Add extension point to allow plugins to validate project creation

By implementing this extension point plugins can validate the creation
of new projects based on input arguments. E.g. a plugin could enforce
a certain name scheme for the project names. A more sophisticated
plugin could use this extension point to restrict the project creation
for certain groups to certain folders.

Change-Id: I6b5c69cd435acf9789111d13f31049ef38699215
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

Documentation/config-validation.txt

@@ -32,6 +32,17 @@ are merged to the git repository.
 If the commit fails the validation, the plugin can throw an exception
 which will cause the merge to fail.
 
+[[new-project-validation]]
+== New project validation
+
+
+Plugins implementing the `ProjectCreationValidationListener` interface
+can perform additional validation on project creation based on the
+input arguments.
+
+E.g. a plugin could use this to enforce a certain name scheme for
+project names.
+
 
 GERRIT
 ------

gerrit-server/src/main/java/com/google/gerrit/server/config/GerritGlobalModule.java

@@ -118,6 +118,7 @@ import com.google.gerrit.server.ssh.SshAddressesModule;
 import com.google.gerrit.server.tools.ToolsCatalog;
 import com.google.gerrit.server.util.IdGenerator;
 import com.google.gerrit.server.util.ThreadLocalRequestContext;
+import com.google.gerrit.server.validators.ProjectCreationValidationListener;
 import com.google.inject.Inject;
 import com.google.inject.TypeLiteral;
 import com.google.inject.internal.UniqueAnnotations;
@@ -249,6 +250,7 @@ public class GerritGlobalModule extends FactoryModule {
     DynamicSet.setOf(binder(), ChangeListener.class);
     DynamicSet.setOf(binder(), CommitValidationListener.class);
     DynamicSet.setOf(binder(), MergeValidationListener.class);
+    DynamicSet.setOf(binder(), ProjectCreationValidationListener.class);
     DynamicItem.itemOf(binder(), AvatarProvider.class);
     DynamicSet.setOf(binder(), LifecycleListener.class);
     DynamicSet.setOf(binder(), TopMenu.class);

gerrit-server/src/main/java/com/google/gerrit/server/git/validators/CommitValidationException.java

@@ -14,10 +14,12 @@
 
 package com.google.gerrit.server.git.validators;
 
+import com.google.gerrit.server.validators.ValidationException;
+
 import java.util.Collections;
 import java.util.List;
 
-public class CommitValidationException extends Exception {
+public class CommitValidationException extends ValidationException {
   private static final long serialVersionUID = 1L;
   private final List<CommitValidationMessage> messages;
 

gerrit-server/src/main/java/com/google/gerrit/server/git/validators/MergeValidationException.java

@@ -15,8 +15,9 @@
 package com.google.gerrit.server.git.validators;
 
 import com.google.gerrit.server.git.CommitMergeStatus;
+import com.google.gerrit.server.validators.ValidationException;
 
-public class MergeValidationException extends Exception {
+public class MergeValidationException extends ValidationException {
   private static final long serialVersionUID = 1L;
   private final CommitMergeStatus status;
 

gerrit-server/src/main/java/com/google/gerrit/server/project/CreateProject.java

@@ -20,7 +20,9 @@ import com.google.common.collect.Lists;
 import com.google.gerrit.common.data.GlobalCapability;
 import com.google.gerrit.common.errors.ProjectCreationFailedException;
 import com.google.gerrit.extensions.annotations.RequiresCapability;
+import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.extensions.restapi.BadRequestException;
+import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.extensions.restapi.Response;
 import com.google.gerrit.extensions.restapi.RestModifyView;
 import com.google.gerrit.extensions.restapi.TopLevelResource;
@@ -33,6 +35,8 @@ import com.google.gerrit.server.git.ProjectConfig;
 import com.google.gerrit.server.group.GroupsCollection;
 import com.google.gerrit.server.project.CreateProject.Input;
 import com.google.gerrit.server.project.ProjectJson.ProjectInfo;
+import com.google.gerrit.server.validators.ProjectCreationValidationListener;
+import com.google.gerrit.server.validators.ValidationException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.assistedinject.Assisted;
@@ -67,6 +71,7 @@ public class CreateProject implements RestModifyView<TopLevelResource, Input> {
   private final PerformCreateProject.Factory createProjectFactory;
   private final Provider<ProjectsCollection> projectsCollection;
   private final Provider<GroupsCollection> groupsCollection;
+  private final DynamicSet<ProjectCreationValidationListener> projectCreationValidationListeners;
   private final ProjectJson json;
   private final String name;
 
@@ -74,10 +79,12 @@ public class CreateProject implements RestModifyView<TopLevelResource, Input> {
   CreateProject(PerformCreateProject.Factory performCreateProjectFactory,
       Provider<ProjectsCollection> projectsCollection,
       Provider<GroupsCollection> groupsCollection, ProjectJson json,
+      DynamicSet<ProjectCreationValidationListener> projectCreationValidationListeners,
       @Assisted String name) {
     this.createProjectFactory = performCreateProjectFactory;
     this.projectsCollection = projectsCollection;
     this.groupsCollection = groupsCollection;
+    this.projectCreationValidationListeners = projectCreationValidationListeners;
     this.json = json;
     this.name = name;
   }
@@ -85,7 +92,7 @@ public class CreateProject implements RestModifyView<TopLevelResource, Input> {
   @Override
   public Response<ProjectInfo> apply(TopLevelResource resource, Input input)
       throws BadRequestException, UnprocessableEntityException,
-      ProjectCreationFailedException, IOException {
+      ResourceConflictException, ProjectCreationFailedException, IOException {
     if (input == null) {
       input = new Input();
     }
@@ -129,6 +136,14 @@ public class CreateProject implements RestModifyView<TopLevelResource, Input> {
       throw new BadRequestException(e.getMessage());
     }
 
+    for (ProjectCreationValidationListener l : projectCreationValidationListeners) {
+      try {
+        l.validateNewProject(args);
+      } catch (ValidationException e) {
+        throw new ResourceConflictException(e.getMessage(), e);
+      }
+    }
+
     Project p = createProjectFactory.create(args).createProject();
     return Response.created(json.format(p));
   }

gerrit-server/src/main/java/com/google/gerrit/server/validators/ProjectCreationValidationListener.java

@@ -0,0 +1,35 @@
+// Copyright (C) 2014 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.validators;
+
+import com.google.gerrit.extensions.annotations.ExtensionPoint;
+import com.google.gerrit.server.project.CreateProjectArgs;
+
+/**
+ * Listener to provide validation on project creation.
+ */
+@ExtensionPoint
+public interface ProjectCreationValidationListener {
+  /**
+   * Project creation validation.
+   *
+   * Invoked by Gerrit just before a new project is going to be created.
+   *
+   * @param args arguments for the project creation
+   * @throws ValidationException if validation fails
+   */
+  public void validateNewProject(CreateProjectArgs args)
+      throws ValidationException;
+}

gerrit-server/src/main/java/com/google/gerrit/server/validators/ValidationException.java

@@ -0,0 +1,27 @@
+// Copyright (C) 2014 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.validators;
+
+public class ValidationException extends Exception {
+  private static final long serialVersionUID = 1L;
+
+  public ValidationException(String reason) {
+    super(reason);
+  }
+
+  public ValidationException(String reason, Throwable why) {
+    super(reason, why);
+  }
+}