Creating an OpenShift Cluster

Follow the instructions below to define the OpenShift cluster resource requirements and then create the cluster based on your specifications.

An example configuration file is provided in [install-config.yaml](https://docs.sw.siemens.com/documentation/external/PL20260212925461721/en-US/graph_studio/attachments/install-config.yaml.txt).

This setup will bring up three system/master nodes and three worker nodes. The nodes are GCP VM instances.

Make sure to make a backup of [install-config.yaml](https://docs.sw.siemens.com/documentation/external/PL20260212925461721/en-US/graph_studio/attachments/install-config.yaml.txt) so that it can be referred to for multiple installations.

Details of each parameter are as follows.

1. 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>. format.

2. 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.

3. controlPlane: The configuration of the machines that comprise the control plane.

4. platform: Use this parameter to specify the cloud provider that hosts the control plane machines. This parameter value must match the compute.platform parameter value. In this case, it is GCP.

5. gcp.instanceType: GCP VM instance type

6. gcp.Zones: Geographical zones in which the VM instances hosting OpenShift cluster will be deployed

7. osDisk: Consists of diskType(pd-ssd, pd-standard) to be used and diskSizeGB for the base disk size for VM instance of control plane.

8. tags: Network tags to be applied for VM instances, this is mainly applicable when firewall rules come in picture to allow communication between instances.

9. replicas: Number of VM instances to be created for control plane.

10. compute: List of the configuration for the machines that comprise the compute nodes. The spec is almost similar to the control plane. Please refer to point #3 above.

11. metadata.name: Name for the OpenShift cluster to be created

12. networking:

13. 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.

14. networkType: The Red Hat OpenShift Networking plugin to install. OVNKubernetes is a CNI plugin for Linux networks and hybrid networks that contain both Linux and Windows servers. The default value is OVNKubernetes.

15. machineNetwork: The IP address blocks for machines. If you specify multiple IP address blocks, the blocks must not overlap.

16. serviceNetwork: The IP address block for services. The default value is 172.30.0.0/16. The OVN-Kubernetes network plugins supports only a single IP address block for the service network. If you use the OVN-Kubernetes network plugin, you can specify an IP address block for both of the IPv4 and IPv6 address families.

17. platform: Details about GCP project and networking collectively. E.g. region, project id, name of existing control plane subnetwork and network

18. pullSecret: Need to fetch this from redhat account. Refer to ‘Get a pull secret from Red Hat OpenShift Cluster Manager to authenticate downloading container images for OpenShift Container Platform components from services such as Quay.io.’

19. fips: Set this to true if you operate OpenShift cluster in FIPS mode. Also, refer to Chapter 2. Switching RHEL to FIPS Mode for any additional configuration details.

20. sshKey: The SSH key to authenticate access to your cluster machines.

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

Commands that will help to create the cluster with the above configuration, i.e., three master and three worker nodes, are as follows.

mkdir -p openshift-fips-cluster/ cd openshift-fips-cluster

save above yaml file as install-config.yaml in this directory

mkdir -p install_dir/ ./openshift-install-fips create install-config --dir install_dir/ --log-level info

Create manifests

/openshift-install-fips create manifests --dir install_dir/ --log-level info /openshift-install-fips create cluster --dir install_dir/ --log-level info cp install_dir/auth/kubeconfig $HOME/.kube/config

Two subnetworks must be created in the existing VPC network: one for the control plane/master nodes and the other for data plane or worker nodes.