aptly mirror parametrization

PROD-15379

Change-Id: Icff58138405245e968d63539ec7b0df2a313b6fd
diff --git a/aptly/server/mirror/ubuntu/trusty/haproxy.yml b/aptly/server/mirror/ubuntu/trusty/haproxy.yml
index 0b92cb2..ca4c9c5 100644
--- a/aptly/server/mirror/ubuntu/trusty/haproxy.yml
+++ b/aptly/server/mirror/ubuntu/trusty/haproxy.yml
@@ -1,14 +1,19 @@
 parameters:
+  _param:
+    mirror_haproxy-trusty_source: http://ppa.launchpad.net/vbernat/haproxy-1.5/ubuntu
+    mirror_haproxy-trusty_distribution: trusty
+    mirror_haproxy-trusty_components: main
+    mirror_haproxy-trusty_gpgkeys:
+      - 1C61B9CD
   aptly:
     server:
       mirror:
         haproxy-trusty:
-          source: http://ppa.launchpad.net/vbernat/haproxy-1.5/ubuntu
-          distribution: trusty
-          components: main
+          source: ${_param:mirror_haproxy-trusty_source}
+          distribution: ${_param:mirror_haproxy-trusty_distribution}
+          components: ${_param:mirror_haproxy-trusty_components}
           architectures: amd64
-          gpgkeys:
-            - 1C61B9CD
+          gpgkeys: ${_param:mirror_haproxy-trusty_gpgkeys}
           publisher:
             component: haproxy
             distributions: