feat: inject kube config (#72)

Author: csviri

core/src/main/java/io/javaoperatorsdk/jenvtest/junit/KubeAPIServerExtension.java

@@ -1,6 +1,7 @@
 package io.javaoperatorsdk.jenvtest.junit;
 
 import java.lang.reflect.AnnotatedElement;
+import java.lang.reflect.Field;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Optional;
@@ -26,7 +27,7 @@ public class KubeAPIServerExtension
 
   @Override
   public void beforeAll(ExtensionContext extensionContext) {
-    startIfAnnotationPresent(extensionContext);
+    initialize(extensionContext, true);
   }
 
   @Override
@@ -36,23 +37,69 @@ public void afterAll(ExtensionContext extensionContext) {
 
   @Override
   public void beforeEach(ExtensionContext extensionContext) {
-    startIfAnnotationPresent(extensionContext);
+    initialize(extensionContext, false);
   }
 
   @Override
   public void afterEach(ExtensionContext extensionContext) {
     stopIfAnnotationPresent(extensionContext);
   }
 
-  private void startIfAnnotationPresent(ExtensionContext extensionContext) {
+
+  private void initialize(ExtensionContext extensionContext, boolean staticContext) {
+    var kubeConfigField = getFieldForKubeConfigInjection(extensionContext, staticContext);
+    startIfAnnotationPresent(extensionContext, kubeConfigField.isEmpty());
+    kubeConfigField.ifPresent(f -> setKubeConfigYamlToField(extensionContext, f));
+  }
+
+  private void setKubeConfigYamlToField(ExtensionContext extensionContext, Field kubeConfigField) {
+    try {
+      var target = extensionContext.getTestInstance()
+          .orElseGet(() -> extensionContext.getTestClass().orElseThrow());
+      kubeConfigField.setAccessible(true);
+      kubeConfigField.set(target,
+          kubeApiServer.getKubeConfigYaml());
+    } catch (IllegalAccessException e) {
+      throw new JenvtestException(e);
+    }
+  }
+
+  private Optional<Field> getFieldForKubeConfigInjection(ExtensionContext extensionContext,
+      boolean findStatic) {
+    Class<?> clazz = extensionContext.getTestClass().orElseThrow();
+    var kubeConfigFields = Arrays.stream(clazz.getDeclaredFields())
+        .filter(f -> f.getAnnotationsByType(KubeConfig.class).length > 0)
+        .collect(Collectors.toList());
+    if (kubeConfigFields.isEmpty()) {
+      return Optional.empty();
+    }
+    if (kubeConfigFields.size() > 1) {
+      throw new JenvtestException(
+          "More fields annotation with @" + KubeConfig.class.getSimpleName() + " annotation");
+    }
+    var field = kubeConfigFields.get(0);
+    if (!field.getType().equals(String.class)) {
+      throw new JenvtestException(
+          "Field annotated with @" + KubeConfig.class.getSimpleName() + " is not a String");
+    }
+
+    if (java.lang.reflect.Modifier.isStatic(field.getModifiers()) != findStatic) {
+      return Optional.empty();
+    } else {
+      return Optional.of(field);
+    }
+  }
+
+  private void startIfAnnotationPresent(ExtensionContext extensionContext,
+      boolean updateKubeConfig) {
     extensionContext.getElement().ifPresent(ae -> {
       var annotation = getExtensionAnnotationInstance(ae);
-      annotation.ifPresent(this::startApiServer);
+      annotation.ifPresent(a -> startApiServer(a, updateKubeConfig));
     });
   }
 
-  private void startApiServer(EnableKubeAPIServer annotation) {
-    kubeApiServer = new KubeAPIServer(annotationToConfig(annotation));
+  private void startApiServer(EnableKubeAPIServer annotation, boolean updateKubeConfig) {
+    kubeApiServer = new KubeAPIServer(annotationToConfig(annotation, updateKubeConfig));
     kubeApiServer.start();
   }
 
@@ -64,7 +111,8 @@ private void stopIfAnnotationPresent(ExtensionContext extensionContext) {
     });
   }
 
-  private KubeAPIServerConfig annotationToConfig(EnableKubeAPIServer annotation) {
+  private KubeAPIServerConfig annotationToConfig(EnableKubeAPIServer annotation,
+      boolean updateKubeConfig) {
     var builder = KubeAPIServerConfigBuilder.anAPIServerConfig();
     var version = annotation.kubeAPIVersion();
     if (!NOT_SET.equals(version)) {
@@ -73,6 +121,7 @@ private KubeAPIServerConfig annotationToConfig(EnableKubeAPIServer annotation) {
     if (annotation.apiServerFlags().length > 0) {
       builder.withApiServerFlags(List.of(annotation.apiServerFlags()));
     }
+    builder.withUpdateKubeConfig(updateKubeConfig);
     return builder.build();
   }
 

core/src/main/java/io/javaoperatorsdk/jenvtest/junit/KubeConfig.java

@@ -0,0 +1,16 @@
+package io.javaoperatorsdk.jenvtest.junit;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.*;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+/**
+ * Used to annotate String field in JUnit test to inject Kube Config yaml.
+ */
+@Target({FIELD})
+@Retention(RUNTIME)
+public @interface KubeConfig {
+
+}

samples/src/test/java/io/javaoperatorsdk/jenvtest/JUnitExtensionOnMethodTest.java

@@ -14,4 +14,9 @@ void testCommunication() {
     simpleTest();
   }
 
+  @Test
+  @EnableKubeAPIServer
+  void testCommunication2() {
+    simpleTest();
+  }
 }

samples/src/test/java/io/javaoperatorsdk/jenvtest/JUnitInjectKubeConfigPerTestMethod.java

@@ -0,0 +1,35 @@
+package io.javaoperatorsdk.jenvtest;
+
+import org.junit.jupiter.api.Test;
+
+import io.fabric8.kubernetes.client.Config;
+import io.fabric8.kubernetes.client.KubernetesClientBuilder;
+import io.javaoperatorsdk.jenvtest.junit.EnableKubeAPIServer;
+import io.javaoperatorsdk.jenvtest.junit.KubeConfig;
+
+import static io.javaoperatorsdk.jenvtest.TestUtils.simpleTest;
+
+class JUnitInjectKubeConfigPerTestMethod {
+
+  @KubeConfig
+  String kubeConfigYaml;
+
+  @Test
+  @EnableKubeAPIServer
+  void testCommunication1() {
+    testWithClientFromGeneratedYaml();
+  }
+
+  @Test
+  @EnableKubeAPIServer
+  void testCommunication2() {
+    testWithClientFromGeneratedYaml();
+  }
+
+  private void testWithClientFromGeneratedYaml() {
+    var client = new KubernetesClientBuilder()
+        .withConfig(Config.fromKubeconfig(kubeConfigYaml))
+        .build();
+    simpleTest(client);
+  }
+}

samples/src/test/java/io/javaoperatorsdk/jenvtest/JUnitInjectKubeConfigTest.java

@@ -0,0 +1,38 @@
+package io.javaoperatorsdk.jenvtest;
+
+import org.junit.jupiter.api.Test;
+
+import io.fabric8.kubernetes.client.Config;
+import io.fabric8.kubernetes.client.KubernetesClientBuilder;
+import io.javaoperatorsdk.jenvtest.junit.EnableKubeAPIServer;
+import io.javaoperatorsdk.jenvtest.junit.KubeConfig;
+
+import static io.javaoperatorsdk.jenvtest.TestUtils.simpleTest;
+
+@EnableKubeAPIServer
+class JUnitInjectKubeConfigTest {
+
+  /**
+   * Needs to be static if shared between tests. If present in the test, the "~/kube/config" is not
+   * updated
+   */
+  @KubeConfig
+  static String kubeConfigYaml;
+
+  @Test
+  void testCommunication1() {
+    testWithClientFromGeneratedYaml();
+  }
+
+  @Test
+  void testCommunication2() {
+    testWithClientFromGeneratedYaml();
+  }
+
+  private static void testWithClientFromGeneratedYaml() {
+    var client = new KubernetesClientBuilder()
+        .withConfig(Config.fromKubeconfig(kubeConfigYaml))
+        .build();
+    simpleTest(client);
+  }
+}

samples/src/test/java/io/javaoperatorsdk/jenvtest/TestUtils.java

@@ -33,11 +33,12 @@ public static void simpleTest() {
   }
 
   public static void simpleTest(KubernetesClient client) {
-
     client.resource(TestUtils.testConfigMap()).create();
     var cm = client.resource(TestUtils.testConfigMap()).get();
 
     Assertions.assertThat(cm).isNotNull();
+
+    client.resource(cm).delete();
   }
 
 }