feat: demonstrate contract-first CRDs (#1524)

* feat: demonstrate contract-first CRDs

Modify the leader-election sample to use contract-first. That is,
the CRDs is written in YAML and the java code is generated automatically
using the java-generator-maven-plugin from fabric8.

* Fix custom resource name and plural

* Add status to CRD, ensure reconciledBy is not null, fix ClusterRole

Lots of silly mistakes, sorry for that.

* Use plural form in CRD file name

Author: derlin

sample-operators/leader-election/README.md

@@ -1,6 +1,10 @@
 # Leader Election E2E Test
 
-The purpose of this module is to e2e test leader election feature.
+The purpose of this module is to e2e test leader election feature and to demonstrate contract-first CRDs.
 
 The deployment is using directly pods in order to better control some aspects in test. 
-In real life this would be a Deployment.
+In real life this would be a Deployment.
+
+The custom resource definition (CRD) is defined in YAML in the folder `src/main/resources/kubernetes`.
+Upon build, the [java-generator-maven-plugin](https://github.com/fabric8io/kubernetes-client/blob/master/doc/java-generation-from-CRD.md)
+generates the Java code under `target/generated-sources/java`.

sample-operators/leader-election/k8s/namespace-inferred-operator.yaml

@@ -48,8 +48,8 @@ rules:
   - apiGroups:
       - "sample.javaoperatorsdk"
     resources:
-      - leaderelectiontestcustomresources
-      - leaderelectiontestcustomresources/status
+      - leaderelections
+      - leaderelections/status
     verbs:
       - '*'
   - apiGroups:

sample-operators/leader-election/k8s/operator.yaml

@@ -52,8 +52,8 @@ rules:
   - apiGroups:
       - "sample.javaoperatorsdk"
     resources:
-      - leaderelectiontestcustomresources
-      - leaderelectiontestcustomresources/status
+      - leaderelections
+      - leaderelections/status
     verbs:
       - '*'
   - apiGroups:

sample-operators/leader-election/pom.xml

@@ -47,11 +47,6 @@
             <artifactId>takes</artifactId>
             <version>1.21.1</version>
         </dependency>
-        <dependency>
-            <groupId>io.fabric8</groupId>
-            <artifactId>crd-generator-apt</artifactId>
-            <scope>provided</scope>
-        </dependency>
         <dependency>
             <groupId>org.awaitility</groupId>
             <artifactId>awaitility</artifactId>
@@ -88,6 +83,22 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.10.0</version>
             </plugin>
+            <plugin>
+                <!-- Generate Java code from the custom resource definitions -->
+                <groupId>io.fabric8</groupId>
+                <artifactId>java-generator-maven-plugin</artifactId>
+                <version>${fabric8-client.version}</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>generate</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <source>src/main/resources/kubernetes</source>
+                </configuration>
+            </plugin>
         </plugins>
     </build>
 

sample-operators/leader-election/src/main/java/io/javaoperatorsdk/operator/sample/LeaderElectionTestCustomResource.java

@@ -1,15 +1,19 @@
 package io.javaoperatorsdk.operator.sample;
 
 import java.time.Duration;
+import java.util.ArrayList;
 
 import io.javaoperatorsdk.operator.api.reconciler.Context;
 import io.javaoperatorsdk.operator.api.reconciler.ControllerConfiguration;
 import io.javaoperatorsdk.operator.api.reconciler.Reconciler;
 import io.javaoperatorsdk.operator.api.reconciler.UpdateControl;
 
+import javaoperatorsdk.sample.v1.LeaderElection;
+import javaoperatorsdk.sample.v1.LeaderElectionStatus;
+
 @ControllerConfiguration()
 public class LeaderElectionTestReconciler
-    implements Reconciler<LeaderElectionTestCustomResource> {
+    implements Reconciler<LeaderElection> {
 
   private final String reconcilerName;
 
@@ -18,12 +22,15 @@ public LeaderElectionTestReconciler(String reconcilerName) {
   }
 
   @Override
-  public UpdateControl<LeaderElectionTestCustomResource> reconcile(
-      LeaderElectionTestCustomResource resource,
-      Context<LeaderElectionTestCustomResource> context) {
+  public UpdateControl<LeaderElection> reconcile(
+      LeaderElection resource,
+      Context<LeaderElection> context) {
 
     if (resource.getStatus() == null) {
-      resource.setStatus(new LeaderElectionTestStatus());
+      resource.setStatus(new LeaderElectionStatus());
+    }
+    if (resource.getStatus().getReconciledBy() == null) {
+      resource.getStatus().setReconciledBy(new ArrayList<>());
     }
 
     resource.getStatus().getReconciledBy().add(reconcilerName);

sample-operators/leader-election/src/main/java/io/javaoperatorsdk/operator/sample/LeaderElectionTestReconciler.java

@@ -0,0 +1,34 @@
+# Custom Resource Definition that will be used to generate the Java classes in target/generated-sources/java
+# See https://github.com/fabric8io/kubernetes-client/blob/master/doc/java-generation-from-CRD.md
+# The Java classes will then be used to recreate this CR in target/classes/META-INF/fabric8
+apiVersion: apiextensions.k8s.io/v1
+kind: CustomResourceDefinition
+metadata:
+  name: leaderelections.sample.javaoperatorsdk
+spec:
+  group: sample.javaoperatorsdk
+  names:
+    kind: LeaderElection
+    singular: leaderelection
+    plural: leaderelections
+    shortNames:
+    - le
+    - les
+  scope: Namespaced
+  versions:
+  - name: v1
+    schema:
+      openAPIV3Schema:
+        properties:
+          status:
+            properties:
+              reconciledBy:
+                items:
+                  type: string
+                type: array
+            type: object
+        type: object
+    served: true
+    storage: true
+    subresources:
+      status: {}

sample-operators/leader-election/src/main/java/io/javaoperatorsdk/operator/sample/LeaderElectionTestStatus.java

@@ -27,6 +27,8 @@
 import io.fabric8.kubernetes.client.KubernetesClient;
 import io.fabric8.kubernetes.client.KubernetesClientBuilder;
 
+import javaoperatorsdk.sample.v1.LeaderElection;
+
 import static io.javaoperatorsdk.operator.junit.AbstractOperatorExtension.CRD_READY_WAIT;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.awaitility.Awaitility.await;
@@ -61,7 +63,7 @@ void otherInstancesTakesOverWhenSteppingDown(String yamlFilePrefix) {
     await().pollDelay(Duration.ofSeconds(MINIMAL_SECONDS_FOR_RENEWAL))
         .atMost(Duration.ofSeconds(MAX_WAIT_SECONDS))
         .untilAsserted(() -> {
-          var actualStatus = client.resources(LeaderElectionTestCustomResource.class)
+          var actualStatus = client.resources(LeaderElection.class)
               .inNamespace(namespace).withName(TEST_RESOURCE_NAME).get().getStatus();
 
           assertThat(actualStatus).isNotNull();
@@ -71,14 +73,14 @@ void otherInstancesTakesOverWhenSteppingDown(String yamlFilePrefix) {
 
     client.pods().inNamespace(namespace).withName(OPERATOR_1_POD_NAME).delete();
 
-    var actualListSize = client.resources(LeaderElectionTestCustomResource.class)
+    var actualListSize = client.resources(LeaderElection.class)
         .inNamespace(namespace).withName(TEST_RESOURCE_NAME).get().getStatus().getReconciledBy()
         .size();
 
     await().pollDelay(Duration.ofSeconds(MINIMAL_SECONDS_FOR_RENEWAL))
         .atMost(Duration.ofSeconds(240))
         .untilAsserted(() -> {
-          var actualStatus = client.resources(LeaderElectionTestCustomResource.class)
+          var actualStatus = client.resources(LeaderElection.class)
               .inNamespace(namespace).withName(TEST_RESOURCE_NAME).get().getStatus();
 
           assertThat(actualStatus).isNotNull();
@@ -87,7 +89,7 @@ void otherInstancesTakesOverWhenSteppingDown(String yamlFilePrefix) {
         });
 
     assertReconciliations(
-        client.resources(LeaderElectionTestCustomResource.class).inNamespace(namespace)
+        client.resources(LeaderElection.class).inNamespace(namespace)
             .withName(TEST_RESOURCE_NAME).get().getStatus().getReconciledBy());
   }
 
@@ -104,7 +106,7 @@ private void assertReconciliations(List<String> reconciledBy) {
   }
 
   private void applyCustomResource() {
-    var res = new LeaderElectionTestCustomResource();
+    var res = new LeaderElection();
     res.setMetadata(new ObjectMetaBuilder()
         .withName(TEST_RESOURCE_NAME)
         .withNamespace(namespace)
@@ -150,7 +152,7 @@ private void deployOperatorsInOrder(String yamlFilePrefix) {
 
   void applyCRD() {
     String path =
-        "./target/classes/META-INF/fabric8/leaderelectiontestcustomresources.sample.javaoperatorsdk-v1.yml";
+        "./src/main/resources/kubernetes/leaderelections.sample.javaoperatorsdk-v1.yml";
     try (InputStream is = new FileInputStream(path)) {
       final var crd = client.load(is);
       crd.createOrReplace();