Upgrade a Couchbase Deployment

How-to upgrade Couchbase Server to a newer version.

Given the existing configuration:

apiVersion: couchbase.com/v2
kind: CouchbaseCluster
spec:
  image: couchbase/server:6.0.0 (1)
1 spec.image can be modified to any valid Couchbase Server image, in this example we want to upgrade the version only.
apiVersion: couchbase.com/v2
kind: CouchbaseCluster
spec:
  image: couchbase/server:6.5.0 (1)
1 The modification will trigger the Operator to detect that existing pod specifications do not match the existing pod specifications. This will perform a rolling upgrade of Couchbase Server.