Add user.signingkey to .gitconfig

In an effort to support having an OpenPGP signing key that doesn't
exactly match the name+email in .gitconfig, separately parameterize
the signingkey option allowing it to be explicitly overridden with a
key ID or other similar identifier (such as a matching E-mail
address).

Change-Id: Id577c4479abd2f443f73c630a12e94d3ebe63660

manifests/jenkinsuser.pp

@@ -5,6 +5,7 @@ class jenkins::jenkinsuser(
   $ensure = present,
   $gitfullname = 'OpenStack Jenkins',
   $gitemail = 'jenkins@openstack.org',
+  $gitpgpkey = 'jenkins@openstack.org',
   $gerrituser = 'jenkins',
   $gerritkeytype = 'rsa',
   $gerritkey = undef,

manifests/slave.pp

@@ -5,6 +5,7 @@ class jenkins::slave(
   $user = true,
   $gitfullname = 'OpenStack Jenkins',
   $gitemail = 'jenkins@openstack.org',
+  $gitpgpkey = 'jenkins@openstack.org',
   $gerrituser = 'jenkins',
   $gerritkeytype = 'rsa',
   $gerritkey = undef,
@@ -20,6 +21,7 @@ class jenkins::slave(
       ssh_key       => $ssh_key,
       gitfullname   => $gitfullname,
       gitemail      => $gitemail,
+      gitpgpkey     => $gitpgpkey,
       gerrituser    => $gerrituser,
       gerritkeytype => $gerritkeytype,
       gerritkey     => $gerritkey,

templates/gitconfig.erb

@@ -1,6 +1,7 @@
 [user]
 	name = <%= scope.lookupvar('jenkins::jenkinsuser::gitfullname') %>
 	email = <%= scope.lookupvar('jenkins::jenkinsuser::gitemail') %>
+	signingkey = <%= scope.lookupvar('jenkins::jenkinsuser::gitpgpkey') %>
 [gitreview]
 	rebase = false
 	username = <%= scope.lookupvar('jenkins::jenkinsuser::gerrituser') %>