ec2_instance - Fix NoneType error on no input tags (#856)

ec2_instance - Fix NoneType error on no input tags

SUMMARY
Reverts bug introduced in #849 which throws a NoneType exception when tags are not input
ISSUE TYPE

Bugfix Pull Request

COMPONENT NAME
ec2_instance
ADDITIONAL INFORMATION
The error gets thrown when trying to wrap dict(None). See https://ansible.softwarefactory-project.io/zuul/build/5e37b5947f7045c6bf01e88f8ae5271f
TASK [elb_classic_lb : Wait for instance a] ************************************
task path: /home/zuul/.ansible/collections/ansible_collections/amazon/aws/tests/integration/targets/elb_classic_lb/tasks/simple_instances.yml:18
Using module file /home/zuul/.ansible/collections/ansible_collections/amazon/aws/plugins/modules/ec2_instance.py
Pipelining is enabled.
<testhost> ESTABLISH LOCAL CONNECTION FOR USER: zuul
<testhost> EXEC /bin/sh -c 'ANSIBLE_DEBUG_BOTOCORE_LOGS=True /home/zuul/venv/bin/python && sleep 0'
The full traceback is:
Traceback (most recent call last):
  File "<stdin>", line 121, in <module>
  File "<stdin>", line 113, in _ansiballz_main
  File "<stdin>", line 61, in invoke_module
  File "/usr/lib64/python3.8/runpy.py", line 207, in run_module
    return _run_module_code(code, init_globals, run_name, mod_spec)
  File "/usr/lib64/python3.8/runpy.py", line 97, in _run_module_code
    _run_code(code, mod_globals, init_globals,
  File "/usr/lib64/python3.8/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/tmp/ansible_ec2_instance_payload_ofa2yzhm/ansible_ec2_instance_payload.zip/ansible_collections/amazon/aws/plugins/modules/ec2_instance.py", line 2105, in <module>
  File "/tmp/ansible_ec2_instance_payload_ofa2yzhm/ansible_ec2_instance_payload.zip/ansible_collections/amazon/aws/plugins/modules/ec2_instance.py", line 2097, in main
  File "/tmp/ansible_ec2_instance_payload_ofa2yzhm/ansible_ec2_instance_payload.zip/ansible_collections/amazon/aws/plugins/modules/ec2_instance.py", line 1783, in handle_existing
TypeError: 'NoneType' object is not iterable
fatal: [testhost]: FAILED! => {
    "changed": false,
    "module_stderr": "Traceback (most recent call last):\n  File \"<stdin>\", line 121, in <module>\n  File \"<stdin>\", line 113, in _ansiballz_main\n  File \"<stdin>\", line 61, in invoke_module\n  File \"/usr/lib64/python3.8/runpy.py\", line 207, in run_module\n    return _run_module_code(code, init_globals, run_name, mod_spec)\n  File \"/usr/lib64/python3.8/runpy.py\", line 97, in _run_module_code\n    _run_code(code, mod_globals, init_globals,\n  File \"/usr/lib64/python3.8/runpy.py\", line 87, in _run_code\n    exec(code, run_globals)\n  File \"/tmp/ansible_ec2_instance_payload_ofa2yzhm/ansible_ec2_instance_payload.zip/ansible_collections/amazon/aws/plugins/modules/ec2_instance.py\", line 2105, in <module>\n  File \"/tmp/ansible_ec2_instance_payload_ofa2yzhm/ansible_ec2_instance_payload.zip/ansible_collections/amazon/aws/plugins/modules/ec2_instance.py\", line 2097, in main\n  File \"/tmp/ansible_ec2_instance_payload_ofa2yzhm/ansible_ec2_instance_payload.zip/ansible_collections/amazon/aws/plugins/modules/ec2_instance.py\", line 1783, in handle_existing\nTypeError: 'NoneType' object is not iterable\n",
    "module_stdout": "",
    "msg": "MODULE FAILURE\nSee stdout/stderr for the exact error",
    "rc": 1
}

Reviewed-by: Mark Chappell <None>
Reviewed-by: Joseph Torcasso <None>

plugins/modules/ec2_instance.py

@@ -1780,15 +1780,15 @@ def determine_iam_role(name_or_arn):
 
 
 def handle_existing(existing_matches, state):
-    tags = dict(module.params.get('tags', None))
+    tags = module.params.get('tags')
     purge_tags = module.params.get('purge_tags')
     name = module.params.get('name')
 
     # Name is a tag rather than a direct parameter, we need to inject 'Name'
     # into tags, but since tags isn't explicitly passed we'll treat it not being
     # set as purge_tags == False
     if name:
-        if purge_tags and tags is None:
+        if tags is None:
             purge_tags = False
             tags = {}
         tags.update({'Name': name})

tests/integration/targets/ec2_instance/roles/ec2_instance/tasks/tags_and_vpc_settings.yml

@@ -138,11 +138,45 @@
         - check_tags.instances[0].tags.Name.startswith(resource_prefix)
         - "'{{ check_tags.instances[0].state.name }}' in  ['pending', 'running']"
 
+  - name: "Try setting purge_tags to True without specifiying tags (should NOT purge tags)"
+    ec2_instance:
+      state: present
+      name: "{{ resource_prefix }}-test-basic-vpc-create"
+      image_id: "{{ ec2_ami_id }}"
+      purge_tags: true
+      security_groups: "{{ sg.group_id }}"
+      vpc_subnet_id: "{{ testing_subnet_b.subnet.id }}"
+      instance_type: "{{ ec2_instance_type }}"
+    register: _purge_tags_without_tags
+
+  - name: Assert tags were not purged
+    assert:
+      that:
+        - _purge_tags_without_tags.instances[0].tags | length > 1
+
+  - name: "Purge all tags (aside from Name)"
+    ec2_instance:
+      state: present
+      name: "{{ resource_prefix }}-test-basic-vpc-create"
+      image_id: "{{ ec2_ami_id }}"
+      purge_tags: true
+      tags: {}
+      security_groups: "{{ sg.group_id }}"
+      vpc_subnet_id: "{{ testing_subnet_b.subnet.id }}"
+      instance_type: "{{ ec2_instance_type }}"
+    register: _purge_tags
+
+  - name: Assert tags were purged
+    assert:
+      that:
+        - _purge_tags.instances[0].tags | length == 1
+        - _purge_tags.instances[0].tags.Name.startswith(resource_prefix)
+
   - name: "Terminate instance"
     ec2_instance:
       state: absent
       filters:
-        "tag:TestId": "{{ ec2_instance_tag_TestId }}"
+        "tag:Name": "{{ resource_prefix }}-test-basic-vpc-create"
       wait: false
     register: result
   - assert: