restrict rpm query to redhat

roles/docker/tasks/systemd.yml

@@ -13,7 +13,7 @@
 - name: get systemd version
   command: rpm -q --qf '%{V}\n' systemd
   register: systemd_version
-  when: not (ansible_os_family in ["CoreOS", "Container Linux by CoreOS"] or is_atomic)
+  when: ansible_os_family == "RedHat" and not is_atomic
 
 - name: Write docker.service systemd file
   template:

roles/docker/templates/docker.service.j2

@@ -24,7 +24,7 @@ ExecStart={{ docker_bin_dir }}/docker daemon \
           $DOCKER_NETWORK_OPTIONS \
           $DOCKER_DNS_OPTIONS \
           $INSECURE_REGISTRY
-{% if systemd_version.stdout|int >= 226 %}
+{% if ansible_os_family == "RedHat" and systemd_version.stdout|int >= 226 %}
 TasksMax=infinity
 {% endif %}
 LimitNOFILE=1048576