Add a REST API endpoint for getting project configuration

To start, only expose the inheritable booleans stored in the project
config, and only to users who can see refs/meta/config.

Change-Id: I299a5317fb641e84b899f8240764c4902a34c72a

Documentation/rest-api-projects.txt

@@ -408,6 +408,41 @@ link:#repository-statistics-info[RepositoryStatisticsInfo] entity.
   }
 ----
 
+[[get-config]]
+Get Config
+~~~~~~~~~~
+[verse]
+'GET /projects/link:#project-name[\{project-name\}]/config'
+
+Gets some configuration information about a project. Note that this
+config info is not simply the contents of `project.config`; it generally
+contains fields that may have been inherited from parent projects.
+
+.Request
+----
+  GET /projects/myproject/config
+----
+
+A link:#config-info[ConfigInfo] entity is returned that describes the
+project configuration. Some fields are only visible to users that have
+read access to `refs/meta/config`.
+
+.Response
+----
+  HTTP/1.1 200 OK
+  Content-Disposition: attachment
+  Content-Type: application/json;charset=UTF-8
+
+  )]}'
+  {
+    "kind": "gerritcodereview#project_config",
+    "use_contributor_agreements": false,
+    "use_content_merge": true,
+    "use_signed_off_by": false,
+    "require_change_id": true
+  }
+----
+
 [[run-gc]]
 Run GC
 ~~~~~~
@@ -896,6 +931,35 @@ statistics of a Git repository.
 |`size_of_packed_objects`  |Size of packed objects in bytes.
 |======================================
 
+[[config-info]]
+ConfigInfo
+~~~~~~~~~~
+The `ConfigInfo` entity contains information about the effective project
+configuration.
+
+Fields marked with * are only visible to users who have read access to
+`refs/meta/config`.
+
+[options="header",width="50%",cols="1,6"]
+|======================================
+|Field Name                   |Description
+|`use_contributor_agreements*`|
+If set, authors must complete a contributor agreement on the site
+before pushing any commits or changes to this project.
+|`use_content_merge*`|
+If set, Gerrit will try to perform a 3-way merge of text file content
+when a file has been modified by both the destination branch and the
+change being submitted. This option only takes effect if submit type is
+not FAST_FORWARD_ONLY.
+|`use_signed_off_by*`|
+If set, each change must contain a Signed-off-by line from either the
+author or the uploader in the commit message.
+|`require_change_id*`|
+If set, require a valid link:user-changeid.html[Change-Id] footer in any
+commit uploaded for review. This does not apply to commits pushed
+directly to a branch or tag.
+|======================================
+
 
 GERRIT
 ------

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

@@ -0,0 +1,44 @@
+// Copyright (C) 2013 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.project;
+
+import com.google.gerrit.extensions.restapi.RestReadView;
+import com.google.gerrit.server.git.GitRepositoryManager;
+
+public class GetConfig implements RestReadView<ProjectResource> {
+  public static class ConfigInfo {
+    public final String kind = "gerritcodereview#project_config";
+
+    public Boolean useContributorAgreements;
+    public Boolean useContentMerge;
+    public Boolean useSignedOffBy;
+    public Boolean requireChangeId;
+  }
+
+  @Override
+  public ConfigInfo apply(ProjectResource resource) {
+    ConfigInfo result = new ConfigInfo();
+    RefControl refConfig = resource.getControl()
+        .controlForRef(GitRepositoryManager.REF_CONFIG);
+    ProjectState project = resource.getControl().getProjectState();
+    if (refConfig.isVisible()) {
+      result.useContributorAgreements = project.isUseContributorAgreements();
+      result.useContentMerge = project.isUseContentMerge();
+      result.useSignedOffBy = project.isUseSignedOffBy();
+      result.requireChangeId = project.isRequireChangeID();
+    }
+    return result;
+  }
+}

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

@@ -51,5 +51,7 @@ public class Module extends RestApiModule {
     put(DASHBOARD_KIND).to(SetDashboard.class);
     delete(DASHBOARD_KIND).to(DeleteDashboard.class);
     install(new FactoryModuleBuilder().build(CreateProject.Factory.class));
+
+    get(PROJECT_KIND, "config").to(GetConfig.class);
   }
 }