Cannot change the type of the Service from ClusterIP to ExternalName

[stefanrosca]

The current implementation ignores changes to the ClusterIP field (related to: #1925), it copies the old value from the server entity and does not include it in the PATCH call.

When editing the 'type' field from ClusterIP to ExternalName the API Servers enforces the ClusterIP field to be empty making the edit impossible using the kubernetes-client.

Validation message: Message: Service "elasticsearch-logging" is invalid: spec.clusterIP: Forbidden: must be empty for ExternalName services. Received status: Status(apiVersion=v1, code=422, details=StatusDetails(causes=[StatusCause(field=spec.clusterIP, message=Forbidden: must be empty for ExternalName services, reason=FieldValueForbidden, additionalProperties={})], group=null, kind=Service, name=elasticsearch-logging, retryAfterSeconds=null, uid=null, additionalProperties={}), kind=Status, message=Service "elasticsearch-logging" is invalid: spec.clusterIP: Forbidden: must be empty for ExternalName services, metadata=ListMeta(_continue=null, remainingItemCount=null, resourceVersion=null, selfLink=null, additionalProperties={}), reason=Invalid, status=Failure, additionalProperties={}).

[rohanKanojia]

We have refactored createOrReplace in #2292 to follow POST -> PATCH as a fallback approach. I think we should remove this code which seems to be adding this:

kubernetes-client/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/dsl/internal/core/v1/ServiceOperationsImpl.java

Lines 61 to 70 in e8c47dc

	try {
	Service old = fromServer().get();
	return super.replace(new ServiceBuilder(item)
	.editSpec()
	.withClusterIP(old.getSpec().getClusterIP())
	.endSpec()
	.build());
	} catch (Exception e) {
	throw KubernetesClientException.launderThrowable(forOperationType("replace"), e);
	}