Fix docker install on rhel7

roles/docker/tasks/main.yml

@@ -38,6 +38,13 @@
   with_items: "{{ docker_repo_info.repos }}"
   when: docker_repo_info.repos|length > 0
 
+- name: Configure docker repository on RedHat
+  copy:
+    src: "rh_docker.repo"
+    dest: "/etc/yum.repos.d/docker.repo"
+  when: ansible_distribution == "RedHat" and
+        ansible_distribution_major_version > 7
+
 - name: ensure docker packages are installed
   action: "{{ docker_package_info.pkg_mgr }}"
   args:
@@ -53,7 +60,7 @@
     regexp: '^DOCKER_STORAGE_OPTIONS=.*$'
     state: present
     backup: yes
-  when: ansible_os_family == "RedHat"
+  when: ansible_distribution == "CentOS"
 
 - meta: flush_handlers