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In OpenShift Container Platform version 4.10, you can install a cluster on your VMware vSphere instance using installer-provisioned infrastructure with customized network configuration options 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.

By customizing your OpenShift Container Platform network configuration, your cluster can coexist with existing IP address allocations in your environment and integrate with existing VXLAN configurations. To customize the installation, you modify parameters in the install-config.yaml file before you install the cluster. You must set most of the network configuration parameters during installation, and you can modify only kubeProxy configuration parameters in a running cluster.

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.

VMC on AWS Architecture

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.

  • Allocate two IP addresses, outside the DHCP range, and configure them with reverse DNS records.

    • A DNS record for api.<cluster_name>.<base_domain> pointing to the allocated IP address.

    • A DNS record for *.apps.<cluster_name>.<base_domain> pointing to the allocated IP address.

  • Configure the following firewall rules:

    • An ANY:ANY firewall rule between the OpenShift Container Platform compute network and the internet. This is used by nodes and applications to download container images.

    • 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 10.128.0.0/14 and 172.30.0.0/16, 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 WorkloadDatastore

        It is recommended to move your vSphere cluster to the VMC Compute-ResourcePool resource 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-install installation program

      • The OpenShift CLI (oc) tool

You cannot use the VMware NSX Container Plug-in 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

Internet access for OpenShift Container Platform

In OpenShift Container Platform 4.10, you require access to the internet to install your cluster.

You must have internet access to:

  • Access OpenShift Cluster Manager 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 required content and use it to populate a mirror registry with the installation packages. 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.

VMware vSphere infrastructure requirements

You must install the OpenShift Container Platform cluster on a VMware vSphere version 6 or 7 instance that meets the requirements for the components that you use.

Table 1. Version requirements for vSphere virtual environments
Virtual environment product Required version

VM hardware version

13 or later

vSphere ESXi hosts

6.5 or later

vCenter host

6.5 or later

Installing a cluster on VMware vSphere version 6.7U3 or earlier and virtual hardware version 13 is now deprecated. These versions are still fully supported, but version 4.11 of OpenShift Container Platform will require vSphere virtual hardware version 15 or later. Hardware version 15 is now the default for vSphere virtual machines in OpenShift Container Platform. To update the hardware version for your vSphere nodes, see the "Updating hardware on nodes running in vSphere" article.

If your vSphere nodes are below hardware version 15 or your VMware vSphere version is earlier than 6.7U3, upgrading from OpenShift Container Platform 4.10 to OpenShift Container Platform 4.11 is not available.

Table 2. Minimum supported vSphere version for VMware components
Component Minimum supported versions Description

Hypervisor

vSphere 6.5 and later with HW version 13

This version is the minimum version that Red Hat Enterprise Linux CoreOS (RHCOS) supports. See the Red Hat Enterprise Linux 8 supported hypervisors list.

Storage with in-tree drivers

vSphere 6.5 and later

This plug-in creates vSphere storage by using the in-tree storage drivers for vSphere included in OpenShift Container Platform.

If you use a vSphere version 6.5 instance, consider upgrading to 6.7U3 or 7.0 before you install OpenShift Container Platform.

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.

VMware vSphere CSI Driver Operator requirements

The following requirements must be met in order to install the CSI Driver Operator:

  • VMware vSphere version 6.7U3 or later

  • Virtual machines of hardware version 15 or later

  • No third-party CSI driver already installed in the cluster

If a third-party CSI driver is present in the cluster, OpenShift Container Platform does not overwrite it. The presence of a third-party CSI driver prevents OpenShift Container Platform from upgrading to 4.11.

Additional resources

vCenter requirements

Before you install an OpenShift Container Platform cluster on your vCenter that uses infrastructure that the installer provisions, you must prepare your environment.

Required vCenter account privileges

To install an OpenShift Container Platform cluster in a vCenter, the installation program requires access to an account with privileges to read and create the required resources. Using an account that has global administrative privileges is the simplest way to access all of the necessary permissions.

If you cannot use an account with global administrative privileges, you must create roles to grant the privileges necessary for OpenShift Container Platform cluster installation. While most of the privileges are always required, some are required only if you plan for the installation program to provision a folder to contain the OpenShift Container Platform cluster on your vCenter instance, which is the default behavior. You must create or amend vSphere roles for the specified objects to grant the required privileges.

An additional role is required if the installation program is to create a vSphere virtual machine folder.

Roles and privileges required for installation
vSphere object for role When required Required privileges

vSphere vCenter

Always

Cns.Searchable
InventoryService.Tagging.AttachTag
InventoryService.Tagging.CreateCategory
InventoryService.Tagging.CreateTag
InventoryService.Tagging.DeleteCategory
InventoryService.Tagging.DeleteTag
InventoryService.Tagging.EditCategory
InventoryService.Tagging.EditTag
Sessions.ValidateSession
StorageProfile.Update
StorageProfile.View

vSphere vCenter Cluster

Always

Host.Config.Storage
Resource.AssignVMToPool
VApp.AssignResourcePool
VApp.Import
VirtualMachine.Config.AddNewDisk

vSphere Datastore

Always

Datastore.AllocateSpace
Datastore.Browse
Datastore.FileManagement
InventoryService.Tagging.ObjectAttachable

vSphere Port Group

Always

Network.Assign

Virtual Machine Folder

Always

Resource.AssignVMToPool
VApp.Import
VirtualMachine.Config.AddExistingDisk
VirtualMachine.Config.AddNewDisk
VirtualMachine.Config.AddRemoveDevice
VirtualMachine.Config.AdvancedConfig
VirtualMachine.Config.Annotation
VirtualMachine.Config.CPUCount
VirtualMachine.Config.DiskExtend
VirtualMachine.Config.DiskLease
VirtualMachine.Config.EditDevice
VirtualMachine.Config.Memory
VirtualMachine.Config.RemoveDisk
VirtualMachine.Config.Rename
VirtualMachine.Config.ResetGuestInfo
VirtualMachine.Config.Resource
VirtualMachine.Config.Settings
VirtualMachine.Config.UpgradeVirtualHardware
VirtualMachine.Interact.GuestControl
VirtualMachine.Interact.PowerOff
VirtualMachine.Interact.PowerOn
VirtualMachine.Interact.Reset
VirtualMachine.Inventory.Create
VirtualMachine.Inventory.CreateFromExisting
VirtualMachine.Inventory.Delete
VirtualMachine.Provisioning.Clone
VirtualMachine.Provisioning.MarkAsTemplate
VirtualMachine.Provisioning.DeployTemplate

vSphere vCenter Datacenter

If the installation program creates the virtual machine folder

Resource.AssignVMToPool
VApp.Import
VirtualMachine.Config.AddExistingDisk
VirtualMachine.Config.AddNewDisk
VirtualMachine.Config.AddRemoveDevice
VirtualMachine.Config.AdvancedConfig
VirtualMachine.Config.Annotation
VirtualMachine.Config.CPUCount
VirtualMachine.Config.DiskExtend
VirtualMachine.Config.DiskLease
VirtualMachine.Config.EditDevice
VirtualMachine.Config.Memory
VirtualMachine.Config.RemoveDisk
VirtualMachine.Config.Rename
VirtualMachine.Config.ResetGuestInfo
VirtualMachine.Config.Resource
VirtualMachine.Config.Settings
VirtualMachine.Config.UpgradeVirtualHardware
VirtualMachine.Interact.GuestControl
VirtualMachine.Interact.PowerOff
VirtualMachine.Interact.PowerOn
VirtualMachine.Interact.Reset
VirtualMachine.Inventory.Create
VirtualMachine.Inventory.CreateFromExisting
VirtualMachine.Inventory.Delete
VirtualMachine.Provisioning.Clone
VirtualMachine.Provisioning.DeployTemplate
VirtualMachine.Provisioning.MarkAsTemplate
Folder.Create
Folder.Delete

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 Folder type Propagate to children Permissions required

vSphere vCenter

Always

False

Listed required privileges

vSphere vCenter Datacenter

Existing folder

False

ReadOnly permission

Installation program creates the folder

True

Listed required privileges

vSphere vCenter Cluster

Always

True

Listed required privileges

vSphere vCenter Datastore

Always

False

Listed required privileges

vSphere Switch

Always

False

ReadOnly permission

vSphere Port Group

Always

False

Listed required privileges

vSphere vCenter Virtual Machine Folder

Existing folder

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

OpenShift Container Platform generally supports compute-only vMotion. Using Storage vMotion can cause issues and is not supported.

If you are using 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. These references prevent affected pods from starting up and can result in data loss.

Similarly, 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 installer-provisioned infrastructure, the installation program must be able to create several resources in your vCenter instance.

A standard OpenShift Container Platform installation creates the following vCenter resources:

  • 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 must use DHCP for the network and ensure that the DHCP server is configured to provide persistent IP addresses to the cluster machines. All nodes must be in the same VLAN. You cannot scale the cluster using a second VLAN as a Day 2 operation. Additionally, you must create the following networking resources before you install the OpenShift Container Platform cluster:

It is recommended that each OpenShift Container Platform node in the cluster must have access to a Network Time Protocol (NTP) server that is discoverable via DHCP. Installation is possible without an NTP server. However, asynchronous server clocks will cause errors, which NTP server prevents.

Required IP Addresses

An installer-provisioned vSphere installation requires two static IP addresses:

  • The API address is used to access the cluster API.

  • The Ingress address is used for cluster ingress traffic.

You must provide these IP addresses to the installation program when you install the OpenShift Container Platform cluster.

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>..

Table 3. Required DNS records
Component Record Description

API VIP

api.<cluster_name>.<base_domain>.

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

*.apps.<cluster_name>.<base_domain>.

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.

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
  1. 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 ~/.ssh directory.

    If you plan to install an OpenShift Container Platform cluster that uses FIPS Validated / Modules in Process cryptographic libraries on the x86_64 architecture, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.

  2. View the public SSH key:

    $ cat <path>/<file_name>.pub

    For example, run the following to view the ~/.ssh/id_ed25519.pub public key:

    $ cat ~/.ssh/id_ed25519.pub
  3. 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 gather command.

    On some distributions, default SSH private key identities such as ~/.ssh/id_rsa and ~/.ssh/id_dsa are managed automatically.

    1. If the ssh-agent process is not already running for your local user, start it as a background task:

      $ eval "$(ssh-agent -s)"
      Example output
      Agent pid 31874

      If your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.

  4. 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_ed25519
    Example output
    Identity 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.

Obtaining the installation program

Before you install OpenShift Container Platform, download the installation file on a local computer.

Prerequisites
  • You have a computer that runs Linux or macOS, with 500 MB of local disk space

Procedure
  1. Access the Infrastructure Provider page on the OpenShift Cluster Manager site. If you have a Red Hat account, log in with your credentials. If you do not, create an account.

  2. Select your infrastructure provider.

  3. Navigate to the page for your installation type, download the installation program that corresponds with your host operating system and architecture, and place the file in the directory where you will store the installation configuration files.

    The installation program creates several files on the computer that you use to install your cluster. You must keep the installation program and the files that the installation program creates after you finish installing the cluster. Both files are required to delete the cluster.

    Deleting the files created by the installation program does not remove your cluster, even if the cluster failed during installation. To remove your cluster, complete the OpenShift Container Platform uninstallation procedures for your specific cloud provider.

  4. Extract the installation program. For example, on a computer that uses a Linux operating system, run the following command:

    $ tar -xvf openshift-install-linux.tar.gz
  5. Download your installation pull secret from the Red Hat OpenShift Cluster Manager. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OpenShift Container Platform components.

Adding vCenter root CA certificates to your system trust

Because the installation program requires access to your vCenter’s API, you must add your vCenter’s trusted root CA certificates to your system trust before you install an OpenShift Container Platform cluster.

Procedure
  1. From the vCenter home page, download the vCenter’s root CA certificates. Click Download trusted root CA certificates in the vSphere Web Services SDK section. The <vCenter>/certs/download.zip file downloads.

  2. Extract the compressed file that contains the vCenter root CA certificates. The contents of the compressed file resemble the following file structure:

    certs
    ├── lin
    │   ├── 108f4d17.0
    │   ├── 108f4d17.r1
    │   ├── 7e757f6a.0
    │   ├── 8e4f8471.0
    │   └── 8e4f8471.r0
    ├── mac
    │   ├── 108f4d17.0
    │   ├── 108f4d17.r1
    │   ├── 7e757f6a.0
    │   ├── 8e4f8471.0
    │   └── 8e4f8471.r