feat(kubernetes): permit multiple ReplicaSets to be deployed with a s…

…ingle rollout strategy config (#4126)

clouddriver-kubernetes-v2/src/main/java/com/netflix/spinnaker/clouddriver/kubernetes/v2/op/manifest/KubernetesDeployManifestOperation.java

@@ -98,8 +98,6 @@ public OperationResult operate(List _unused) {
 
     Set<Artifact> boundArtifacts = new HashSet<>();
 
-    validateManifestsForRolloutStrategies(inputManifests);
-
     for (KubernetesManifest manifest : inputManifests) {
       if (credentials.getKindRegistry().getKindProperties(manifest.getKind()).isNamespaced()) {
         if (!StringUtils.isEmpty(description.getNamespaceOverride())) {
@@ -251,15 +249,6 @@ private void applyTraffic(KubernetesManifestTraffic traffic, KubernetesManifest
     traffic.getLoadBalancers().forEach(l -> attachLoadBalancer(l, target));
   }
 
-  private void validateManifestsForRolloutStrategies(List<KubernetesManifest> manifests) {
-    long numReplicaSets =
-        manifests.stream().filter(m -> m.getKind().equals(KubernetesKind.REPLICA_SET)).count();
-    if (description.getStrategy() != null && numReplicaSets != 1) {
-      throw new RuntimeException(
-          "Spinnaker can manage traffic for one ReplicaSet only. Please deploy one ReplicaSet manifest or disable rollout strategies.");
-    }
-  }
-
   private void attachLoadBalancer(String loadBalancerName, KubernetesManifest target) {
     Pair<KubernetesKind, String> name;
     try {