default to two replicas

Author: gman0

config/crd/bases/operator.kcp.io_cacheservers.yaml

@@ -1471,8 +1471,9 @@ spec:
               replicas:
                 description: |-
                   Optional: Replicas configures the replica count for the cache-server Deployment.
-                  Defaults to a single replica. If configured with more than one replica,
-                  etcd must be configured too.
+                  With an embedded etcd, the replica count defafults to one, and users are not allowed
+                  to set the replica count to more than one.
+                  With an external etcd, the replica count defaults to two.
                 format: int32
                 type: integer
               serviceTemplate:

internal/resources/cacheserver/deployment.go

@@ -85,7 +85,8 @@ func DeploymentReconciler(server *operatorv1alpha1.CacheServer) reconciling.Name
 					dep.Spec.Replicas = ptr.To(int32(1))
 				}
 			} else {
-				dep.Spec.Replicas = server.Spec.Replicas
+				// We are running with an external etcd. Default to 2 replicas.
+				dep.Spec.Replicas = ptr.To(ptr.Deref(server.Spec.Replicas, 2))
 			}
 
 			dep.Spec.Template.SetLabels(labels)

sdk/apis/operator/v1alpha1/cacheserver_types.go

@@ -31,8 +31,9 @@ type CacheServerSpec struct {
 	Image *ImageSpec `json:"image,omitempty"`
 
 	// Optional: Replicas configures the replica count for the cache-server Deployment.
-	// Defaults to a single replica. If configured with more than one replica,
-	// etcd must be configured too.
+	// With an embedded etcd, the replica count defafults to one, and users are not allowed
+	// to set the replica count to more than one.
+	// With an external etcd, the replica count defaults to two.
 	Replicas *int32 `json:"replicas,omitempty"`
 
 	// Optional: Logging configures the logging settings for the cache server.