Add jenkins job to build gerrit plugins

There currently is no repository for non-core gerrit plugins so there isn't a way to
consume gerrit plugin binaries[1].  We need to build the binary from source so that it is
available for us to install into our gerrit deployment.  This change adds a periodic job
to build gerrit plugins.

[1] https://groups.google.com/d/msg/repo-discuss/M5eVf40B1MU/bj0wUa-dZFEJ

Partial-Bug: #1082781
Change-Id: Ibd915d26baff9d6c7ca376c55b66252f3061494f

modules/openstack_project/files/jenkins_job_builder/config/gerrit-plugin-jobs.yaml

@@ -0,0 +1,41 @@
+
+- job-template:
+    name: 'periodic-gerrit-plugin-{name}'
+    node: '{node}'
+
+    wrappers:
+      - timeout:
+          timeout: 30
+          fail: true
+      - timestamps
+
+    builders:
+      - shell: |
+          #!/bin/bash -xe
+          rm -rf gerrit
+          git clone -b {gerrit-branch} {gerrit-project}
+          git clone -b {plugin-branch} {plugin-project} gerrit/plugins/{plugin-name}
+          cd gerrit/plugins/{plugin-name}
+          /usr/local/jenkins/slave_scripts/maven-properties.sh
+      - inject:
+          properties-file: gerrit/plugins/{plugin-name}/maven.properties
+      - install-buck
+      - shell: |
+          #!/bin/bash -xe
+          export PATH=`pwd`/buck/bin:$PATH
+          cd gerrit
+          buck clean
+          buck build plugins/{plugin-name}:{plugin-name}
+          cp gerrit/buck-out/gen/plugins/{plugin-name}/{plugin-name}.jar gerrit/buck-out/gen/plugins/{plugin-name}/{plugin-name}-$PROJECT_VER.jar
+
+    publishers:
+      - war:
+          site: '{tarball-site}'
+          warfile: 'gerrit/buck-out/gen/plugins/{plugin-name}/{plugin-name}-${{PROJECT_VER}}.jar'
+          target: 'tarballs/ci/{name}'
+      - console-log
+
+- job-group:
+    name: gerrit-plugin-jobs
+    jobs:
+      - 'periodic-gerrit-plugin-{name}'

modules/openstack_project/files/jenkins_job_builder/config/projects.yaml

@@ -494,6 +494,19 @@
     jobs:
       - maven-plugin-jobs
 
+- project:
+    name: javamelody-gerrit-plugin
+    node: bare-precise
+    tarball-site: tarballs.openstack.org
+    gerrit-project: https://git.openstack.org/openstack-infra/gerrit
+    gerrit-branch: openstack/2.8.3
+    plugin-project: https://gerrit.googlesource.com/plugins/javamelody
+    plugin-name: javamelody
+    plugin-branch: stable-2.8
+
+    jobs:
+      - gerrit-plugin-jobs
+
 - project:
     name: zmq-event-publisher
     github-org: openstack-infra

modules/openstack_project/files/zuul/layout.yaml

@@ -2636,6 +2636,8 @@ projects:
     post:
       - gerrit-package
       - gerrit-package-buck
+    periodic:
+      - periodic-gerrit-plugin-javamelody-gerrit-plugin
 
   - name: openstack-infra/gerrit-powered-agenda
     check: