Allow to specify docker storage driver

inventory/group_vars/all.yml

@@ -157,6 +157,10 @@ docker_daemon_graph: "/var/lib/docker"
 ## to self hosted registries like so:
 docker_options: "--insecure-registry={{ kube_service_addresses }} --graph={{ docker_daemon_graph }}"
 
+## Uncomment this if you want to force overlay/overlay2 as docker storage driver
+## Please note that overlay2 is only supported on newer kernels
+#docker_storage_options: -s overlay2
+
 # K8s image pull policy (imagePullPolicy)
 k8s_image_pull_policy: IfNotPresent
 

roles/docker/templates/docker.service.j2

@@ -11,6 +11,9 @@ Wants=docker.socket
 
 [Service]
 Type=notify
+{% if docker_storage_options is defined %}
+Environment="DOCKER_STORAGE_OPTIONS={{docker_storage_options}}"
+{% endif %}
 Environment=GOTRACEBACK=crash
 ExecReload=/bin/kill -s HUP $MAINPID
 Delegate=yes