Installing a cluster on GCP with customizations - Installing on GCP | Installing

Prerequisites
Internet access for OpenShift Container Platform
Generating a key pair for cluster node SSH access
Obtaining the installation program
Creating the installation configuration file
Additional resources
- Configuring the cluster-wide proxy during installation
Deploying the cluster
Installing the OpenShift CLI by downloading the binary
Logging in to the cluster by using the CLI
Telemetry access for OpenShift Container Platform
Next steps

In OpenShift Container Platform version 4.10, you can install a customized cluster on infrastructure that the installation program provisions on Google Cloud Platform (GCP). To customize the installation, you modify parameters in the install-config.yaml file before you install the cluster.

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 configured a GCP project to host the cluster.
If you use a firewall, you configured it to allow the sites that your cluster requires access to.
If the cloud identity and access management (IAM) APIs are not accessible in your environment, or if you do not want to store an administrator-level credential secret in the kube-system namespace, you can manually create and maintain IAM credentials.

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.

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 `~/.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.

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
```
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.
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>)
```
Set the GOOGLE_APPLICATION_CREDENTIALS environment variable to the full path to your service account private key file.
```
$ export GOOGLE_APPLICATION_CREDENTIALS="<your_service_account_file>"
```
Verify that the credentials were applied.
```
$ gcloud auth list
```

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

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.
Select your infrastructure provider.

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.

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
```
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.

Creating the installation configuration file

You can customize the OpenShift Container Platform cluster you install on Google Cloud Platform (GCP).

Prerequisites

Obtain the OpenShift Container Platform installation program and the pull secret for your cluster.
Obtain service principal permissions at the subscription level.

Procedure

Create the install-config.yaml file.

Change to the directory that contains the installation program and run the following command:

$ ./openshift-install create install-config --dir <installation_directory> (1)

1	For `<installation_directory>`, specify the directory name to store the files that the installation program creates.

Specify an empty 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.

At the prompts, provide the configuration details for your cloud:
1. Optional: Select an SSH key to use to access your cluster machines.
  
  For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.
2. Select gcp as the platform to target.
3. If you have not configured the service account key for your GCP account on your computer, you must obtain it from GCP and paste the contents of the file or enter the absolute path to the file.
4. Select the project ID to provision the cluster in. The default value is specified by the service account that you configured.
5. Select the region to deploy the cluster to.
6. Select the base domain to deploy the cluster to. The base domain corresponds to the public DNS zone that you created for your cluster.
7. Enter a descriptive name for your cluster.
8. Paste the pull secret from the Red Hat OpenShift Cluster Manager.

Modify the install-config.yaml file. You can find more information about the available parameters in the "Installation configuration parameters" section.
Back up the install-config.yaml file so that you can use it to install multiple clusters.

The install-config.yaml file is consumed during the installation process. If you want to reuse the file, 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 install-config.yaml file.

Required configuration parameters

Required installation configuration parameters are described in the following table:

Table 1. Required parameters
Parameter	Description	Values
`apiVersion`	The API version for the `install-config.yaml` content. The current version is `v1`. The installer may also support older API versions.	String
`baseDomain`	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 `baseDomain` and `metadata.name` parameter values that uses the `<metadata.name>.<baseDomain>` format.	A fully-qualified domain or subdomain name, such as `example.com`.
`metadata`	Kubernetes resource `ObjectMeta`, from which only the `name` parameter is consumed.	Object
`metadata.name`	The name of the cluster. DNS records for the cluster are all subdomains of `{{.metadata.name}}.{{.baseDomain}}`.	String of lowercase letters, hyphens (`-`), and periods (`.`), such as `dev`.
`platform`	The configuration for the specific platform upon which to perform the installation: `alibabacloud`, `aws`, `baremetal`, `azure`, `ibmcloud`, `openstack`, `ovirt`, `vsphere`, or `{}`. For additional information about `platform.<platform>` parameters, consult the table for your specific platform that follows.	Object
`pullSecret`	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.	`{ "auths":{ "cloud.openshift.com":{ "auth":"b3Blb=", "email":"you@example.com" }, "quay.io":{ "auth":"b3Blb=", "email":"you@example.com" } } }`

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.

Parameter Description Values

networking

The configuration for the cluster network.

Object

You cannot modify parameters specified by the networking object after installation.

networking.networkType

The cluster network provider Container Network Interface (CNI) plug-in to install.

Either OpenShiftSDN or OVNKubernetes. The default value is OpenShiftSDN.

networking.clusterNetwork

The IP address blocks for pods.

The default value is 10.128.0.0/14 with a host prefix of /23.

If you specify multiple IP address blocks, the blocks must not overlap.

An array of objects. For example:

networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23

networking.clusterNetwork.cidr

Required if you use networking.clusterNetwork. An IP address block.

An IPv4 network.

An IP address block in Classless Inter-Domain Routing (CIDR) notation. The prefix length for an IPv4 block is between 0 and 32.

networking.clusterNetwork.hostPrefix

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. A hostPrefix value of 23 provides 510 (2^(32 - 23) - 2) pod IP addresses.

A subnet prefix.

The default value is 23.

networking.serviceNetwork

The IP address block for services. The default value is 172.30.0.0/16.

The OpenShift SDN and OVN-Kubernetes network providers support only a single IP address block for the service network.

An array with an IP address block in CIDR format. For example:

networking:
  serviceNetwork:
   - 172.30.0.0/16

networking.machineNetwork

The IP address blocks for machines.

If you specify multiple IP address blocks, the blocks must not overlap.

An array of objects. For example:

networking:
  machineNetwork:
  - cidr: 10.0.0.0/16

networking.machineNetwork.cidr

Required if you use networking.machineNetwork. An IP address block. The default value is 10.0.0.0/16 for all platforms other than libvirt. For libvirt, the default value is 192.168.126.0/24.

An IP network block in CIDR notation.

For example, 10.0.0.0/16.

Set the networking.machineNetwork to match the CIDR that the preferred NIC resides in.

Optional configuration parameters

Optional installation configuration parameters are described in the following table:

Parameter Description Values

additionalTrustBundle

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

cgroupsV2

Enables Linux control groups version 2 (cgroups v2) on specific nodes in your cluster. The OpenShift Container Platform process for enabling cgroups v2 disables all cgroup version 1 controllers and hierarchies. The OpenShift Container Platform cgroups version 2 feature is in Developer Preview and is not supported by Red Hat at this time.

true

compute

The configuration for the machines that comprise the compute nodes.

Array of MachinePool objects.

compute.architecture

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 amd64 (the default).

String

compute.hyperthreading

Whether to enable or disable simultaneous multithreading, or hyperthreading, on compute machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores.

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.

Enabled or Disabled

compute.name

Required if you use compute. The name of the machine pool.

worker

compute.platform

Required if you use compute. Use this parameter to specify the cloud provider to host the worker machines. This parameter value must match the controlPlane.platform parameter value.

alibaba, aws, azure, gcp, ibmcloud, openstack, ovirt, vsphere, or {}

compute.replicas

The number of compute machines, which are also known as worker machines, to provision.

A positive integer greater than or equal to 2. The default value is 3.

controlPlane

The configuration for the machines that comprise the control plane.

Array of MachinePool objects.

controlPlane.architecture

String

controlPlane.hyperthreading

Whether to enable or disable simultaneous multithreading, or hyperthreading, on control plane machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores.

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.

Enabled or Disabled

controlPlane.name

Required if you use controlPlane. The name of the machine pool.

master

controlPlane.platform

Required if you use controlPlane. Use this parameter to specify the cloud provider that hosts the control plane machines. This parameter value must match the compute.platform parameter value.

alibaba, aws, azure, gcp, ibmcloud, openstack, ovirt, vsphere, or {}

controlPlane.replicas

The number of control plane machines to provision.

The only supported value is 3, which is the default value.

credentialsMode

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.

Not all CCO modes are supported for all cloud providers. For more information on CCO modes, see the Cloud Credential Operator entry in the Cluster Operators reference content.

Mint, Passthrough, Manual, or an empty string ("").

fips

Enable or disable FIPS mode. The default is false (disabled). 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.

The use of FIPS Validated / Modules in Process cryptographic libraries is only supported on OpenShift Container Platform deployments on the x86_64 architecture.

If you are using Azure File storage, you cannot enable FIPS mode.

false or true

imageContentSources

Sources and repositories for the release-image content.

Array of objects. Includes a source and, optionally, mirrors, as described in the following rows of this table.

imageContentSources.source

Required if you use imageContentSources. Specify the repository that users refer to, for example, in image pull specifications.

String

imageContentSources.mirrors

Specify one or more repositories that may also contain the same images.

Array of strings

publish

How to publish or expose the user-facing endpoints of your cluster, such as the Kubernetes API, OpenShift routes.

Internal or External. To deploy a private cluster, which cannot be accessed from the internet, set publish to Internal. The default value is External.

sshKey

The SSH key or keys to authenticate access your cluster machines.

For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.

One or more keys. For example:

sshKey:
  <key1>
  <key2>
  <key3>

Additional Google Cloud Platform (GCP) configuration parameters

Additional GCP configuration parameters are described in the following table:

Parameter Description Values

platform.gcp.network

The name of the existing VPC that you want to deploy your cluster to.

String.

platform.gcp.region

The name of the GCP region that hosts your cluster.

Any valid region name, such as us-central1.

platform.gcp.type

The GCP machine type.

platform.gcp.zones

The availability zones where the installation program creates machines for the specified MachinePool.

A list of valid GCP availability zones, such as us-central1-a, in a YAML sequence.

platform.gcp.controlPlaneSubnet

The name of the existing subnet in your VPC that you want to deploy your control plane machines to.

The subnet name.

platform.gcp.computeSubnet

The name of the existing subnet in your VPC that you want to deploy your compute machines to.

The subnet name.

platform.gcp.licenses

A list of license URLs that must be applied to the compute images.

The licenses parameter is a deprecated field and nested virtualization is enabled by default. It is not recommended to use this field.

Any license available with the license API, such as the license to enable nested virtualization. You cannot use this parameter with a mechanism that generates pre-built images. Using a license URL forces the installer to copy the source image before use.

platform.gcp.osDisk.diskSizeGB

The size of the disk in gigabytes (GB).

Any size between 16 GB and 65536 GB.

platform.gcp.osDisk.diskType

The type of disk.

Either the default pd-ssd or the pd-standard disk type. The control plane nodes must be the pd-ssd disk type. The worker nodes can be either type.

controlPlane.platform.gcp.osDisk.encryptionKey.kmsKey.name

The name of the customer managed encryption key to be used for control plane machine disk encryption.

The encryption key name.

controlPlane.platform.gcp.osDisk.encryptionKey.kmsKey.keyRing

For control plane machines, the name of the KMS key ring to which the KMS key belongs.

The KMS key ring name.

controlPlane.platform.gcp.osDisk.encryptionKey.kmsKey.location

For control plane machines, the GCP location in which the key ring exists. For more information on KMS locations, see Google’s documentation on Cloud KMS locations.

The GCP location for the key ring.

controlPlane.platform.gcp.osDisk.encryptionKey.kmsKey.projectID

For control plane machines, the ID of the project in which the KMS key ring exists. This value defaults to the VM project ID if not set.

The GCP project ID.

compute.platform.gcp.osDisk.encryptionKey.kmsKey.name

The name of the customer managed encryption key to be used for compute machine disk encryption.

The encryption key name.

compute.platform.gcp.osDisk.encryptionKey.kmsKey.keyRing

For compute machines, the name of the KMS key ring to which the KMS key belongs.

The KMS key ring name.

compute.platform.gcp.osDisk.encryptionKey.kmsKey.location

For compute machines, the GCP location in which the key ring exists. For more information on KMS locations, see Google’s documentation on Cloud KMS locations.

The GCP location for the key ring.

compute.platform.gcp.osDisk.encryptionKey.kmsKey.projectID

For compute machines, the ID of the project in which the KMS key ring exists. This value defaults to the VM project ID if not set.

The GCP project ID.

Minimum resource requirements for cluster installation

Each cluster machine must meet the following minimum requirements:

Machine	Operating System	vCPU ^[1]	Virtual RAM	Storage	IOPS ^[2]
Bootstrap	RHCOS	4	16 GB	100 GB	300
Control plane	RHCOS	4	16 GB	100 GB	300
Compute	RHCOS, RHEL 8.4, or RHEL 8.5 ^[3]	2	8 GB	100 GB	300

Machine

Operating System

vCPU ^[1]

Virtual RAM

Storage

IOPS ^[2]

Bootstrap

RHCOS

16 GB

100 GB

300

Control plane

RHCOS

16 GB

100 GB

300

Compute

RHCOS, RHEL 8.4, or RHEL 8.5 ^[3]

8 GB

100 GB

300

One vCPU is equivalent to one physical core when simultaneous multithreading (SMT), or hyperthreading, 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.

If an instance type for your platform meets the minimum requirements for cluster machines, it is supported to use in OpenShift Container Platform.

Tested instance types for GCP

The following Google Cloud Platform instance types have been tested with OpenShift Container Platform.

Machine series

C2
E2
M1
N1
N2
N2D
Tau T2D

Sample customized install-config.yaml file for GCP

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.

This sample YAML file is provided for reference only. You must obtain your install-config.yaml file by using the installation program and modify it.

apiVersion: v1
baseDomain: example.com (1)
controlPlane:  (2) (3)
  hyperthreading: Enabled (4)
  name: master
  platform:
    gcp:
      type: n2-standard-4
      zones:
      - us-central1-a
      - us-central1-c
      osDisk:
        diskType: pd-ssd
        diskSizeGB: 1024
        encryptionKey: (5)
          kmsKey:
            name: worker-key
            keyRing: test-machine-keys
            location: global
            projectID: project-id
  replicas: 3
compute:  (2) (3)
- hyperthreading: Enabled (4)
  name: worker
  platform:
    gcp:
      type: n2-standard-4
      zones:
      - us-central1-a
      - us-central1-c
      osDisk:
        diskType: pd-standard
        diskSizeGB: 128
        encryptionKey: (5)
          kmsKey:
            name: worker-key