volrep-shim-operator

README

VolumeReplication Operator Shim

VolumeReplication Operator is a shim for a sample VolumeReplication kubernetes CRD that,

• Uses the VolumeReplication CRD and manages its reconciliation
• The PVC that is managed is as per the dataSource in the VolumeReplication CR and dataSource only handles PVCs at present
• The operator reconciles the VolumeReplication CR based on PVC health (i.e it should be bound to a PV), and reflects the following in status
  • observedState reflects the state observed at the generation in observedGeneration
  • observedGeneration reflects the generation of the most recently observed volume replication
  • conditions
    • Type: "Reconciled" denotes resource was reconciled
      • Status: "Complete" denotes reconciliation was completed
      • Status: "Error" denotes reconciliation had errors

NOTE: Currently the shim operator supports (or, is tested with) kubernetes v1.19 and above

Build

The code is generated using the operator-sdk and comes with standard SDK targets in the Makefile.

The most common way to build an image would be,

$ make docker-build IMG=volrep-shim-operator:latest

To push the image to a docker repository use,

$ make docker-push docker-push IMG=volrep-shim-operator:latest

Deploy

Deploy to a kubernetes instance using,

$ make deploy IMG=volrep-shim-operator:latest

The artifacts are deployed in the volreplication-shim-system namespace and are,

$ kubectl get all -n volreplication-shim-system
NAME                                                          READY   STATUS    RESTARTS   AGE
pod/volreplication-shim-controller-manager-744cb9dc78-47ptb   2/2     Running   0          3m56s

NAME                                                             TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
service/volreplication-shim-controller-manager-metrics-service   ClusterIP   10.104.17.255   <none>        8443/TCP   3m56s

NAME                                                     READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/volreplication-shim-controller-manager   1/1     1            1           3m56s

NAME                                                                DESIRED   CURRENT   READY   AGE
replicaset.apps/volreplication-shim-controller-manager-744cb9dc78   1         1         1       3m56s

Test

The sample VolumeReplication CR can be applied to the cluster running the operator as follows,

$ kubectl apply -f config/samples/replication_v1alpha1_volumereplication.yaml

NOTE: Sample above requires that a PVC named "sample-pvc" exists in the same namespace as the VolumeReplication resource

The reconcile logs can be viewed in parallel for the reconcile of the above created CR as follows,

$ kubectl logs -fn volreplication-shim-system deployment.apps/volreplication-shim-controller-manager -c manager

The status of reconciliation can be observed using,

$ kubectl get volumereplication volumereplication-sample -o jsonpath='{.status}'

Testing with minikube is the simplest, and a sample minikube PVC is present here.

If using podman to build and minikube with docker, then a helper script to copy the built image into minikube is present here