Fix: for 18.09.x

- add an override for docker.service (param -H fd://) conflicts qith /etc/docker/daemon.json
 - refactor code to "with_items" for containerd/docker

tasks/docker-1809-shim.yml

@@ -1,13 +1,19 @@
 ---
-- name: Ensure containerd service dir exists.
+- name: Ensure service directories exist.
   file:
-    path: /etc/systemd/system/containerd.service.d
+    path: /etc/systemd/system/{{ item }}
     state: directory
+  with_items:
+    - containerd.service.d
+    - docker.service.d
 
-- name: Add shim to ensure Docker can start in all environments.
+- name: Add overrides.
   template:
-    src: override.conf.j2
+    src: "override-{{ item }}.conf.j2"
-    dest: /etc/systemd/system/containerd.service.d/override.conf
+    dest: /etc/systemd/system/{{ item }}.service.d/override.conf
+  with_items:
+    - containerd
+    - docker
   register: override_template
 
 - name: Reload systemd daemon if template is changed.

templates/override-docker.conf.j2

@@ -0,0 +1,4 @@
+# {{ ansible_managed }}
+[Service]
+ExecStart=
+ExecStart=/usr/bin/dockerd