you download the content that is required and use it to populate a mirror registry with the packages that you need to install a cluster and generate the installation program. With some installation types, the environment that you install your cluster in will not require Internet access. Before you update the cluster, you update the content of the mirror registry. |
For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.
The smallest OpenShift Container Platform clusters require the following hosts:
One temporary bootstrap machine
Three control plane, or master, machines
At least two compute machines, which are also known as worker machines
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. |
To maintain high availability of your cluster, use separate physical hosts for these cluster machines. |
The bootstrap, control plane, and compute machines must use the Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system.
Note that RHCOS is based on Red Hat Enterprise Linux 8 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.
All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs
during boot to fetch Ignition config files from the Machine Config Server.
During the initial boot, the machines require either a DHCP server
or that static IP addresses be set in order to establish a network
connection to download their Ignition config files.
Each cluster machine must meet the following minimum requirements:
Machine | Operating System | vCPU1 | Virtual RAM | Storage |
---|---|---|---|---|
Bootstrap |
RHCOS |
4 |
16 GB |
120 GB |
Control plane |
RHCOS |
4 |
16 GB |
120 GB |
Compute |
RHCOS or RHEL 7.6 |
2 |
8 GB |
120 GB |
1 1 physical core provides 2 vCPUs when hyper-threading is enabled. 1 physical core provides 1 vCPU when hyper-threading is not enabled. |
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.
Before you deploy an OpenShift Container Platform cluster that uses user-provisioned infrastructure, you must create the underlying infrastructure.
Review the OpenShift Container Platform 4.x Tested Integrations page before you create the supporting infrastructure for your cluster.
Configure DHCP or set static IP addresses on each node.
Provision the required load balancers.
Configure the ports for your machines.
Configure DNS.
Ensure network connectivity.
All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs
during boot
to fetch Ignition config from the machine config server.
During the initial boot, the machines require either a DHCP server or that static IP addresses be set on each host in the cluster in order to establish a network connection, which allows them to download their Ignition config files.
It is recommended to use the DHCP server to manage the machines for the cluster long-term. Ensure that the DHCP server is configured to provide persistent IP addresses and host names to the cluster machines.
The Kubernetes API server, which runs on each master node after a successful cluster installation, 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.
You must configure the network connectivity between machines to allow cluster components to communicate. Each machine must be able to resolve the host names of all other machines in the cluster.
Protocol | Port | Description |
---|---|---|
ICMP |
N/A |
Network reachability tests |
TCP |
|
Host level services, including the node exporter on ports |
|
The default ports that Kubernetes reserves |
|
|
openshift-sdn |
|
UDP |
|
VXLAN and Geneve |
|
VXLAN and Geneve |
|
|
Host level services, including the node exporter on ports |
|
TCP/UDP |
|
Kubernetes node port |
Protocol | Port | Description |
---|---|---|
TCP |
|
etcd server, peer, and metrics ports |
|
Kubernetes API |
The infrastructure that you provision for your cluster must meet the following network topology requirements.
OpenShift Container Platform requires all nodes to have internet access to pull images for platform containers and provide telemetry data to Red Hat. |
Before you install OpenShift Container Platform, you must provision two load balancers that 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, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the API routes.
A stateless load balancing algorithm. The options vary based on the load balancer implementation.
Session persistence is not required for the API load balancer to function properly. |
Configure the following ports on both the front and back of the load balancers:
Port | Back-end machines (pool members) | Internal | External | Description |
---|---|---|---|---|
|
Bootstrap 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 |
X |
X |
Kubernetes API server |
|
Bootstrap 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 |
Application Ingress load balancer: Provides an Ingress point for application traffic flowing in from outside the cluster. Configure the following conditions:
Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the Ingress routes.
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.
Configure the following ports on both the front and back of the load balancers:
Port | Back-end machines (pool members) | Internal | External | Description |
---|---|---|---|---|
|
The machines that run the Ingress router pods, compute, or worker, by default. |
X |
X |
HTTPS traffic |
|
The machines that run the Ingress router pods, compute, or worker, by default. |
X |
X |
HTTP traffic |
If the true IP address of the client can be seen by the load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption. |
A working configuration for the Ingress router is required for an OpenShift Container Platform cluster. You must configure the Ingress router after the control plane initializes. |
DNS is used for name resolution and reverse name resolution. 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 host name for all the nodes. Additionally, the reverse records are used to generate the certificate signing requests (CSR) that OpenShift Container Platform needs to operate.
The following DNS records are required for an OpenShift Container Platform cluster that uses
user-provisioned infrastructure. In each record, <cluster_name>
is the cluster
name and <base_domain>
is the cluster 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 |
|
Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster. |
|
|
Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable from all the nodes within the cluster.
|
||
Routes |
|
Add a wildcard DNS A/AAAA or CNAME record that refers to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster. |
|
Bootstrap |
|
Add 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. |
|
Master hosts |
|
Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the master nodes. These records must be resolvable by the nodes within the cluster. |
|
Worker hosts |
|
Add 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. |
You can use the |
The following example of a BIND zone file shows sample A records for name resolution. The purpose of the example is to show the records that are needed. The example is not meant to provide advice for choosing one name resolution service over another.
$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 IN A 192.168.1.5
smtp IN A 192.168.1.5
;
helper IN A 192.168.1.5
helper.ocp4 IN A 192.168.1.5
;
; The api identifies the IP of your load balancer.
api.ocp4 IN A 192.168.1.5
api-int.ocp4 IN A 192.168.1.5
;
; The wildcard also identifies the load balancer.
*.apps.ocp4 IN A 192.168.1.5
;
; Create an entry for the bootstrap host.
bootstrap.ocp4 IN A 192.168.1.96
;
; Create entries for the master hosts.
master0.ocp4 IN A 192.168.1.97
master1.ocp4 IN A 192.168.1.98
master2.ocp4 IN A 192.168.1.99
;
; Create entries for the worker hosts.
worker0.ocp4 IN A 192.168.1.11
worker1.ocp4 IN A 192.168.1.7
;
;EOF
The following example BIND zone file shows sample PTR records for reverse name resolution.
$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.
;
; The syntax is "last octet" and the host must have an FQDN
; with a trailing dot.
97 IN PTR master0.ocp4.example.com.
98 IN PTR master1.ocp4.example.com.
99 IN PTR master2.ocp4.example.com.
;
96 IN PTR bootstrap.ocp4.example.com.
;
5 IN PTR api.ocp4.ocp4.example.com.
5 IN PTR api-int.ocp4.ocp4.example.com.
;
11 IN PTR worker0.ocp4.example.com.
7 IN PTR worker1.ocp4.example.com.
;
;EOF
If you want to perform installation debugging or disaster recovery on your cluster, you must provide an SSH key to both your ssh-agent
and the installation program. You can use this key to access the bootstrap machine in a public cluster to troubleshoot installation issues.
In a production environment, you require disaster recovery and debugging. |
You can use this key to SSH into the master nodes as the user core
. When you
deploy the cluster, the key is added to the core
user’s
~/.ssh/authorized_keys
list.
You must use a local key, not one that you configured with platform-specific approaches such as AWS key pairs. |
If you do not have an SSH key that is configured for password-less authentication on your computer, 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_rsa , of the SSH key.
Do not specify an existing SSH key, as it will be overwritten. |
Running this command generates an SSH key that does not require a password in the location that you specified.
Start the ssh-agent
process as a background task:
$ eval "$(ssh-agent -s)" Agent pid 31874
Add your SSH private key to the ssh-agent
:
$ ssh-add <path>/<file_name> (1) Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
1 | Specify the path and file name for your SSH private key, such as ~/.ssh/id_rsa |
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 this key to your cluster’s machines.
For installations of OpenShift Container Platform that use user-provisioned infrastructure, you must manually generate your installation configuration file.
Obtain the OpenShift Container Platform installation program and the access token for your cluster.
Obtain the imageContentSources
section from the output of the command to
mirror the repository.
Obtain the contents of the certificate for your mirror registry.
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 following install-config.yaml
file template and save
it in the <installation_directory>
.
You must name this configuration file |
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 the additionalTrustBundle
section. In most cases, you must
provide the certificate for your mirror.
You must include the imageContentSources
section from the output of the command to
mirror the repository.
Back up the install-config.yaml
file so that you can use it to install
multiple clusters.
The |
install-config.yaml
file for bare metalYou 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.
apiVersion: v1
baseDomain: example.com (1)
compute:
- hyperthreading: Enabled (2) (3)
name: worker
replicas: 0 (4)
controlPlane:
hyperthreading: Enabled (2) (3)
name: master (3)
replicas: 3 (5)
metadata:
name: test (6)
networking:
clusterNetwork:
- cidr: 10.128.0.0/14 (7)
hostPrefix: 23 (8)
networkType: OpenShiftSDN
serviceNetwork: (9)
- 172.30.0.0/16
platform:
none: {} (10)
fips: false (11)
pullSecret: '{"auths":{"<local_registry>": {"auth": "<credentials>","email": "you@example.com"}}}' (12)
sshKey: 'ssh-ed25519 AAAA...' (13)
additionalTrustBundle: | (14)
-----BEGIN CERTIFICATE-----
ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
-----END CERTIFICATE-----
imageContentSources: (15)
- mirrors:
- <local_registry>/<local_repository_name>/release
source: quay.io/openshift-release-dev/ocp-release
- mirrors:
- <local_registry>/<local_repository_name>/release
source: registry.svc.ci.openshift.org/ocp/release
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. Although both sections
currently define a single machine pool, it is possible that future versions
of OpenShift Container Platform will support defining multiple compute pools during
installation. Only one control plane pool is used. |
||
3 | Whether to enable or disable simultaneous multithreading, or
hyperthreading . By default, simultaneous multithreading is enabled
to increase the performance of your machines' cores. You can disable it by
setting the parameter value to Disabled . If you disable simultaneous
multithreading in some cluster machines, you must disable it in all cluster
machines.
|
||
4 | 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. |
||
5 | 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. | ||
6 | The cluster name that you specified in your DNS records. | ||
7 | A block of IP addresses from which pod IP addresses are allocated. This block must not overlap with existing physical networks. These IP addresses are used for the pod network. If you need to access the pods from an external network, you must configure load balancers and routers to manage the traffic. | ||
8 | The subnet prefix length to assign to each individual node. For example, if
hostPrefix is set to 23 , then each node is assigned a /23 subnet out of
the given cidr , which allows for 510 (2^(32 - 23) - 2) pod IPs addresses. If
you are required to provide access to nodes from an external network, configure
load balancers and routers to manage the traffic. |
||
9 | The IP address pool to use for service IP addresses. You can enter only one IP address pool. If you need to access the services from an external network, configure load balancers and routers to manage the traffic. | ||
10 | You must set the platform to none . You cannot provide additional platform
configuration variables for
bare metal
infrastructure. |
||
11 | 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. | ||
12 | 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. |
||
13 | The public portion of the default SSH key for the core user in
Red Hat Enterprise Linux CoreOS (RHCOS).
|
||
14 | Provide the contents of the certificate file that you used for your mirror registry. | ||
15 | Provide the imageContentSources section from the output of the command to
mirror the repository. |
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.
For bare metal installations, if you do not assign node IP addresses from the
range that is specified in the |
An existing install-config.yaml
file.
Review the sites that your cluster requires access to and determine whether any need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. Add sites to the Proxy
object’s spec.noProxy
field to bypass the proxy if necessary.
The For installations on Amazon Web Services (AWS), Google Cloud Platform (GCP), Microsoft Azure, and Red Hat OpenStack Platform (RHOSP), the |
Edit your install-config.yaml
file and add the proxy settings. For example:
apiVersion: v1
baseDomain: my.domain.com
proxy:
httpProxy: http://<username>:<pswd>@<ip>:<port> (1)
httpsProxy: http://<username>:<pswd>@<ip>:<port> (2)
noProxy: example.com (3)
additionalTrustBundle: | (4)
-----BEGIN CERTIFICATE-----
<MY_TRUSTED_CA_CERT>
-----END CERTIFICATE-----
...
1 | A proxy URL to use for creating HTTP connections outside the cluster. The
URL scheme must be http . If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an httpProxy value. |
2 | A proxy URL to use for creating HTTPS connections outside the cluster. If
this field is not specified, then httpProxy is used for both HTTP and HTTPS
connections.
If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an httpsProxy value. |
3 | A comma-separated list of destination domain names, domains, IP addresses, or
other network CIDRs to exclude proxying. Preface a domain with . to include
all subdomains of that domain. Use * to bypass proxy for all destinations. |
4 | If provided, the installation program generates a config map that is named user-ca-bundle in
the openshift-config namespace that contains one or more additional CA
certificates that are required for proxying HTTPS connections. The Cluster Network
Operator then creates a trusted-ca-bundle config map that merges these contents
with the Red Hat Enterprise Linux CoreOS (RHCOS) trust bundle, and this config map is referenced in the Proxy
object’s trustedCA field. The additionalTrustBundle field is required unless
the proxy’s identity certificate is signed by an authority from the RHCOS trust
bundle.
If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must provide the MITM CA certificate. |
The installation program does not support the proxy |
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 |
Three-node cluster is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process. For more information about the support scope of Red Hat Technology Preview features, see https://access.redhat.com/support/offerings/techpreview/. |
You can install and run three-node clusters in OpenShift Container Platform with no workers. This provides smaller, more resource efficient clusters for cluster administrators and developers to use for deployment, development, and testing.
Edit the install-config.yaml
file to set the number of compute replicas, which are also known as worker replicas, to 0
, as shown in the following compute
stanza:
compute:
- name: worker
platform: {}
replicas: 0
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 make its machines.
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 |
Obtain the OpenShift Container Platform installation program. For a restricted network installation, these files are on your mirror host.
Create the install-config.yaml
installation configuration file.
Generate the Kubernetes manifests for the cluster:
$ ./openshift-install create manifests --dir=<installation_directory> (1) INFO Consuming Install Config from target directory WARNING Making control-plane schedulable by setting MastersSchedulable to true for Scheduler cluster settings
1 | For <installation_directory> , specify the installation directory that
contains the install-config.yaml file you created. |
Because you create your own compute machines later in the installation process, you can safely ignore this warning.
If you are running a three-node cluster, skip the following step to allow the masters to be schedulable. |
Modify the <installation_directory>/manifests/cluster-scheduler-02-config.yml
Kubernetes manifest file to prevent pods from being scheduled on the control plane machines:
Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml
file.
Locate the mastersSchedulable
parameter and set its value to False
.
Save and exit the file.
Currently, due to a Kubernetes limitation, router Pods running on control plane machines will not be reachable by the ingress load balancer. This step might not be required in a future minor version of OpenShift Container Platform. |
Obtain the Ignition config files:
$ ./openshift-install create ignition-configs --dir=<installation_directory> (1)
1 | For <installation_directory> , specify the same installation directory. |
The following files are generated in the directory:
. ├── auth │ ├── kubeadmin-password │ └── kubeconfig ├── bootstrap.ign ├── master.ign ├── metadata.json └── worker.ign
Before you install a cluster on bare metal infrastructure that you provision, you must create RHCOS machines for it to use. Follow either the steps to use an ISO image or network PXE booting to create the machines.
Before you install a cluster on bare metal infrastructure that you provision, you must create RHCOS machines for it to use. You can use an ISO image to create the machines.
Obtain the Ignition config files for your cluster.
Have access to an HTTP server that you can access from your computer and that the machines that you create can access.
Upload the control plane, compute, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files. |
Obtain the RHCOS images that are required for your preferred method of installing operating system instances from the Product Downloads page on the Red Hat customer portal or the RHCOS image mirror page.
The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image versions that match your OpenShift Container Platform version if they are available. Only use ISO images for this procedure. RHCOS qcow2 images are not supported for bare metal installs. |
You must download the ISO file and the RAW disk file. Those file names resemble the following examples:
ISO: rhcos-<version>-installer.<architecture>.iso
Compressed metal RAW: rhcos-<version>-metal.<architecture>.raw.gz
Upload either the RAW RHCOS image file to your HTTP server and note its URL.
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files. |
Use the ISO to start the RHCOS installation. Use one of the following installation options:
Burn the ISO image to a disk and boot it directly.
Use ISO redirection via a LOM interface.
After the instance boots, press the TAB
or E
key to edit the kernel command line.
Add the parameters to the kernel command line:
coreos.inst=yes coreos.inst.install_dev=sda (1) coreos.inst.image_url=<image_URL> (2) coreos.inst.ignition_url=http://example.com/config.ign (3) ip=<dhcp or static IP address> (4) (5) bond=<bonded_interface> (6)
1 | Specify the block device of the system to install to. |
2 | Specify the URL of the RAW image that you uploaded to your server. |
3 | Specify the URL of the Ignition config file for this machine type. |
4 | Set ip=dhcp or set an individual static IP address (ip= ) and DNS server (nameserver= ) on each node.
See Static IP address examples for RHCOS kernel parameters for details. |
5 | If you use multiple network interfaces or DNS servers, see Static IP address examples for RHCOS kernel parameters for details on how to configure them. |
6 | Optionally, you can bond multiple network interfaces to a single interface
using the bond= option, as described in Static IP address examples for RHCOS kernel parameters. |
Press Enter to complete the installation. After RHCOS installs, the system reboots. After the system reboots, it applies the Ignition config file that you specified.
Continue to create the machines for your cluster.
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. |
If you install Red Hat Enterprise Linux CoreOS (RHCOS) from an ISO image, you can add kernel arguments when you boot that image to configure the node’s networking. The following table describes and illustrates how to use those kernel arguments.
Description | Examples |
---|---|
To configure an IP address, either use DHCP (
|
|
Specify multiple network interfaces by specifying multiple |
|
You can combine DHCP and static IP configurations on systems with multiple network interfaces. |
|
You can provide multiple DNS servers by adding a |
|
Bonding multiple network interfaces to a single interface is optionally supported
using the
|
The syntax is:
To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example: ---- bond=bond0:em1,em2:mode=active-backup ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none ---- [IMPORTANT] ==== When using the advanced networking options, you could encounter issues during the first boot of RHCOS where the statically configured address is not present or not activated properly. In such cases, you might need to manually reboot the RHCOS machine to workaround this problem. In newer versions of RHCOS, this issue is resolved. See BZ#1902584 for additional details. ==== |
Before you install a cluster on bare metal infrastructure that you provision, you must create RHCOS machines for it to use. You can use PXE or iPXE booting to create the machines.
Obtain the Ignition config files for your cluster.
Familiarity configuring the necessary DHCP, TFTP, and HTTP services for providing PXE or iPXE infrastructure.
Have access to an HTTP server and TFTP server that you can access from your computer.
Upload the master, worker, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files. |
Obtain the compressed metal RAW image, kernel
and initramfs
files from the
Product Downloads page on the Red
Hat customer portal or the
RHCOS image mirror
page.
The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image versions that match your OpenShift Container Platform version if they are available. Only use RAW images for this procedure. RHCOS qcow2 images are not supported for bare metal installs. |
The file names contain the OpenShift Container Platform version number. They resemble the following examples:
Compressed metal RAW image: rhcos-<version>-<architecture>-metal.<architecture>.raw.gz
kernel
: rhcos-<version>-<architecture>-installer-kernel-<architecture>
initramfs
: rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img
Upload the RAW image to your HTTP server.
Upload the additional files that are required for your booting method:
For traditional PXE, upload the kernel
and initramfs
files to your TFTP server.
For iPXE, upload the kernel
and initramfs
files to your HTTP server.
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files. |
Configure the network boot infrastructure so that the machines boot from their local disks after RHCOS is installed on them.
Configure PXE or iPXE installation for the RHCOS images.
Modify one of the following example menu entries for your environment and verify that the image and Ignition files are properly accessible:
For PXE:
DEFAULT pxeboot TIMEOUT 20 PROMPT 0 LABEL pxeboot KERNEL rhcos-<version>-<architecture>-installer-kernel-<architecture> (1) APPEND ip=dhcp rd.neednet=1 initrd=rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img coreos.inst=yes coreos.inst.install_dev=sda coreos.inst.image_url=http://<HTTP_server>/rhcos-<version>-<architecture>-metal.<architecture>.raw.gz coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign (2) (3)
1 | Specify the location of the kernel file available on your TFTP server. |
2 | If you use multiple NICs, specify a single interface in the ip option.
For example, to use DHCP on a NIC that is named eno1 , set ip=eno1:dhcp . |
3 | Specify locations of the RHCOS files that you uploaded to your
HTTP or TFTP server. The initrd parameter value is the location of the initramfs
file on your TFTP server. The coreos.inst.image_url parameter value is the
location of the compressed metal RAW image on your HTTP server, and the
coreos.inst.ignition_url parameter value is the location of the bootstrap
Ignition config file on your HTTP server. |
This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more |
For iPXE:
kernel http://<HTTP_server>/rhcos-<version>-<architecture>-installer-kernel-<architecture> ip=dhcp rd.neednet=1 initrd=rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img coreos.inst=yes coreos.inst.install_dev=sda coreos.inst.image_url=http://<HTTP_server>/rhcos-<version>-<architecture>-metal.<architecture>.raw.gz coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign (1) (2) initrd http://<HTTP_server>/rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img (3) boot
1 | Specify locations of the RHCOS files that you uploaded to your
HTTP server. The kernel parameter value is the location of the kernel file,
the initrd parameter value references the name of the initramfs file that is
supplied on the following initrd line, the coreos.inst.image_url parameter value
is the location of the compressed metal RAW image, and the coreos.inst.ignition_url
parameter value is the location of the bootstrap Ignition config file. |
2 | If you use multiple NICs, specify a single interface in the ip option.
For example, to use DHCP on a NIC that is named eno1 , set ip=eno1:dhcp . |
3 | Specify the location of the initramfs file that you uploaded to your HTTP
server. |
This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more |
If you use UEFI, perform the following actions:
Provide the EFI binaries and grub.cfg
file that are required for booting the system. You need the shim.efi
binary and the grubx64.efi
binary.
Extract the necessary EFI binaries by mounting the RHCOS ISO on
your host and then mounting the images/efiboot.img
file to your host.
From the efiboot.img
mount point, you then copy the EFI/redhat/shimx64.efi
and
EFI/redhat/grubx64.efi
files to your TFTP server.
# mkdir -p /mnt/{iso,efiboot} # mount -o loop rhcos-installer.x86_64.iso /mnt/iso # mount -o loop,ro /mnt/iso/images/efiboot.img /mnt/efiboot # cp /mnt/efiboot/EFI/redhat/{shimx64.efi,grubx64.efi} . # umount /mnt/{efiboot,iso}
Copy the EFI/redhat/grub.cfg
file that is included in the RHCOS ISO to your TFTP server.
Edit the grub.cfg
file to include the following arguments:
menuentry 'Install Red Hat Enterprise Linux CoreOS' --class fedora --class gnu-linux --class gnu --class os { linux rhcos-<version>-<architecture>-installer-kernel-<architecture> nomodeset rd.neednet=1 coreos.inst=yes coreos.inst.install_dev=sda coreos.inst.image_url=http://<HTTP_server>/rhcos-<version>-<architecture>-metal.<architecture>.raw.gz coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign (1) initrd rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img (2) }
1 | The first argument to the linux line item is the location of the kernel
file that you uploaded to your TFTP server. For the coreos.inst.image_url parameter
value, specify the location of the compressed metal RAW image that you uploaded
to your HTTP server. For the coreos.inst.ignition_url paramter, specify the location of the
bootstrap Ignition config file that you uploaded to your HTTP server. |
2 | Specify the location of the initramfs file that you uploaded to your TFTP
server. |
Continue to create the machines for your cluster.
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 machine before you install the cluster. |
To create the OpenShift Container Platform cluster, you wait for the bootstrap process to complete on the machines that you provisioned by using the Ignition config files that you generated with the installation program.
Create the required infrastructure for the cluster.
You obtained the installation program and generated the Ignition config files for your cluster.
You used the Ignition config files to create RHCOS machines for your cluster.
Monitor the bootstrap process:
$ ./openshift-install --dir=<installation_directory> wait-for bootstrap-complete \ (1) --log-level=info (2) INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com... INFO API v1.17.1 up INFO Waiting up to 30m0s for bootstrapping to complete... INFO It is now safe to remove the bootstrap resources
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 , or
error instead of info . |
The command succeeds when the Kubernetes API server signals that it has been bootstrapped on the control plane machines.
After 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 machine itself. |
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.
Deploy an OpenShift Container Platform cluster.
Install the oc
CLI.
Export the kubeadmin
credentials:
$ 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 oc
commands successfully using the exported configuration:
$ oc whoami system:admin
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.
You added machines to your cluster.
Confirm that the cluster recognizes the machines:
# oc get nodes NAME STATUS ROLES AGE VERSION master-01.example.com Ready master 40d v1.17.1 master-02.example.com Ready master 40d v1.17.1 master-03.example.com Ready master 40d v1.17.1 worker-01.example.com Ready worker 40d v1.17.1 worker-02.example.com Ready worker 40d v1.17.1
The output lists all of the machines that you created.
Review the pending CSRs and ensure that you see the client requests with the Pending
or Approved
status for each machine that you added to the cluster:
$ oc get csr NAME 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 Pending
status, 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 you approve the initial CSRs, the subsequent node client CSRs are automatically approved by the cluster |
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
Now that your client requests are approved, you must review the server requests for each machine that you added to the cluster:
$ oc get csr
NAME 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 Pending
status, 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 Ready
status. Verify this by running the following command:
$ oc get nodes
NAME STATUS ROLES AGE VERSION
master-0 Ready master 73m v1.20.0
master-1 Ready master 73m v1.20.0
master-2 Ready master 74m v1.20.0
worker-0 Ready worker 11m v1.20.0
worker-1 Ready worker 11m v1.20.0
It can take a few minutes after approval of the server CSRs for the machines to transition to the |
For more information on CSRs, see Certificate Signing Requests.
After the control plane initializes, you must immediately configure some Operators so that they all become available.
Your control plane has initialized.
Watch the cluster components come online:
$ watch -n5 oc get clusteroperators NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE authentication 4.4.0 True False False 69s cloud-credential 4.4.0 True False False 12m cluster-autoscaler 4.4.0 True False False 11m console 4.4.0 True False False 46s dns 4.4.0 True False False 11m image-registry 4.4.0 True False False 5m26s ingress 4.4.0 True False False 5m36s kube-apiserver 4.4.0 True False False 8m53s kube-controller-manager 4.4.0 True False False 7m24s kube-scheduler 4.4.0 True False False 12m machine-api 4.4.0 True False False 12m machine-config 4.4.0 True False False 7m36s marketplace 4.4.0 True False False 7m54m monitoring 4.4.0 True False False 7h54s network 4.4.0 True False False 5m9s node-tuning 4.4.0 True False False 11m openshift-apiserver 4.4.0 True False False 11m openshift-controller-manager 4.4.0 True False False 5m943s openshift-samples 4.4.0 True False False 3m55s operator-lifecycle-manager 4.4.0 True False False 11m operator-lifecycle-manager-catalog 4.4.0 True False False 11m service-ca 4.4.0 True False False 11m service-catalog-apiserver 4.4.0 True False False 5m26s service-catalog-controller-manager 4.4.0 True False False 5m25s storage 4.4.0 True False False 5m30s
Configure the Operators that are not available.
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 the Registry Operator is made available.
Instructions for both configuring a persistent volume, which is required for production clusters, and for configuring an empty directory as the storage location, which is available for only non-production clusters, are shown.
To start the image registry, you must change the Image Registry Operator configuration’s managementState
from Removed
to Managed
.
Change managementState
Image Registry Operator configuration from Removed
to Managed
. For example:
$ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"managementState":"Managed"}}'
As a cluster administrator, following installation you must configure your registry to use storage.
Cluster administrator permissions.
A cluster on bare metal.
Persistent storage provisioned for your cluster, such as Red Hat OpenShift Container Storage.
OpenShift Container Platform supports |
Must have 100Gi capacity.
To configure your registry to use storage, change the spec.storage.pvc
in
the configs.imageregistry/cluster
resource.
When using 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
If the storage type is |
Check the registry configuration:
$ oc edit configs.imageregistry.operator.openshift.io
storage:
pvc:
claim:
Leave the claim
field blank to allow the automatic creation of an
image-registry-storage
PVC.
Check the clusteroperator
status:
$ oc get clusteroperator image-registry
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.
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 patch
command fails with the following error:
Error from server (NotFound): configs.imageregistry.operator.openshift.io "cluster" not found
Wait a few minutes and run the command again.
To allow the image registry to use block storage types during upgrades as a cluster administrator, you can use the Recreate
rollout strategy.
Block storage volumes are supported but not recommended for use with the 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. |
To set the image registry storage as a block storage type, patch the registry so that it uses the Recreate
rollout strategy and runs with only one (1
) replica:
$ 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.
Edit the registry configuration so that it references the correct PVC.
After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.
Your control plane has initialized.
You have completed the initial Operator configuration.
Confirm that all the cluster components are online:
$ watch -n5 oc get clusteroperators NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE authentication 4.4.3 True False False 7m56s cloud-credential 4.4.3 True False False 31m cluster-autoscaler 4.4.3 True False False 16m console 4.4.3 True False False 10m csi-snapshot-controller 4.4.3 True False False 16m dns 4.4.3 True False False 22m etcd 4.4.3 False False False 25s image-registry 4.4.3 True False False 16m ingress 4.4.3 True False False 16m insights 4.4.3 True False False 17m kube-apiserver 4.4.3 True False False 19m kube-controller-manager 4.4.3 True False False 20m kube-scheduler 4.4.3 True False False 20m kube-storage-version-migrator 4.4.3 True False False 16m machine-api 4.4.3 True False False 22m machine-config 4.4.3 True False False 22m marketplace 4.4.3 True False False 16m monitoring 4.4.3 True False False 10m network 4.4.3 True False False 23m node-tuning 4.4.3 True False False 23m openshift-apiserver 4.4.3 True False False 17m openshift-controller-manager 4.4.3 True False False 15m openshift-samples 4.4.3 True False False 16m operator-lifecycle-manager 4.4.3 True False False 22m operator-lifecycle-manager-catalog 4.4.3 True False False 22m operator-lifecycle-manager-packageserver 4.4.3 True False False 18m service-ca 4.4.3 True False False 23m service-catalog-apiserver 4.4.3 True False False 23m service-catalog-controller-manager 4.4.3 True False False 23m storage 4.4.3 True False False 17m
When all of the cluster Operators are AVAILABLE
, you can complete the installation.
Monitor for cluster completion:
$ ./openshift-install --dir=<installation_directory> wait-for install-complete (1) INFO Waiting up to 30m0s for the cluster to initialize...
1 | For <installation_directory> , specify the path to the directory that you
stored the installation files in. |
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 |
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-namespaces NAMESPACE 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.
Register your cluster on the Cluster registration page.
If necessary, you can opt out of remote health reporting.