Change hardcoded nightly repo to variable

Change-Id: Ifbe7369ddc2937f8abd406eb7097a67d5373c863
diff --git a/aptly/server/mirror/ubuntu/xenial/docker.yml b/aptly/server/mirror/ubuntu/xenial/docker.yml
index 819de76..4334374 100644
--- a/aptly/server/mirror/ubuntu/xenial/docker.yml
+++ b/aptly/server/mirror/ubuntu/xenial/docker.yml
@@ -1,4 +1,6 @@
 parameters:
+  _param:
+    apt_mk_version: stable
   aptly:
     server:
       mirror:
@@ -12,4 +14,4 @@
           publisher:
             component: docker
             distributions:
-              - ubuntu-xenial/nightly
+              - ubuntu-xenial/${_param:apt_mk_version}
diff --git a/aptly/server/mirror/ubuntu/xenial/glusterfs.yml b/aptly/server/mirror/ubuntu/xenial/glusterfs.yml
index f8177a0..248de32 100644
--- a/aptly/server/mirror/ubuntu/xenial/glusterfs.yml
+++ b/aptly/server/mirror/ubuntu/xenial/glusterfs.yml
@@ -1,5 +1,6 @@
 parameters:
   _param:
+    apt_mk_version: stable
     glusterfs_version: 3.8
   aptly:
     server:
@@ -14,4 +15,4 @@
           publisher:
             component: glusterfs
             distributions:
-              - ubuntu-xenial/nightly
+              - ubuntu-xenial/${_param:apt_mk_version}
diff --git a/aptly/server/mirror/ubuntu/xenial/grafana.yml b/aptly/server/mirror/ubuntu/xenial/grafana.yml
index 2db0586..8dbb6ea 100644
--- a/aptly/server/mirror/ubuntu/xenial/grafana.yml
+++ b/aptly/server/mirror/ubuntu/xenial/grafana.yml
@@ -1,4 +1,6 @@
 parameters:
+  _param:
+    apt_mk_version: stable
   aptly:
     server:
       mirror:
@@ -12,4 +14,4 @@
           publisher:
             component: grafana
             distributions:
-              - ubuntu-xenial/nightly
+              - ubuntu-xenial/${_param:apt_mk_version}
diff --git a/aptly/server/mirror/ubuntu/xenial/influxdb.yml b/aptly/server/mirror/ubuntu/xenial/influxdb.yml
index 87930b9..a2ac597 100644
--- a/aptly/server/mirror/ubuntu/xenial/influxdb.yml
+++ b/aptly/server/mirror/ubuntu/xenial/influxdb.yml
@@ -1,4 +1,6 @@
 parameters:
+  _param:
+    apt_mk_version: stable
   aptly:
     server:
       mirror:
@@ -12,4 +14,4 @@
           publisher:
             component: influxdb
             distributions:
-              - ubuntu-xenial/nightly
+              - ubuntu-xenial/${_param:apt_mk_version}
diff --git a/aptly/server/mirror/ubuntu/xenial/maas.yml b/aptly/server/mirror/ubuntu/xenial/maas.yml
index 1382a09..0e4a559 100644
--- a/aptly/server/mirror/ubuntu/xenial/maas.yml
+++ b/aptly/server/mirror/ubuntu/xenial/maas.yml
@@ -1,4 +1,6 @@
 parameters:
+  _param:
+    apt_mk_version: stable
   aptly:
     server:
       mirror:
@@ -12,4 +14,4 @@
           publisher:
             component: maas
             distributions:
-              - xenial/nightly
+              - xenial/${_param:apt_mk_version}
diff --git a/aptly/server/mirror/ubuntu/xenial/salt.yml b/aptly/server/mirror/ubuntu/xenial/salt.yml
index 9a9b34c..a100bde 100644
--- a/aptly/server/mirror/ubuntu/xenial/salt.yml
+++ b/aptly/server/mirror/ubuntu/xenial/salt.yml
@@ -1,4 +1,6 @@
 parameters:
+  _param:
+    apt_mk_version: stable
   aptly:
     server:
       mirror:
@@ -12,4 +14,4 @@
           publisher:
             component: salt
             distributions:
-              - ubuntu-xenial/nightly
+              - ubuntu-xenial/${_param:apt_mk_version}