Add bucklet based build to plugin archetype

If a plugin project is generated with the Maven plugin archetype it
should immediately be buildable with Buck, because Buck is our
preferred build tool for building plugins.

Change-Id: I158dc3df76e4585d9894b0be862aef4d13deb478
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

gerrit-plugin-archetype/src/main/resources/META-INF/maven/archetype-metadata.xml

@@ -58,6 +58,17 @@ limitations under the License.
       </includes>
     </fileSet>
 
+    <fileSet filtered="true">
+      <directory></directory>
+      <include>.buckconfig</include>
+      <include>BUCK</include>
+      <include>VERSION</include>
+      <include>lib/gerrit/BUCK</include>
+      <excludes>
+        <exclude>**/*.java</exclude>
+      </excludes>
+    </fileSet>
+
     <fileSet>
       <directory></directory>
       <includes>

gerrit-plugin-archetype/src/main/resources/archetype-resources/.buckconfig

@@ -0,0 +1,14 @@
+[alias]
+  ${pluginName} = //:${pluginName}
+  plugin = //:${pluginName}
+
+[java]
+  src_roots = java, resources
+
+[project]
+  ignore = .git
+
+[cache]
+  mode = dir
+  dir = buck-out/cache
+

gerrit-plugin-archetype/src/main/resources/archetype-resources/.gitignore

@@ -1,3 +1,7 @@
+/.buckversion
+/.buckd
+/buck-out
+/bucklets
 /target
 /.classpath
 /.project

gerrit-plugin-archetype/src/main/resources/archetype-resources/BUCK

@@ -0,0 +1,22 @@
+include_defs('//bucklets/gerrit_plugin.bucklet')
+
+gerrit_plugin(
+  name = '${pluginName}',
+  srcs = glob(['src/main/java/**/*.java']),
+  resources = glob(['src/main/resources/**/*']),
+  manifest_entries = [
+    'Gerrit-PluginName: ${pluginName}',
+    'Gerrit-ApiType: ${gerritApiType}',
+    'Gerrit-ApiVersion: ${gerritApiVersion}',
+    'Gerrit-Module: ${package}.Module',
+    'Gerrit-SshModule: ${package}.SshModule',
+    'Gerrit-HttpModule: ${package}.HttpModule',
+  ],
+)
+
+# this is required for bucklets/tools/eclipse/project.py to work
+java_library(
+  name = 'classpath',
+  deps = [':${pluginName}__plugin'],
+)
+

gerrit-plugin-archetype/src/main/resources/archetype-resources/VERSION

@@ -0,0 +1,5 @@
+# Used by BUCK to include "Implementation-Version" in plugin Manifest.
+# If this file doesn't exist the output of 'git describe' is used
+# instead.
+PLUGIN_VERSION = '${version}'
+

gerrit-plugin-archetype/src/main/resources/archetype-resources/lib/gerrit/BUCK

@@ -0,0 +1,12 @@
+include_defs('//bucklets/maven_jar.bucklet')
+
+VER = '${gerritApiVersion}'
+REPO = MAVEN_LOCAL
+
+maven_jar(
+  name = '${gerritApiType}-api',
+  id = 'com.google.gerrit:gerrit-${gerritApiType}-api:' + VER,
+  attach_source = False,
+  repository = REPO,
+  license = 'Apache2.0',
+)

gerrit-plugin-archetype/src/main/resources/archetype-resources/src/main/resources/Documentation/build.md

@@ -0,0 +1,79 @@
+Build
+=====
+
+This plugin can be built with Buck or Maven.
+
+Buck
+----
+
+Two build modes are supported: Standalone and in Gerrit tree.
+The standalone build mode is recommended, as this mode doesn't require
+the Gerrit tree to exist locally.
+
+
+### Build standalone
+
+Clone bucklets library:
+
+```
+  git clone https://gerrit.googlesource.com/bucklets
+
+```
+and link it to @PLUGIN@ plugin directory:
+
+```
+  cd @PLUGIN@ && ln -s ../bucklets .
+```
+
+Add link to the .buckversion file:
+
+```
+  cd @PLUGIN@ && ln -s bucklets/buckversion .buckversion
+```
+
+To build the plugin, issue the following command:
+
+
+```
+  buck build plugin
+```
+
+The output is created in
+
+```
+  buck-out/gen/@PLUGIN@.jar
+```
+
+### Build in Gerrit tree
+
+Clone or link this plugin to the plugins directory of Gerrit's source
+tree, and issue the command:
+
+```
+  buck build plugins/@PLUGIN@
+```
+
+The output is created in
+
+```
+  buck-out/gen/plugins/@PLUGIN@/@PLUGIN@.jar
+```
+
+This project can be imported into the Eclipse IDE:
+
+```
+  ./tools/eclipse/project.py
+```
+
+Maven
+-----
+
+Note that the Maven build is provided for compatibility reasons, but
+it is considered to be deprecated and will be removed in a future
+version of this plugin.
+
+To build with Maven, run
+
+```
+mvn clean package
+```