fix #4142: additional patch methods

also correcting the javadocs wrt the patch base item.

removing logic that infers from the passed in item as the context will
already have the necessary information

CHANGELOG.md

@@ -19,6 +19,7 @@
 SharedIndexInformer allows for the addition and removal of indexes even after starting, and you can remove the default namespace index if you wish.
 And Store.getKey can be used rather than directly referencing static Cache functions.
 * Fix #4065: Client.getAPIResources("v1") can be used to obtain the core/legacy resources
+* Fix #4142: Added patch() and patch(PatchContext) methods for use with resource and load
 * Fix #4093: adding a possibility to get a log as an `InputStream` from the `Loggable` resources
 
 #### Dependency Upgrade

doc/MIGRATION-v6.md

@@ -215,6 +215,8 @@ Client.adapt will no longer perform the isAdaptable check - that is you may free
 
 - DSL methods available off of a collection context involving a resource - client.configMaps().create(configMap) - should instead use a no-argument method - client.configMaps().resource(configMap).create() or client.resource(configMap).create().
 
+The only exception to the above is patch(PatchContext, item) - it is valid to be called after withName. 
+
 ## Object Sorting
 
 KubernetesList and Template will no longer automatically sort their objects by default.  You may use the HasMetadataComparator to sort the items as needed.

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

@@ -64,17 +64,19 @@ public interface EditReplacePatchable<T>
 
   /**
    * Update field(s) of a resource using a JSON patch.
-   *
-   * <br>
+   * <p>
    * It is the same as calling {@link #patch(PatchContext, Object)} with {@link PatchType#JSON} specified.
-   *
+   * <p>
    * WARNING: This may overwrite concurrent changes (between when you obtained your item and the current state) in an unexpected
    * way.
-   * Consider using edit instead or ensure you have called load or resource to define the base of your patch
+   * <p>
+   * Consider using edit, which allows for a known base, and a builder instead.
    *
    * @param item to be patched with patched values
    * @return returns deserialized version of api server response
+   * @deprecated use resource(item).patch() or edit instead
    */
+  @Deprecated
   default T patch(T item) {
     return patch(PatchContext.of(PatchType.JSON), item);
   }
@@ -83,8 +85,7 @@ default T patch(T item) {
    * Update field(s) of a resource using type specified in {@link PatchContext}(defaults to strategic merge if not specified).
    *
    * <ul>
-   * <li>{@link PatchType#JSON} - will create a JSON patch against the current item. See the note in {@link #patch(Object)}
-   * about what is used for the base object.
+   * <li>{@link PatchType#JSON} - will create a JSON patch against the latest server state
    * <li>{@link PatchType#JSON_MERGE} - will send the serialization of the item as a JSON MERGE patch.
    * Set the resourceVersion to null to prevent optimistic locking.
    * <li>{@link PatchType#STRATEGIC_MERGE} - will send the serialization of the item as a STRATEGIC MERGE patch.
@@ -137,4 +138,40 @@ default T patch(String patch) {
    * @return updated object
    */
   T patchStatus();
+
+  /**
+   * Update field(s) of a resource using a JSON patch.
+   * <p>
+   * It is the same as calling {@link #patch(PatchContext, Object)} with {@link PatchType#JSON} specified.
+   * <p>
+   * WARNING: This may overwrite concurrent changes (between when you obtained your item and the current state) in an unexpected
+   * way.
+   * <p>
+   * Consider using edit instead.
+   *
+   * @return returns deserialized version of api server response
+   */
+  T patch();
+
+  /**
+   * Update field(s) of a resource using type specified in {@link PatchContext}(defaults to strategic merge if not specified).
+   * <p>
+   * For use when you are providing a complete object to be patched:
+   * resource(item).patch(PatchContext.of(PatchType.SERVER_SIDE_APPLY))
+   *
+   * <ul>
+   * <li>{@link PatchType#JSON} - will create a JSON patch against the latest server state
+   * <li>{@link PatchType#JSON_MERGE} - will send the serialization of the item as a JSON MERGE patch.
+   * Set the resourceVersion to null to prevent optimistic locking.
+   * <li>{@link PatchType#STRATEGIC_MERGE} - will send the serialization of the item as a STRATEGIC MERGE patch.
+   * Set the resourceVersion to null to prevent optimistic locking.
+   * <li>{@link PatchType#SERVER_SIDE_APPLY} - will send the serialization of the item as a SERVER SIDE APPLY patch.
+   * You may explicitly set the {@link PatchContext#getFieldManager()} as well to override the default.
+   * </ul>
+   *
+   * @param patchContext {@link PatchContext} for patch request
+   * @return returns deserialized version of api server response
+   */
+  T patch(PatchContext patchContext);
+
 }

kubernetes-client-api/src/main/java/io/fabric8/kubernetes/client/extension/ResourceAdapter.java

@@ -291,4 +291,14 @@ public T patchStatus() {
     return resource.patchStatus();
   }
 
+  @Override
+  public T patch() {
+    return resource.patch();
+  }
+
+  @Override
+  public T patch(PatchContext patchContext) {
+    return resource.patch(patchContext);
+  }
+
 }

kubernetes-client/src/main/java/io/fabric8/kubernetes/client/dsl/internal/BaseOperation.java

@@ -516,7 +516,25 @@ public T patchStatus(T item) {
 
   @Override
   public T patchStatus() {
-    throw new KubernetesClientException(READ_ONLY_UPDATE_EXCEPTION_MESSAGE);
+    return patchStatus(getNonNullItem());
+  }
+
+  @Override
+  public T patch() {
+    return patch(getNonNullItem());
+  }
+
+  @Override
+  public T patch(PatchContext patchContext) {
+    return patch(patchContext, getNonNullItem());
+  }
+
+  protected T getNonNullItem() {
+    T result = getItem();
+    if (result == null) {
+      throw new KubernetesClientException("item required");
+    }
+    return result;
   }
 
   @Override
@@ -1045,7 +1063,7 @@ public ExtensibleResource<T> dryRun() {
 
   @Override
   public ExtensibleResource<T> lockResourceVersion() {
-    return lockResourceVersion(KubernetesResourceUtil.getResourceVersion(getItem()));
+    return lockResourceVersion(KubernetesResourceUtil.getResourceVersion(getNonNullItem()));
   }
 
   @Override
@@ -1055,7 +1073,7 @@ public T updateStatus(T item) {
 
   @Override
   public T create() {
-    return create(getItem());
+    return create(getNonNullItem());
   }
 
 }

kubernetes-client/src/main/java/io/fabric8/kubernetes/client/dsl/internal/HasMetadataOperation.java

@@ -90,15 +90,6 @@ public T edit(Visitor... visitors) {
    * Will always return non-null or throw an exception.
    */
   protected T requireFromServer() {
-    return requireFromServer(null);
-  }
-
-  /**
-   * Get the current item from the server, consulting the metadata for the name if needed
-   * <br>
-   * Will always return non-null or throw an exception.
-   */
-  protected T requireFromServer(ObjectMeta metadata) {
     try {
       if (Utils.isNotNullOrEmpty(getName())) {
         return newInstance(context.withItem(null)).require();
@@ -109,9 +100,6 @@ protected T requireFromServer(ObjectMeta metadata) {
           return newInstance(context.withItem(null)).withName(name).require();
         }
       }
-      if (metadata != null && Utils.isNotNullOrEmpty(metadata.getName())) {
-        return newInstance(context.withItem(null)).withName(metadata.getName()).require();
-      }
     } catch (ResourceNotFoundException e) {
       if (e.getCause() instanceof KubernetesClientException) {
         throw (KubernetesClientException) e.getCause();
@@ -155,7 +143,7 @@ protected T replace(T item, boolean status) {
     if (!status) {
       try {
         ObjectMeta metadata = item.getMetadata();
-        item = modifyItemForReplaceOrPatch(() -> requireFromServer(metadata), item);
+        item = modifyItemForReplaceOrPatch(() -> requireFromServer(), item);
       } catch (Exception e) {
         throw KubernetesClientException.launderThrowable(forOperationType(REPLACE_OPERATION), e);
       }
@@ -170,7 +158,7 @@ protected T replace(T item, boolean status) {
           // if a resourceVersion is already there, try it first
           resourceVersion = existingResourceVersion;
         } else {
-          T got = requireFromServer(item.getMetadata());
+          T got = requireFromServer();
           resourceVersion = KubernetesResourceUtil.getResourceVersion(got);
         }
 
@@ -207,7 +195,7 @@ protected T replace(T item, boolean status) {
 
   protected T patch(PatchContext context, T base, T item, boolean status) {
     if (base == null && context != null && context.getPatchType() == PatchType.JSON) {
-      base = requireFromServer(item.getMetadata());
+      base = getMandatory();
       if (base.getMetadata() != null) {
         // prevent the resourceVersion from being modified in the patch
         if (item.getMetadata() == null) {
@@ -233,11 +221,6 @@ protected T patch(PatchContext context, T base, T item, boolean status) {
     return visitor.apply(item);
   }
 
-  @Override
-  public T patchStatus() {
-    return patchStatus(getItem());
-  }
-
   @Override
   public T patchStatus(T item) {
     return patch(PatchContext.of(PatchType.JSON_MERGE), null, clone(item), true);

kubernetes-tests/src/test/java/io/fabric8/kubernetes/client/mock/ConfigMapCrudTest.java

@@ -115,6 +115,31 @@ void testCrud() {
     assertEquals("THREE", configmap2.getData().get("III"));
   }
 
+  @Test
+  void testPatchBase() {
+    ConfigMap configmap2 = new ConfigMapBuilder()
+        .withNewMetadata()
+        .addToLabels("foo", "bar")
+        .withName("configmap2")
+        .endMetadata()
+        .addToData("two", "2")
+        .build();
+    ConfigMap configmap2a = new ConfigMapBuilder()
+        .withNewMetadata()
+        .addToLabels("foo", "bar")
+        .withName("configmap2")
+        .endMetadata()
+        .addToData("three", "3")
+        .build();
+
+    client.configMaps().inNamespace("ns1").resource(configmap2).create();
+    client.configMaps().inNamespace("ns1").resource(configmap2a).replace();
+
+    // should still diff to latest
+    ConfigMap result = client.configMaps().inNamespace("ns1").resource(configmap2).patch(configmap2);
+    assertEquals(Collections.singletonMap("three", "3"), result.getData());
+  }
+
   @Test
   @DisplayName("edit, should add and remove data entries")
   void edit() {