Use local variables for daemon.json template

Instead of using bare lists and dicts this change converts variables
into json for use with daemon.json. jinja2 does have an ability to do
this in side of templates, however it is only available in 2.9+. Until
then the use of ansible's to_json in the playbook is being used.

Refs:
- http://jinja.pocoo.org/docs/2.9/templates/#tojson
- http://docs.ansible.com/ansible/playbooks_filters.html#filters-for-formatting-data

roles/docker/tasks/systemcontainer_docker.yml

@@ -114,6 +114,14 @@
     dest: "{{ docker_systemd_dir }}/custom.conf"
     src: systemcontainercustom.conf.j2
 
+# Set local versions of facts that must be in json format for daemon.json
+# NOTE: When jinja2.9+ is used the daemon.json file can move to using tojson
+- set_fact:
+    l_docker_insecure_registries: "{{ docker_insecure_registries | default([]) | to_json }}"
+    l_docker_log_options: "{{ docker_log_options | default({}) | to_json }}"
+    l_docker_additional_registries: "{{ docker_additional_registries | default([]) | to_json }}"
+    l_docker_blocked_registries: "{{ docker_blocked_registries | default([]) | to_json }}"
+
 # Configure container-engine using the daemon.json file
 - name: Configure Container Engine
   template:

roles/docker/templates/daemon.json

@@ -12,7 +12,7 @@
     "default-gateway": "",
     "default-gateway-v6": "",
     "default-runtime": "oci",
-    "containerd": "/var/run/containerd.sock",
+    "containerd": "/run/containerd.sock",
     "default-ulimits": {},
     "disable-legacy-registry": false,
     "dns": [],
@@ -26,7 +26,7 @@
     "group": "",
     "hosts": [],
     "icc": false,
-    "insecure-registries": {{ docker_insecure_registries|default([]) }},
+    "insecure-registries": {{ l_docker_insecure_registries }},
     "ip": "0.0.0.0",
     "iptables": false,
     "ipv6": false,
@@ -36,9 +36,9 @@
     "live-restore": true,
 {% if docker_log_driver is defined  %}
     "log-driver": "{{ docker_log_driver }}",
-{% endif %}
+{%- endif %}
     "log-level": "",
-    "log-opts": {{ docker_log_options|default({}) }},
+    "log-opts": {{ l_docker_log_options }},
     "max-concurrent-downloads": 3,
     "max-concurrent-uploads": 5,
     "mtu": 0,
@@ -60,7 +60,7 @@
     "tlskey": "",
     "tlsverify": true,
     "userns-remap": "",
-    "add-registry": {{  docker_additional_registries|default([]) }},
-    "blocked-registries": {{ docker_blocked_registries|default([]) }},
+    "add-registry": {{ l_docker_additional_registries }},
+    "blocked-registries": {{ l_docker_blocked_registries }},
     "userland-proxy-path": "/usr/libexec/docker/docker-proxy-current"
 }