Merge branch '64-ensure-netfilter-persistent-is-installed' into 'master'

Resolve "Ensure netfilter-persistent is installed"

Closes #64

See merge request openappstack/bootstrap!31

ansible/roles/prepare_node/tasks/docker.yml

@@ -4,7 +4,6 @@
   apt:
     name:
       - "apt-transport-https"
-    update_cache: true
   become: true
 
 - name: Install docker apt repo key

ansible/roles/prepare_node/tasks/main.yml

@@ -19,6 +19,13 @@
     jump: "ACCEPT"
   become: true
 
+- name: Make sure netfilter-persistent is installed
+  apt:
+    name:
+      - "netfilter-persistent"
+    update_cache: true
+  become: true
+
 - name: Save changes to iptables rules
   shell: netfilter-persistent save
   become: true