feat: use SSA matcher flag for child resources

docs/reference.md

@@ -40,6 +40,10 @@ It has several attributes:
    (Same as `reconcilePrecondition` in Java Operator SDK)
 - **`readyPostCondition`** - condition to check if the resource is considered to be ready. If a resource is ready all the resources, which depend on it
    can proceed in reconciliation.
+- **`matcher`** - Match resources with Java Operator SDK Server Side Apply based matcher (default `SSA`). Matching resources
+  is makes the reconciliation much more efficient, since controller updates the resource only if truly changed. However,
+  it is not possible to match resources because of some characteristics of Kubernetes API (default values, value conversions, etc)
+  so you can always opt out the matching (use value `NONE`), and update the resource on every reconciliation.
 
 #### Built-in conditions
 

src/main/java/io/javaoperatorsdk/operator/glue/customresource/glue/DependentResourceSpec.java

@@ -21,6 +21,8 @@ public class DependentResourceSpec {
 
   private String resourceTemplate;
 
+  private Matcher matcher = Matcher.SSA;
+
   private List<String> dependsOn = new ArrayList<>();
 
   @PreserveUnknownFields
@@ -92,6 +94,14 @@ public void setClusterScoped(boolean clusterScoped) {
     this.clusterScoped = clusterScoped;
   }
 
+  public Matcher getMatcher() {
+    return matcher;
+  }
+
+  public void setMatcher(Matcher matcher) {
+    this.matcher = matcher;
+  }
+
   @Override
   public boolean equals(Object o) {
     if (this == o)
@@ -101,15 +111,15 @@ public boolean equals(Object o) {
     DependentResourceSpec that = (DependentResourceSpec) o;
     return clusterScoped == that.clusterScoped && Objects.equals(name, that.name)
         && Objects.equals(resource, that.resource)
-        && Objects.equals(resourceTemplate, that.resourceTemplate)
+        && Objects.equals(resourceTemplate, that.resourceTemplate) && matcher == that.matcher
         && Objects.equals(dependsOn, that.dependsOn)
         && Objects.equals(readyPostCondition, that.readyPostCondition)
         && Objects.equals(condition, that.condition);
   }
 
   @Override
   public int hashCode() {
-    return Objects.hash(name, clusterScoped, resource, resourceTemplate, dependsOn,
+    return Objects.hash(name, clusterScoped, resource, resourceTemplate, matcher, dependsOn,
         readyPostCondition, condition);
   }
 }

src/main/java/io/javaoperatorsdk/operator/glue/customresource/glue/Matcher.java

@@ -0,0 +1,5 @@
+package io.javaoperatorsdk.operator.glue.customresource.glue;
+
+public enum Matcher {
+  NONE, SSA
+}

src/main/java/io/javaoperatorsdk/operator/glue/dependent/GCGenericDependentResource.java

@@ -3,19 +3,20 @@
 import io.fabric8.kubernetes.api.model.GenericKubernetesResource;
 import io.javaoperatorsdk.operator.api.reconciler.dependent.GarbageCollected;
 import io.javaoperatorsdk.operator.glue.customresource.glue.Glue;
+import io.javaoperatorsdk.operator.glue.customresource.glue.Matcher;
 import io.javaoperatorsdk.operator.glue.templating.GenericTemplateHandler;
 
 public class GCGenericDependentResource extends GenericDependentResource
     implements GarbageCollected<Glue> {
 
   public GCGenericDependentResource(GenericTemplateHandler genericTemplateHandler,
       GenericKubernetesResource desired, String name,
-      boolean clusterScoped) {
-    super(genericTemplateHandler, desired, name, clusterScoped);
+      boolean clusterScoped, Matcher matcher) {
+    super(genericTemplateHandler, desired, name, clusterScoped, matcher);
   }
 
   public GCGenericDependentResource(GenericTemplateHandler genericTemplateHandler,
-      String desiredTemplate, String name, boolean clusterScoped) {
-    super(genericTemplateHandler, desiredTemplate, name, clusterScoped);
+      String desiredTemplate, String name, boolean clusterScoped, Matcher matcher) {
+    super(genericTemplateHandler, desiredTemplate, name, clusterScoped, matcher);
   }
 }

src/main/java/io/javaoperatorsdk/operator/glue/dependent/GenericDependentResource.java

@@ -6,6 +6,7 @@
 import io.javaoperatorsdk.operator.api.reconciler.dependent.Deleter;
 import io.javaoperatorsdk.operator.glue.Utils;
 import io.javaoperatorsdk.operator.glue.customresource.glue.Glue;
+import io.javaoperatorsdk.operator.glue.customresource.glue.Matcher;
 import io.javaoperatorsdk.operator.glue.reconciler.glue.GlueReconciler;
 import io.javaoperatorsdk.operator.glue.templating.GenericTemplateHandler;
 import io.javaoperatorsdk.operator.processing.GroupVersionKind;
@@ -23,28 +24,31 @@ public class GenericDependentResource
   private final String desiredTemplate;
   private final String name;
   private final boolean clusterScoped;
+  private final Matcher matcher;
 
   // optimize share between instances
   private final GenericTemplateHandler genericTemplateHandler;
 
   public GenericDependentResource(GenericTemplateHandler genericTemplateHandler,
       GenericKubernetesResource desired, String name,
-      boolean clusterScoped) {
+      boolean clusterScoped, Matcher matcher) {
     super(new GroupVersionKind(desired.getApiVersion(), desired.getKind()));
     this.desired = desired;
+    this.matcher = matcher;
     this.desiredTemplate = null;
     this.name = name;
     this.clusterScoped = clusterScoped;
     this.genericTemplateHandler = genericTemplateHandler;
   }
 
   public GenericDependentResource(GenericTemplateHandler genericTemplateHandler,
-      String desiredTemplate, String name, boolean clusterScoped) {
+      String desiredTemplate, String name, boolean clusterScoped, Matcher matcher) {
     super(new GroupVersionKind(Utils.getApiVersionFromTemplate(desiredTemplate),
         Utils.getKindFromTemplate(desiredTemplate)));
     this.genericTemplateHandler = genericTemplateHandler;
     this.name = name;
     this.desiredTemplate = desiredTemplate;
+    this.matcher = matcher;
     this.desired = null;
     this.clusterScoped = clusterScoped;
   }
@@ -75,6 +79,10 @@ public Result<GenericKubernetesResource> match(GenericKubernetesResource actualR
         && actualResource.getApiVersion().equals("apps/v1")) {
       return super.match(actualResource, primary, context);
     }
-    return Result.nonComputed(false);
+    if (Matcher.SSA.equals(matcher)) {
+      return super.match(actualResource, primary, context);
+    } else {
+      return Result.nonComputed(false);
+    }
   }
 }

src/main/java/io/javaoperatorsdk/operator/glue/reconciler/glue/GlueReconciler.java

@@ -211,16 +211,17 @@ private GenericDependentResource createDependentResource(DependentResourceSpec s
       return spec.getResourceTemplate() != null
           ? new GCGenericDependentResource(genericTemplateHandler, spec.getResourceTemplate(),
               spec.getName(),
-              spec.isClusterScoped())
+              spec.isClusterScoped(), spec.getMatcher())
           : new GCGenericDependentResource(genericTemplateHandler, spec.getResource(),
               spec.getName(),
-              spec.isClusterScoped());
+              spec.isClusterScoped(), spec.getMatcher());
     } else {
       return spec.getResourceTemplate() != null
           ? new GenericDependentResource(genericTemplateHandler,
-              spec.getResourceTemplate(), spec.getName(), spec.isClusterScoped())
+              spec.getResourceTemplate(), spec.getName(), spec.isClusterScoped(),
+              spec.getMatcher())
           : new GenericDependentResource(genericTemplateHandler,
-              spec.getResource(), spec.getName(), spec.isClusterScoped());
+              spec.getResource(), spec.getName(), spec.isClusterScoped(), spec.getMatcher());
     }
   }
 

src/test/java/io/javaoperatorsdk/operator/glue/GlueTest.java

@@ -22,6 +22,7 @@
 import io.javaoperatorsdk.operator.glue.reconciler.ValidationAndErrorHandler;
 import io.quarkus.test.junit.QuarkusTest;
 
+import static io.javaoperatorsdk.operator.glue.TestUtils.INITIAL_RECONCILE_WAIT_TIMEOUT;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.awaitility.Awaitility.await;
 
@@ -354,6 +355,19 @@ void pathRelatedResourceStatus(String glueFileName) {
     });
   }
 
+  @Test
+  void customizeMatcher() {
+    var glue = createGlue("/glue/SimpleNotUseSSA.yaml");
+
+    await().pollDelay(INITIAL_RECONCILE_WAIT_TIMEOUT).untilAsserted(() -> {
+      assertThat(get(ConfigMap.class, "simple-glue-no-ssa-configmap")).isNotNull();
+    });
+    delete(glue);
+    await().pollDelay(INITIAL_RECONCILE_WAIT_TIMEOUT).untilAsserted(() -> {
+      assertThat(get(ConfigMap.class, "simple-glue-no-ssa-configmap")).isNull();
+    });
+  }
+
   private List<Glue> testWorkflowList(int num) {
     List<Glue> res = new ArrayList<>();
     IntStream.range(0, num).forEach(index -> {

src/test/resources/glue/SimpleNotUseSSA.yaml

@@ -0,0 +1,16 @@
+# Invalid GLUE, presents resources with non-unique name
+apiVersion: io.javaoperatorsdk.operator.glue/v1beta1
+kind: Glue
+metadata:
+  name: simple-glue-no-ssa
+spec:
+  childResources:
+    - name: configMap
+      matcher: NONE
+      resource:
+        apiVersion: v1
+        kind: ConfigMap
+        metadata:
+          name: simple-glue-no-ssa-configmap
+        data:
+          key: "value1"