perf(kubernetes): Store Kind on the KubernetesManifest object (#3853)

* perf(kubernetes): Use null instead of optional

We create a lot of ScopedKind objects to look up kinds, so the
cost of creating an Optional each time is non-negligible.

In general using Optional can be more readable than null but in this
case we'd rather the performance of null (and it's just as easy to read
here).

* perf(kubernetes): Store Kind on the KubernetesManifest object

In processing manifests, we call getKind() multiple times per
manifest. It's not a cheap accessor as it needs to look up kinds
in the kind registry.

While recent changes have made looking up kinds a lot more efficient,
it still doesn't make sense to re-do this work multiple times per
manifest.

Compute the kind on-demand and store it on the object; clear the
cached value if we change either the kind or api group on the manifest.

clouddriver-kubernetes/src/main/groovy/com/netflix/spinnaker/clouddriver/kubernetes/v2/description/manifest/KubernetesKind.java

@@ -259,7 +259,7 @@ public static class ScopedKind {
     public ScopedKind(@Nonnull String name, @Nullable KubernetesApiGroup apiGroup) {
       this.name = name;
       this.lcName = name.toLowerCase();
-      this.apiGroup = Optional.ofNullable(apiGroup).orElse(KubernetesApiGroup.NONE);
+      this.apiGroup = apiGroup == null ? KubernetesApiGroup.NONE : apiGroup;
       if (this.apiGroup.isNativeGroup()) {
         this.customApiGroup = null;
       } else {

clouddriver-kubernetes/src/main/groovy/com/netflix/spinnaker/clouddriver/kubernetes/v2/description/manifest/KubernetesManifest.java

@@ -26,6 +26,7 @@
 import java.util.Map;
 import java.util.Optional;
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 import lombok.Data;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.tuple.ImmutablePair;
@@ -34,6 +35,8 @@
 public class KubernetesManifest extends HashMap<String, Object> {
   private static ObjectMapper mapper = new ObjectMapper();
 
+  @Nullable private KubernetesKind computedKind;
+
   @Override
   public KubernetesManifest clone() {
     return (KubernetesManifest) super.clone();
@@ -51,6 +54,14 @@ private static <T> T getRequiredField(KubernetesManifest manifest, String field)
   @JsonIgnore
   @Nonnull
   public KubernetesKind getKind() {
+    if (computedKind == null) {
+      computedKind = computeKind();
+    }
+    return computedKind;
+  }
+
+  @Nonnull
+  private KubernetesKind computeKind() {
     // using ApiVersion here allows a translation from a kind of NetworkPolicy in the manifest to
     // something
     // like  NetworkPolicy.crd.projectcalico.org for custom resources
@@ -72,6 +83,7 @@ public String getKindName() {
   @JsonIgnore
   public void setKind(KubernetesKind kind) {
     put("kind", kind.toString());
+    computedKind = null;
   }
 
   @JsonIgnore
@@ -82,6 +94,7 @@ public KubernetesApiVersion getApiVersion() {
   @JsonIgnore
   public void setApiVersion(KubernetesApiVersion apiVersion) {
     put("apiVersion", apiVersion.toString());
+    computedKind = null;
   }
 
   @JsonIgnore

clouddriver-kubernetes/src/test/groovy/com/netflix/spinnaker/clouddriver/kubernetes/v2/description/KubernetesManifestSpec.groovy

@@ -129,4 +129,34 @@ class KubernetesManifestSpec extends Specification {
     then:
     manifest.isNewerThanObservedGeneration()
   }
+
+  void "correctly handles a change to the manifest's kind"() {
+    when:
+    def testPayload =  gsonObj.fromJson(basicManifestSource(), Object)
+    KubernetesManifest manifest = objectToManifest(testPayload)
+
+    then:
+    manifest.getKind() == KIND
+
+    when:
+    manifest.setKind(KubernetesKind.DEPLOYMENT)
+
+    then:
+    manifest.getKind() == KubernetesKind.DEPLOYMENT
+  }
+
+  void "correctly handles a change to the manifest's API group"() {
+    when:
+    def testPayload =  gsonObj.fromJson(basicManifestSource(), Object)
+    KubernetesManifest manifest = objectToManifest(testPayload)
+
+    then:
+    manifest.getApiVersion() == KubernetesApiVersion.EXTENSIONS_V1BETA1
+
+    when:
+    manifest.setApiVersion(KubernetesApiVersion.NETWORKING_K8S_IO_V1)
+
+    then:
+    manifest.getApiVersion() == KubernetesApiVersion.NETWORKING_K8S_IO_V1
+  }
 }