Customize Vanilla Kubernetes cluster

Ops teams might need to adjust the configuration of a Vanilla Kubernetes cluster after the installation process is complete.

These examples cover advanced usage of Kubernetes clusters. They assume a strong understanding of Kubernetes.

1. Persistent storage

If you need to customize your persistent storage, you’ll need to add information to the existing storage.yml file created during the storage classes creation of the installation process.

1.1. Example: Ceph

The Saagie SRE uses Ceph with the provisioner ceph.com/rbd. Here is an example of their configuration. Yours will depend on your storage technology and your provisioner.

To use Ceph, add the following configuration to your existing storage.yml file:

---
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: common-storageclass
provisioner: ceph.com/rbd
allowVolumeExpansion: true
parameters:
  monitors: <array of ips> (1)
  adminId: admin
  adminSecretName: ceph-secret-admin
  adminSecretNamespace: kube-system
  pool: common
  userId: common
  userSecretName: ceph-secret-common
  fsType: ext4
  imageFormat: "2"
  imageFeatures: "layering"
---
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: <customer name>-storageclass (2)
provisioner: ceph.com/rbd
allowVolumeExpansion: true
parameters:
  monitors: <array of ips>
  adminId: admin
  adminSecretName: ceph-secret-admin
  adminSecretNamespace: kube-system
  pool: <pool id> (3)
  userId: <user id> (4)
  userSecretName: ceph-secret-<customer name>
  fsType: ext4
  imageFormat: "2"
  imageFeatures: "layering"
---
apiVersion: v1
data:
  key: <key>
kind: Secret
metadata:
  name: ceph-secret-<customer name>
  namespace: saagie-common
type: ceph.com/rbd
---
apiVersion: v1
data:
  key: <key> (5)
kind: Secret
metadata:
  name: ceph-secret-common
  namespace: saagie-common
type: ceph.com/rbd

1	`<array of ips>` for monitors is provided by the SRE team. Example: `192.168.50.100:6789,192.168.50.101:6789,192.168.50.102:6789,192.168.50.110:6789,192.168.50.111:6789,192.168.50.112:6789`
2	`<customer name>` is the platform URL prefix given during installation.
3	`<pool id>` is provided by the SRE team.
4	`<user id>` is provided by the SRE team.
5	`<key>` is provided by the SRE team.

1.2. Example: NFS

To use NFS, add the following configuration to your existing storage.yml file:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: managed-nfs-storage
provisioner: nfsprovisioner/ifs
parameters:
  archiveOnDelete: "false"