Use apt_repository update_cache feature

With ansible 2.2, apt_repository update_cache feature has
been fixed. When a new repo will be added, apt-get update
will be run after the addition if update_cache is set to yes.

This combined with the apt module now properly checking the
cache validity, we can now have proper updating of the cache
with registering variables.

Change-Id: Ic9788156a88223dc0d27fafa2a798f396135f990

cluster_metrics/playbook-grafana.yml

@@ -53,6 +53,7 @@
       apt_repository:
         repo: "deb https://packagecloud.io/grafana/stable/debian/ wheezy main"
         state: "present"
+        update_cache: yes
     - name: Install grafana
       apt:
         pkg: "grafana"

cluster_metrics/playbook-influx-db.yml

@@ -34,6 +34,7 @@
       apt_repository:
         repo: "deb https://repos.influxdata.com/{{ ansible_distribution | lower }} {{ ansible_distribution_release }} stable"
         state: "present"
+        update_cache: yes
     - name: Install influxdb
       apt:
         pkg: "influxdb"

cluster_metrics/playbook-influx-telegraf.yml

@@ -26,6 +26,7 @@
       apt_repository:
         repo: "deb https://repos.influxdata.com/{{ ansible_distribution | lower }} {{ ansible_distribution_release }} stable"
         state: "present"
+        update_cache: yes
     - name: Install telegraf
       apt:
         pkg: "telegraf"

cluster_metrics/playbook-kapacitor.yml

@@ -22,6 +22,7 @@
       apt_repository:
         repo: "deb https://repos.influxdata.com/{{ ansible_distribution | lower }} {{ ansible_distribution_release }} stable"
         state: "present"
+        update_cache: yes
     - name: Install kapacitor
       apt:
         pkg: "kapacitor"