Fix linting issues for ansible-lint 3.4.1

Preparing this role for the ansible-lint version bump

Change-Id: I45f923ffcb26efd85cdde73d096993e08132706a

tasks/main.yml

@@ -26,6 +26,7 @@
 
 - name: Check init system
   command: cat /proc/1/comm
+  changed_when: false
   register: _pid1_name
   tags:
     - always

tasks/rabbitmq_cluster_create.yml

@@ -23,8 +23,8 @@
     - rabbitmq-cluster
 
 - name: Create rabbitmq cluster
-  shell: |
-    rabbitmqctl set_cluster_name {{ rabbitmq_cluster_name }}
+  command: rabbitmqctl set_cluster_name {{ rabbitmq_cluster_name }}
+  changed_when: false
   when: rabbitmq_cluster_status.rc != 0
   tags:
     - rabbitmq-cluster

tasks/rabbitmq_cluster_join.yml

@@ -35,8 +35,9 @@
     - rabbitmq-cluster
 
 - name: Join rabbitmq cluster
-  shell: |
+  command: >
     rabbitmqctl join_cluster "rabbit@{{ rabbitmq_primary_cluster_node.split('.')[0] }}"
+  changed_when: false
   when: result.rc != 0
   register: rabbit_join_cluster
   until: rabbit_join_cluster|success
@@ -46,8 +47,8 @@
     - rabbitmq-cluster
 
 - name: Start rabbitmq app
-  shell: |
-    rabbitmqctl start_app
+  command: rabbitmqctl start_app
+  changed_when: false
   when: result.rc != 0
   tags:
     - rabbitmq-start-app

tasks/rabbitmq_post_install.yml

@@ -76,6 +76,8 @@
     - rabbit_resource_limit_changed|changed
   tags:
     - rabbitmq-config
+    # don't trigger ANSIBLE0016
+    - skip_ansible_lint
 
 - include: rabbitmq_restart.yml
   static: no

tasks/rabbitmq_set_cookie.yml

@@ -14,7 +14,7 @@
 # limitations under the License.
 
 - name: Read rabbit cookie
-  shell: "cat /var/lib/rabbitmq/.erlang.cookie"
+  command: "cat /var/lib/rabbitmq/.erlang.cookie"
   register: tmp_rabbit_cookie
   changed_when: tmp_rabbit_cookie.rc != 0
   failed_when: false

tasks/rabbitmq_upgrade_prep.yml

@@ -28,6 +28,7 @@
 - name: Ensure erlang epmd is stopped
   shell: |
     pkill $(pgrep -lf "erlang" | awk '{print $2}')
+  changed_when: false
   failed_when: false
   tags:
     - rabbitmq-upgrade