add check_mode and tests

plugins/modules/ec2_eip.py

@@ -481,7 +481,7 @@ def ensure_present(
         )
 
     if domain_name:
-        changed, update_reverse_dns_record_result = update_reverse_dns_record_of_eip(client, module, address["AllocationId"], domain_name)
+        changed, update_reverse_dns_record_result = update_reverse_dns_record_of_eip(client, module, address, domain_name)
         result.update({"update_reverse_dns_record_result": update_reverse_dns_record_result})
 
     # Associate address to instance
@@ -529,21 +529,24 @@ def ensure_present(
     return result
 
 
-def update_reverse_dns_record_of_eip(client, module: AnsibleAWSModule, allocation_id, domain_name):
+def update_reverse_dns_record_of_eip(client, module: AnsibleAWSModule, address, domain_name):
     changed = False
 
-    try:
-        update_reverse_dns_record_result = client.modify_address_attribute(
-            AllocationId=allocation_id, DomainName=domain_name
-        )
-        changed = True
-    except AnsibleEC2Error as e:
-        module.fail_json_aws_error(e)
-
-    if "ResponseMetadata" in update_reverse_dns_record_result:
-        del update_reverse_dns_record_result["ResponseMetadata"]
-
-    return changed, camel_dict_to_snake_dict(update_reverse_dns_record_result)
+    if module.check_mode:
+        return True, {}
+    else:
+      try:
+          update_reverse_dns_record_result = client.modify_address_attribute(
+              AllocationId=address["AllocationId"], DomainName=domain_name
+          )
+          changed = True
+      except AnsibleEC2Error as e:
+          module.fail_json_aws_error(e)
+
+      if "ResponseMetadata" in update_reverse_dns_record_result:
+          del update_reverse_dns_record_result["ResponseMetadata"]
+
+      return changed, camel_dict_to_snake_dict(update_reverse_dns_record_result)
 
 
 def main():

tests/integration/targets/ec2_eip/defaults/main.yml

@@ -8,3 +8,4 @@ eip_test_tags:
   AnsibleEIPTestPrefix: "{{ resource_prefix }}"
 eip_info_filters:
   tag:AnsibleEIPTestPrefix: "{{ resource_prefix }}"
+test_domain: test-xyz.com

tests/integration/targets/ec2_eip/tasks/main.yml

@@ -17,6 +17,7 @@
     - ansible.builtin.include_tasks: tasks/release.yml
     - ansible.builtin.include_tasks: tasks/attach_detach_to_eni.yml
     - ansible.builtin.include_tasks: tasks/attach_detach_to_instance.yml
+    - ansible.builtin.include_tasks: tasks/update_reverse_dns_record.yml
 
   always:
     - ansible.builtin.include_tasks: tasks/teardown.yml

tests/integration/targets/ec2_eip/tasks/update_reverse_dns_record.yml

@@ -0,0 +1,43 @@
+- name: Test EIP allocation
+  block:
+    # ------------------------------------------------------------------------------------------
+    # Allocate EIP with reverse DNS record
+    # ------------------------------------------------------------------------------------------
+    - name: Allocate a new EIP and modify it's reverse DNS record - check_mode
+      amazon.aws.ec2_eip:
+        state: present
+        domain_name: "{{ test_domain }}"
+        tags: "{{ eip_test_tags }}"
+      register: eip
+      check_mode: true
+
+    - ansible.builtin.assert:
+        that:
+          - eip is changed
+
+    - name: Ensure no new EIP was created
+      ansible.builtin.include_tasks: tasks/common.yml
+      vars:
+        has_no_new_eip: true
+
+    - name: Allocate a new EIP and modify it's reverse DNS record
+      amazon.aws.ec2_eip:
+        state: present
+        domain_name: "{{ test_domain }}"
+        tags: "{{ eip_test_tags }}"
+      register: eip
+
+    - ansible.builtin.assert:
+        that:
+          - eip is changed
+          - eip.public_ip is defined and ( eip.public_ip | ansible.utils.ipaddr )
+          - eip.allocation_id is defined and eip.allocation_id.startswith("eipalloc-")
+          - eip.update_reverse_dns_record_result is defined
+          - eip.update_reverse_dns_record_result.address.ptr_record_update is defined
+          - eip.update_reverse_dns_record_result.address.ptr_record_update.value == "{{ test_domain }}"
+
+  always:
+    - name: Delete EIP
+      ansible.builtin.include_tasks: tasks/common.yml
+      vars:
+        delete_eips: true