Additional AccountExternalId when creating account

The REST API for creating accounts does only support the creation
of accounts for users stored in Gerrit's internal user store.
The current implementation of CreateAccount only registers an
AccountExternalId of type SCHEME_USERNAME, while for example for
OAuth authentication SCHEME_EXTERNAL is required.

This patch adds a new extension point AccountExternalIdCreator
that can be implemented to inject additional AccountExternalId
entries for an account during account creation.

Change-Id: I53df8ae04a023fd32587136981347bdf176bb4ee
Signed-off-by: Michael Ochmann <michael.ochmann@sap.com>

Documentation/dev-plugins.txt

@@ -1954,6 +1954,32 @@ MySecureStore(@SitePath java.io.File sitePath) {
 No Guice bindings or modules are required. Gerrit will automatically
 discover and bind the implementation.
 
+[[accountcreation]]
+== Account Creation
+
+Plugins can hook into the
+link:rest-api-accounts.html#create-account[account creation] REST API and
+inject additional external identifiers for an account that represents a user
+in some external user store. For that, an implementation of the extension
+point `com.google.gerrit.server.api.accounts.AccountExternalIdCreator`
+must be registered.
+
+[source,java]
+----
+class MyExternalIdCreator implements AccountExternalIdCreator {
+  @Override
+  public List<AccountExternalId> create(Account.Id id, String username,
+      String email) {
+    // your code
+  }
+}
+
+bind(AccountExternalIdCreator.class)
+  .annotatedWith(UniqueAnnotations.create())
+  .to(MyExternalIdCreator.class);
+}
+----
+
 [[download-commands]]
 == Download Commands
 

gerrit-server/src/main/java/com/google/gerrit/server/account/CreateAccount.java

@@ -22,6 +22,7 @@ import com.google.gerrit.common.data.GroupDescriptions;
 import com.google.gerrit.common.errors.InvalidSshKeyException;
 import com.google.gerrit.extensions.annotations.RequiresCapability;
 import com.google.gerrit.extensions.common.AccountInfo;
+import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.DefaultInput;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
@@ -37,6 +38,7 @@ import com.google.gerrit.reviewdb.client.AccountSshKey;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.account.CreateAccount.Input;
+import com.google.gerrit.server.api.accounts.AccountExternalIdCreator;
 import com.google.gerrit.server.group.GroupsCollection;
 import com.google.gerrit.server.ssh.SshKeyCache;
 import com.google.gwtorm.server.OrmDuplicateKeyException;
@@ -48,6 +50,7 @@ import com.google.inject.assistedinject.Assisted;
 import org.apache.commons.validator.routines.EmailValidator;
 
 import java.util.Collections;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 
@@ -74,6 +77,7 @@ public class CreateAccount implements RestModifyView<TopLevelResource, Input> {
   private final AccountCache accountCache;
   private final AccountByEmailCache byEmailCache;
   private final AccountLoader.Factory infoLoader;
+  private final DynamicSet<AccountExternalIdCreator> externalIdCreators;
   private final String username;
   private final AuditService auditService;
 
@@ -82,6 +86,7 @@ public class CreateAccount implements RestModifyView<TopLevelResource, Input> {
       GroupsCollection groupsCollection, SshKeyCache sshKeyCache,
       AccountCache accountCache, AccountByEmailCache byEmailCache,
       AccountLoader.Factory infoLoader,
+      DynamicSet<AccountExternalIdCreator> externalIdCreators,
       @Assisted String username, AuditService auditService) {
     this.db = db;
     this.currentUser = currentUser;
@@ -90,6 +95,7 @@ public class CreateAccount implements RestModifyView<TopLevelResource, Input> {
     this.accountCache = accountCache;
     this.byEmailCache = byEmailCache;
     this.infoLoader = infoLoader;
+    this.externalIdCreators = externalIdCreators;
     this.username = username;
     this.auditService = auditService;
   }
@@ -137,8 +143,14 @@ public class CreateAccount implements RestModifyView<TopLevelResource, Input> {
       }
     }
 
+    LinkedList<AccountExternalId> externalIds = new LinkedList<>();
+    externalIds.add(extUser);
+    for (AccountExternalIdCreator c : externalIdCreators) {
+      externalIds.addAll(c.create(id, username, input.email));
+    }
+
     try {
-      db.accountExternalIds().insert(Collections.singleton(extUser));
+      db.accountExternalIds().insert(externalIds);
     } catch (OrmDuplicateKeyException duplicateKey) {
       throw new ResourceConflictException(
           "username '" + username + "' already exists");

gerrit-server/src/main/java/com/google/gerrit/server/api/accounts/AccountExternalIdCreator.java

@@ -0,0 +1,37 @@
+// Copyright (C) 2016 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.api.accounts;
+
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.AccountExternalId;
+
+import java.util.List;
+
+public interface AccountExternalIdCreator {
+
+  /**
+   * Returns additional external identifiers to assign to a given
+   * user when creating an account.
+   *
+   * @param id the identifier of the account.
+   * @param username the name of the user.
+   * @param email an optional email address to assign to the external
+   * identifiers, or {@code null}.
+   *
+   * @return a list of external identifiers, or an empty list.
+   */
+  public List<AccountExternalId> create(Account.Id id, String username,
+      String email);
+}

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

@@ -69,6 +69,7 @@ import com.google.gerrit.server.account.GroupDetailFactory;
 import com.google.gerrit.server.account.GroupIncludeCacheImpl;
 import com.google.gerrit.server.account.GroupInfoCacheFactory;
 import com.google.gerrit.server.account.GroupMembers;
+import com.google.gerrit.server.api.accounts.AccountExternalIdCreator;
 import com.google.gerrit.server.auth.AuthBackend;
 import com.google.gerrit.server.auth.UniversalAuthBackend;
 import com.google.gerrit.server.avatar.AvatarProvider;
@@ -302,6 +303,7 @@ public class GerritGlobalModule extends FactoryModule {
     DynamicSet.setOf(binder(), ProjectWebLink.class);
     DynamicSet.setOf(binder(), BranchWebLink.class);
     DynamicMap.mapOf(binder(), OAuthLoginProvider.class);
+    DynamicSet.setOf(binder(), AccountExternalIdCreator.class);
 
     factory(UploadValidators.Factory.class);
     DynamicSet.setOf(binder(), UploadValidationListener.class);