fix fabric8io#887: adding visiting logic for walking api resources

CHANGELOG.md

@@ -7,6 +7,7 @@
 #### Improvements
 * Fix #4041: adding Quantity.getNumericalAmount with an explanation about bytes and cores.
 * Fix #4241: added more context to informer logs with the endpoint path
+* Fix #887: added KubernetesClient.visitResources to search and perform other operations across all resources.
 
 #### Dependency Upgrade
 

kubernetes-client-api/src/main/java/io/fabric8/kubernetes/client/ApiVisitor.java

@@ -0,0 +1,63 @@
+package io.fabric8.kubernetes.client;
+
+import io.fabric8.kubernetes.api.model.APIResource;
+import io.fabric8.kubernetes.api.model.GenericKubernetesResource;
+import io.fabric8.kubernetes.api.model.GenericKubernetesResourceList;
+import io.fabric8.kubernetes.client.dsl.MixedOperation;
+import io.fabric8.kubernetes.client.dsl.Resource;
+import io.fabric8.kubernetes.client.utils.ApiVersionUtil;
+
+/**
+ * Used to perform operations across all resources known to the api server.
+ */
+public interface ApiVisitor {
+
+  public enum ApiVisitResult {
+    /**
+     * If returned, stop the visiting process immediately
+     */
+    TERMINATE,
+    /**
+     * Continue visiting
+     */
+    CONTINUE,
+    /**
+     * Skip any visiting that would occur under this point
+     */
+    SKIP
+  }
+
+  /**
+   * Visit the api. The core/legacy group will be an empty string.
+   * 
+   * @param api the group name
+   * @return the result to control future actions. {@link ApiVisitResult#SKIP} will skip visiting all versions of this api.
+   */
+  default ApiVisitResult visitApi(String api) {
+    return ApiVisitResult.CONTINUE;
+  }
+
+  /**
+   * Visit the apiVersion, which will be in the form of api/version or just v1 for the core.
+   * Use {@link ApiVersionUtil} to separate components if needed.
+   * 
+   * @return the result to control future actions. {@link ApiVisitResult#SKIP} will skip visiting all resources under this
+   *         apiVersion.
+   */
+  default ApiVisitResult visitApiVersion(String apiVersion) {
+    return ApiVisitResult.CONTINUE;
+  }
+
+  /**
+   * Visit the resource.
+   * 
+   * @param apiVersion in the form of api/version or just v1 for the core
+   * @param apiResource can be used to look at applicable verbs and other resource information
+   * @param operation the {@link GenericKubernetesResource} operation for the current resource. Will be in the namespace of the
+   *        client by default.
+   * @return {@link ApiVisitResult#TERMINATE} to terminate. SKIP and CONTINUE will both continue visiting.
+   */
+  ApiVisitResult visitResources(String apiVersion, APIResource apiResource,
+      MixedOperation<GenericKubernetesResource, GenericKubernetesResourceList, Resource<GenericKubernetesResource>> operation);
+
+}

kubernetes-client-api/src/main/java/io/fabric8/kubernetes/client/KubernetesClient.java

@@ -511,4 +511,11 @@ NamespaceListVisitFromServerGetDeleteRecreateWaitApplicable<HasMetadata> resourc
    * @return {@link NonNamespaceOperation} for RuntimeClass
    */
   NonNamespaceOperation<RuntimeClass, RuntimeClassList, Resource<RuntimeClass>> runtimeClasses();
+
+  /**
+   * Visit all resources with the given {@link ApiVisitor}.
+   * 
+   * @param visitor
+   */
+  void visitResources(ApiVisitor visitor);
 }

kubernetes-client-api/src/main/java/io/fabric8/kubernetes/client/dsl/base/ResourceDefinitionContext.java

@@ -15,11 +15,15 @@
  */
 package io.fabric8.kubernetes.client.dsl.base;
 
+import io.fabric8.kubernetes.api.model.APIResource;
 import io.fabric8.kubernetes.api.model.HasMetadata;
 import io.fabric8.kubernetes.api.model.KubernetesResource;
 import io.fabric8.kubernetes.client.KubernetesClientException;
+import io.fabric8.kubernetes.client.utils.ApiVersionUtil;
 import io.fabric8.kubernetes.client.utils.Utils;
 
+import java.util.Optional;
+
 public class ResourceDefinitionContext {
   protected String group;
   protected boolean namespaced;
@@ -59,18 +63,28 @@ protected void validate() {
   public static ResourceDefinitionContext fromResourceType(Class<? extends KubernetesResource> resource) {
     try {
       return new Builder()
-        .withGroup(HasMetadata.getGroup(resource))
-        .withVersion(HasMetadata.getVersion(resource))
-        .withNamespaced(Utils.isResourceNamespaced(resource))
-        .withPlural(HasMetadata.getPlural(resource))
-        .withKind(HasMetadata.getKind(resource))
-        .build();
+          .withGroup(HasMetadata.getGroup(resource))
+          .withVersion(HasMetadata.getVersion(resource))
+          .withNamespaced(Utils.isResourceNamespaced(resource))
+          .withPlural(HasMetadata.getPlural(resource))
+          .withKind(HasMetadata.getKind(resource))
+          .build();
     } catch (IllegalArgumentException e) {
       throw new KubernetesClientException(
           String.format("%s is not annotated appropriately: %s", resource.getName(), e.getMessage()), e);
     }
   }
 
+  public static ResourceDefinitionContext fromApiResource(String apiVersion, APIResource resource) {
+    return new Builder()
+        .withGroup(Optional.ofNullable(ApiVersionUtil.trimGroupOrNull(apiVersion)).orElse(""))
+        .withVersion(ApiVersionUtil.trimVersion(apiVersion))
+        .withNamespaced(Boolean.TRUE.equals(resource.getNamespaced()))
+        .withPlural(resource.getName())
+        .withKind(resource.getKind())
+        .build();
+  }
+
   public static class Builder {
     private final ResourceDefinitionContext resourceDefinitionContext;
 

kubernetes-client-api/src/test/java/io/fabric8/kubernetes/client/dsl/base/ResourceDefinitionContextTest.java

@@ -16,10 +16,12 @@
 
 package io.fabric8.kubernetes.client.dsl.base;
 
+import io.fabric8.kubernetes.api.model.APIResourceBuilder;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 class ResourceDefinitionContextTest {
 
@@ -31,5 +33,17 @@ void missingRequiredKindShouldFail() {
     ResourceDefinitionContext context = builder.build();
     assertEquals("kinds", context.getPlural());
   }
-
+
+  @Test
+  void fromCoreApiResource() {
+    ResourceDefinitionContext context = ResourceDefinitionContext.fromApiResource("v1",
+        new APIResourceBuilder().withKind("builtin").withName("builtins").withNamespaced(true).build());
+
+    assertEquals("builtins", context.getPlural());
+    assertEquals("builtin", context.getKind());
+    assertTrue(context.isNamespaceScoped());
+    assertEquals("", context.getGroup());
+    assertEquals("v1", context.getVersion());
+  }
+
 }

kubernetes-client/src/main/java/io/fabric8/kubernetes/client/DefaultKubernetesClient.java

@@ -17,6 +17,9 @@
 
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.type.TypeFactory;
+import io.fabric8.kubernetes.api.model.APIGroup;
+import io.fabric8.kubernetes.api.model.APIGroupBuilder;
+import io.fabric8.kubernetes.api.model.APIResource;
 import io.fabric8.kubernetes.api.model.APIService;
 import io.fabric8.kubernetes.api.model.APIServiceList;
 import io.fabric8.kubernetes.api.model.Binding;
@@ -28,6 +31,8 @@
 import io.fabric8.kubernetes.api.model.EndpointsList;
 import io.fabric8.kubernetes.api.model.GenericKubernetesResource;
 import io.fabric8.kubernetes.api.model.GenericKubernetesResourceList;
+import io.fabric8.kubernetes.api.model.GroupVersionForDiscovery;
+import io.fabric8.kubernetes.api.model.GroupVersionForDiscoveryBuilder;
 import io.fabric8.kubernetes.api.model.HasMetadata;
 import io.fabric8.kubernetes.api.model.KubernetesListBuilder;
 import io.fabric8.kubernetes.api.model.KubernetesResourceList;
@@ -64,6 +69,7 @@
 import io.fabric8.kubernetes.api.model.coordination.v1.LeaseList;
 import io.fabric8.kubernetes.api.model.node.v1beta1.RuntimeClass;
 import io.fabric8.kubernetes.api.model.node.v1beta1.RuntimeClassList;
+import io.fabric8.kubernetes.client.ApiVisitor.ApiVisitResult;
 import io.fabric8.kubernetes.client.KubernetesClientBuilder.ExecutorSupplier;
 import io.fabric8.kubernetes.client.dsl.ApiextensionsAPIGroupDSL;
 import io.fabric8.kubernetes.client.dsl.AppsAPIGroupDSL;
@@ -128,7 +134,9 @@
 
 import java.io.InputStream;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
+import java.util.List;
 
 /**
  * Class for Default Kubernetes Client implementing KubernetesClient interface.
@@ -683,4 +691,47 @@ public Client newClient(RequestConfig requestConfig) {
     return result;
   }
 
+  @Override
+  public void visitResources(ApiVisitor visitor) {
+    if (visitGroups(visitor, Arrays.asList(new APIGroupBuilder().withName("")
+        .withVersions(new GroupVersionForDiscoveryBuilder().withGroupVersion("v1").build()).build()))) {
+      return; // user terminated
+    }
+    visitGroups(visitor, getApiGroups().getGroups());
+  }
+
+  private boolean visitGroups(ApiVisitor visitor, List<APIGroup> groups) {
+    for (APIGroup group : groups) {
+      switch (visitor.visitApi(group.getName())) {
+        case TERMINATE:
+          return true;
+        case SKIP:
+          continue;
+        case CONTINUE:
+          for (GroupVersionForDiscovery groupForDiscovery : group.getVersions()) {
+            String groupVersion = groupForDiscovery.getGroupVersion();
+            ApiVisitResult versionResult = visitor.visitApiVersion(groupVersion);
+            switch (versionResult) {
+              case TERMINATE:
+                return true;
+              case SKIP:
+                continue;
+              case CONTINUE:
+                for (APIResource resource : this.getApiResources(groupVersion).getResources()) {
+                  if (resource.getName().contains("/")) { // skip subresources
+                    continue;
+                  }
+                  ApiVisitResult resourceResult = visitor.visitResources(groupVersion, resource,
+                      this.genericKubernetesResources(ResourceDefinitionContext.fromApiResource(groupVersion, resource)));
+                  if (resourceResult == ApiVisitResult.TERMINATE) {
+                    return true;
+                  }
+                }
+            }
+          }
+      }
+    }
+    return false;
+  }
+
 }

kubernetes-itests/src/test/java/io/fabric8/kubernetes/ApiGroupResourceListsIT.java

@@ -18,10 +18,21 @@
 
 import io.fabric8.kubernetes.api.model.APIGroup;
 import io.fabric8.kubernetes.api.model.APIGroupList;
+import io.fabric8.kubernetes.api.model.APIResource;
 import io.fabric8.kubernetes.api.model.APIResourceList;
+import io.fabric8.kubernetes.api.model.GenericKubernetesResource;
+import io.fabric8.kubernetes.api.model.GenericKubernetesResourceList;
+import io.fabric8.kubernetes.client.ApiVisitor;
 import io.fabric8.kubernetes.client.KubernetesClient;
+import io.fabric8.kubernetes.client.dsl.MixedOperation;
+import io.fabric8.kubernetes.client.dsl.Resource;
 import org.junit.jupiter.api.Test;
 
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
@@ -58,4 +69,57 @@ void testApiResources() {
 
     assertTrue(list.getResources().stream().anyMatch(r -> "configmaps".equals(r.getName())));
   }
+
+  @Test
+  void testApiVisiting() {
+    APIGroupList list = client.getApiGroups();
+
+    AtomicInteger groupCount = new AtomicInteger();
+
+    client.visitResources(new ApiVisitor() {
+
+      @Override
+      public ApiVisitResult visitApi(String api) {
+        groupCount.incrementAndGet();
+        return ApiVisitResult.CONTINUE;
+      }
+
+      @Override
+      public ApiVisitResult visitResources(String apiVersion, APIResource apiResource,
+          MixedOperation<GenericKubernetesResource, GenericKubernetesResourceList, Resource<GenericKubernetesResource>> mixedOperation) {
+        return ApiVisitResult.CONTINUE;
+      }
+
+    });
+
+    // visit all groups + the core group
+    assertEquals(list.getGroups().size() + 1, groupCount.get());
+
+    // visit again to make sure we terminate as expected 
+    CompletableFuture<Boolean> done = new CompletableFuture<>();
+    client.visitResources(new ApiVisitor() {
+
+      @Override
+      public ApiVisitResult visitApi(String api) {
+        if (api.isEmpty()) {
+          return ApiVisitResult.CONTINUE;
+        }
+        return ApiVisitResult.TERMINATE;
+      }
+
+      @Override
+      public ApiVisitResult visitResources(String apiVersion, APIResource apiResource,
+          MixedOperation<GenericKubernetesResource, GenericKubernetesResourceList, Resource<GenericKubernetesResource>> operation) {
+        assertFalse(done.isDone());
+        if (apiResource.getName().equals("configmaps")) {
+          done.complete(!operation.inAnyNamespace().list().getItems().isEmpty());
+          return ApiVisitResult.TERMINATE;
+        }
+        return ApiVisitResult.CONTINUE;
+      }
+
+    });
+
+    assertTrue(done.join());
+  }
 }

kubernetes-itests/src/test/java/io/fabric8/kubernetes/PodIT.java

@@ -172,6 +172,15 @@ void log() {
     assertNotNull(log);
   }
 
+  @Test
+  public void execSomething() throws Exception {
+    client.pods().withName("pod-standard").waitUntilReady(POD_READY_WAIT_IN_SECONDS, TimeUnit.SECONDS);
+    ExecWatch exec = client
+        .pods()
+        .withName("pod-standard")
+        .exec("date");
+  }
+
   @Test
   void exec() throws Exception {
     client.pods().withName("pod-standard").waitUntilReady(POD_READY_WAIT_IN_SECONDS, TimeUnit.SECONDS);