Fix docker apt-repo for Ubuntu18

roles/docker/tasks/main.yml

@@ -73,7 +73,9 @@
   retries: 4
   delay: "{{ retry_stagger | random + 3 }}"
   with_items: "{{ dockerproject_repo_key_info.repo_keys }}"
-  when: not (ansible_os_family in ["CoreOS", "Container Linux by CoreOS", "RedHat", "Suse"] or is_atomic)
+  when:
+    - not (ansible_os_family in ["CoreOS", "Container Linux by CoreOS", "RedHat", "Suse"] or is_atomic)
+    - use_docker_engine is defined and use_docker_engine
 
 - name: ensure docker-engine repository is enabled
   action: "{{ dockerproject_repo_info.pkg_repo }}"
@@ -81,7 +83,9 @@
     repo: "{{item}}"
     state: present
   with_items: "{{ dockerproject_repo_info.repos }}"
-  when: not (ansible_os_family in ["CoreOS", "Container Linux by CoreOS", "RedHat", "Suse"] or is_atomic) and (dockerproject_repo_info.repos|length > 0)
+  when:
+    - use_docker_engine is defined and use_docker_engine
+    - not (ansible_os_family in ["CoreOS", "Container Linux by CoreOS", "RedHat", "Suse"] or is_atomic) and (dockerproject_repo_info.repos|length > 0)
 
 - name: Configure docker repository on RedHat/CentOS
   template:
@@ -104,6 +108,7 @@
     line: 'obsoletes=0'
   when: ansible_distribution in ["CentOS","RedHat"] and not is_atomic
 
+
 - name: ensure docker packages are installed
   action: "{{ docker_package_info.pkg_mgr }}"
   args:
@@ -111,6 +116,7 @@
     force: "{{item.force|default(omit)}}"
     conf_file: "{{item.yum_conf|default(omit)}}"
     state: present
+    update_cache: yes
   register: docker_task_result
   until: docker_task_result|succeeded
   retries: 4
@@ -118,6 +124,17 @@
   with_items: "{{ docker_package_info.pkgs }}"
   notify: restart docker
   when: not (ansible_os_family in ["CoreOS", "Container Linux by CoreOS"] or is_atomic) and (docker_package_info.pkgs|length > 0)
+  ignore_errors: true
+
+- name: get available packages on Ubuntu
+  command: apt-cache policy docker-ce
+  when: docker_task_result|failed
+  register: available_packages
+
+- name: show available packages on ubuntu
+  fail:
+    msg: "{{available_packages}}"
+  when: docker_task_result|failed
 
 - name: ensure service is started if docker packages are already present
   service: