Make Gerrit system user and group configurable

The gerrit2 system user and group was hardcoded in
manage_projects. This simply allows the values to
be overridden by options 'gerrit-system-user' and
'gerrit-system-group' in the defaults section of the
projects.yml file.

fixes lp 1191542

Change-Id: Ieb736e08a6f96c10abfabe8b17808681732cb8b6
Reviewed-on: https://review.openstack.org/33196
Reviewed-by: Monty Taylor <mordred@inaugust.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Approved: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins
diff --git a/jeepyb/cmd/manage_projects.py b/jeepyb/cmd/manage_projects.py
index 429367c..8da04a9 100644
--- a/jeepyb/cmd/manage_projects.py
+++ b/jeepyb/cmd/manage_projects.py
@@ -299,6 +299,8 @@
     GERRIT_USER = defaults.get('gerrit-user')
     GERRIT_KEY = defaults.get('gerrit-key')
     GERRIT_GITID = defaults.get('gerrit-committer')
+    GERRIT_SYSTEM_USER = defaults.get('gerrit-system-user', 'gerrit2')
+    GERRIT_SYSTEM_GROUP = defaults.get('gerrit-system-group', 'gerrit2')
 
     gerrit = gerritlib.gerrit.Gerrit('localhost',
                                      GERRIT_USER,
@@ -355,8 +357,9 @@
 
                     if not os.path.exists(project_dir):
                         run_command("git --bare init %s" % project_dir)
-                        run_command("chown -R gerrit2:gerrit2 %s"
-                                    % project_dir)
+                        run_command("chown -R %s:%s %s"
+                                    % (GERRIT_SYSTEM_USER, GERRIT_SYSTEM_GROUP,
+                                       project_dir))
 
                     git_command(repo_path,
                                 push_string % remote_url,