docker_swarm_service: Compare image by digest (#51134)

* Compare image by digest

* Add changelog fragment

* Fix version check

* Remove unused import

* Add note about image resolving

* Don’t overwrite image

* Fix documentation error

* Add resolve_image option

* Add version_added

* Remove whitespace

* Remove unused attribute

* Remove unused attribute

test/integration/targets/docker_swarm_service/tasks/tests/misc.yml

@@ -86,10 +86,14 @@
         published_port: 60001
         target_port: 60001
 
+- name: fake image key as it is not predictable
+  set_fact:
+    ansible_docker_service_output: "{{ output.ansible_docker_service|combine({'image': 'busybox'}) }}"
+
 - name: assert service matches expectations
   assert:
     that:
-      - output.ansible_docker_service == service_expected_output
+      - ansible_docker_service_output == service_expected_output
 
 - name: delete sample service
   register: output

test/integration/targets/docker_swarm_service/tasks/tests/options.yml

@@ -1269,6 +1269,43 @@
       - reserve_memory_2 is not changed
       - reserve_memory_3 is changed
 
+###################################################################
+# resolve_image ###################################################
+###################################################################
+
+- name: resolve_image (false)
+  docker_swarm_service:
+    name: "{{ service_name }}"
+    image: alpine:3.8
+    resolve_image: false
+  register: resolve_image_1
+
+- name: resolve_image (false idempotency)
+  docker_swarm_service:
+    name: "{{ service_name }}"
+    image: alpine:3.8
+    resolve_image: false
+  register: resolve_image_2
+
+- name: resolve_image (change)
+  docker_swarm_service:
+    name: "{{ service_name }}"
+    image: alpine:3.8
+    resolve_image: true
+  register: resolve_image_3
+
+- name: cleanup
+  docker_swarm_service:
+    name: "{{ service_name }}"
+    state: absent
+  diff: no
+
+- assert:
+    that:
+      - resolve_image_1 is changed
+      - resolve_image_2 is not changed
+      - resolve_image_3 is changed
+
 ###################################################################
 # restart_policy ##################################################
 ###################################################################