From 9619414fc34a455691c2297b6a67b83336a5947c Mon Sep 17 00:00:00 2001
From: Jonathan Sokolowski <jonathan.sokolowski@gmail.com>
Date: Wed, 17 Mar 2021 14:38:26 +1100
Subject: [PATCH] Add ec2_asg_tag module

A new module to manage ASG tags, analogous to the `ec2_tag` module in
`amazon.aws` collection.

Fixes #481
---
 plugins/modules/ec2_asg_tag.py                | 228 ++++++++++++++++++
 .../targets/ec2_asg/tasks/main.yml            |  86 +++++++
 .../unit/plugins/modules/test_ec2_asg_tag.py  | 115 +++++++++
 3 files changed, 429 insertions(+)
 create mode 100644 plugins/modules/ec2_asg_tag.py
 create mode 100644 tests/unit/plugins/modules/test_ec2_asg_tag.py

diff --git a/plugins/modules/ec2_asg_tag.py b/plugins/modules/ec2_asg_tag.py
new file mode 100644
index 00000000000..fb767e08a7c
--- /dev/null
+++ b/plugins/modules/ec2_asg_tag.py
@@ -0,0 +1,228 @@
+#!/usr/bin/python
+# This file is part of Ansible
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import absolute_import, division, print_function
+
+__metaclass__ = type
+
+
+DOCUMENTATION = r'''
+---
+module: ec2_asg_tag
+version_added: 1.5.0
+short_description: Create and remove tags on AWS AutoScaling Groups (ASGs)
+description:
+  - Creates, modifies and removes tags for AutoScaling Groups
+author: "Jonathan Sokolowski (@jsok)"
+requirements: [ "boto3", "botocore" ]
+options:
+  name:
+    description:
+      - The ASG name.
+    required: true
+    type: str
+  state:
+    description:
+      - Whether the tags should be present or absent on the ASG.
+    default: present
+    choices: ['present', 'absent']
+    type: str
+  tags:
+    description:
+      - A list of tags to add or remove from the ASG.
+      - If the value provided for a key is not set and I(state=absent), the tag will be removed regardless of its current value.
+      - Optional key is I(propagate_at_launch), which defaults to true.
+    type: list
+    elements: dict
+  purge_tags:
+    description:
+      - Whether unspecified tags should be removed from the resource.
+      - Note that when combined with I(state=absent), specified tags with non-matching values are not purged.
+    type: bool
+    default: false
+extends_documentation_fragment:
+- amazon.aws.aws
+- amazon.aws.ec2
+'''
+
+EXAMPLES = r'''
+- name: Ensure tags are present on an ASG
+  community.aws.ec2_asg_tag:
+    name: my-auto-scaling-group
+    state: present
+    tags:
+      - environment: production
+        propagate_at_launch: true
+      - role: webserver
+        propagate_at_launch: true
+
+- name: Ensure tag is absent on an ASG
+  community.aws.ec2_asg_tag:
+    name: my-auto-scaling-group
+    state: absent
+    tags:
+      - environment: development
+'''
+
+RETURN = r'''
+---
+tags:
+  description: A list containing the tags on the resource
+  returned: always
+  type: list
+  sample: [
+      {
+          "key": "Name",
+          "value": "public-webapp-production-1",
+          "resource_id": "public-webapp-production-1",
+          "resource_type": "auto-scaling-group",
+          "propagate_at_launch": "true"
+      },
+      {
+          "key": "env",
+          "value": "production",
+          "resource_id": "public-webapp-production-1",
+          "resource_type": "auto-scaling-group",
+          "propagate_at_launch": "true"
+      }
+  ]
+added_tags:
+  description: A list of tags that were added to the ASG
+  returned: If tags were added
+  type: list
+removed_tags:
+  description: A list of tags that were removed from the ASG
+  returned: If tags were removed
+  type: list
+'''
+
+try:
+    from botocore.exceptions import BotoCoreError, ClientError
+except ImportError:
+    pass  # Handled by AnsibleAWSModule
+
+from ansible.module_utils._text import to_native
+
+from ansible_collections.amazon.aws.plugins.module_utils.core import AnsibleAWSModule
+from ansible_collections.amazon.aws.plugins.module_utils.ec2 import AWSRetry
+
+backoff_params = dict(tries=10, delay=3, backoff=1.5)
+
+
+def to_boto3_tag_list(tags, group_name):
+    tag_list = []
+    for tag in tags:
+        for k, v in tag.items():
+            if k == 'propagate_at_launch':
+                continue
+            tag_list.append(dict(Key=k,
+                                 Value=to_native(v) if v else v,
+                                 PropagateAtLaunch=bool(tag.get('propagate_at_launch', True)),
+                                 ResourceType='auto-scaling-group',
+                                 ResourceId=group_name))
+    return tag_list
+
+
+def compare_asg_tags(current_tags_dict, new_tags_dict, purge_tags=True):
+    """
+    Compare two ASG tag dicts.
+
+    :param current_tags_dict: dict of currently defined boto3 tags.
+    :param new_tags_dict: dict of new boto3 tags to apply.
+    :param purge_tags: whether to consider tags not in new_tags_dict for removal.
+    :return: tags_to_set: a dict of boto3 tags to set. If all tags are identical this list will be empty.
+    :return: tags_keys_to_unset: a list of tag keys to be unset. If no tags need to be unset this list will be empty.
+    """
+
+    tags_to_set = {}
+    tag_keys_to_unset = []
+
+    for key in current_tags_dict.keys():
+        if key not in new_tags_dict and purge_tags:
+            tag_keys_to_unset.append(key)
+
+    for key in set(new_tags_dict.keys()) - set(tag_keys_to_unset):
+        if new_tags_dict[key] != current_tags_dict.get(key):
+            tags_to_set[key] = new_tags_dict[key]
+
+    return tags_to_set, tag_keys_to_unset
+
+
+def tag_list_to_dict(tag_list):
+    return {tag['Key']: tag for tag in tag_list}
+
+
+def get_tags(autoscaling, module, group_name):
+    filters = [{'Name': 'auto-scaling-group', 'Values': [group_name]}]
+    try:
+        result = AWSRetry.jittered_backoff()(autoscaling.describe_tags)(Filters=filters)
+        return result['Tags']
+    except (BotoCoreError, ClientError) as e:
+        module.fail_json_aws(e, msg='Failed to fetch tags for ASG {0}'.format(group_name))
+
+
+def main():
+    argument_spec = dict(
+        name=dict(required=True, type='str'),
+        tags=dict(type='list', default=[], elements='dict'),
+        purge_tags=dict(type='bool', default=False),
+        state=dict(default='present', choices=['present', 'absent']),
+    )
+
+    module = AnsibleAWSModule(argument_spec=argument_spec, supports_check_mode=True)
+
+    group_name = module.params['name']
+    state = module.params['state']
+    tags = module.params['tags']
+    purge_tags = module.params['purge_tags']
+
+    result = {'changed': False}
+
+    autoscaling = module.client('autoscaling')
+    current_tag_list = get_tags(autoscaling, module, group_name)
+    new_tag_list = to_boto3_tag_list(tags, group_name)
+
+    # convert to a dict keyed by the tag Key to simplify existence checks
+    current_tags = tag_list_to_dict(current_tag_list)
+    new_tags = tag_list_to_dict(new_tag_list)
+
+    add_tags, remove_keys = compare_asg_tags(current_tags, new_tags, purge_tags=purge_tags)
+
+    remove_tags = {}
+    if state == 'absent':
+        for key in new_tags:
+            tag_value = new_tags[key].get('Value')
+            if key in current_tags:
+                if tag_value is None or current_tags[key] == new_tags[key]:
+                    remove_tags[key] = current_tags[key]
+
+    for key in remove_keys:
+        remove_tags[key] = current_tags[key]
+
+    if remove_tags:
+        remove_tag_list = remove_tags.items()
+        result['changed'] = True
+        result['removed_tags'] = remove_tag_list
+        if not module.check_mode:
+            try:
+                AWSRetry.jittered_backoff()(autoscaling.delete_tags)(Tags=remove_tag_list)
+            except (BotoCoreError, ClientError) as e:
+                module.fail_json_aws(e, msg='Failed to remove tags {0} from ASG {1}'.format(remove_tag_list, group_name))
+
+    if state == 'present' and add_tags:
+        add_tag_list = add_tags.items()
+        result['changed'] = True
+        result['added_tags'] = add_tag_list
+        if not module.check_mode:
+            try:
+                AWSRetry.jittered_backoff()(autoscaling.create_or_update_tags)(Tags=add_tag_list)
+            except (BotoCoreError, ClientError) as e:
+                module.fail_json_aws(e, msg='Failed to add tags {0} from ASG {1}'.format(add_tag_list, group_name))
+
+    result['tags'] = get_tags(autoscaling, module, group_name)
+    module.exit_json(**result)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/tests/integration/targets/ec2_asg/tasks/main.yml b/tests/integration/targets/ec2_asg/tasks/main.yml
index aa53e9688ea..0ad2dc6185a 100644
--- a/tests/integration/targets/ec2_asg/tasks/main.yml
+++ b/tests/integration/targets/ec2_asg/tasks/main.yml
@@ -247,6 +247,92 @@
           - "output.tags | length == 1"
           - output is changed
 
+    # ============================================================
+
+    - name: Add some tags to the asg
+      ec2_asg_tag:
+        name: "{{ resource_prefix }}-asg"
+        state: present
+        tags:
+        - tag_d: 'value 4'
+          propagate_at_launch: no
+        - tag_e: 'value 5'
+          propagate_at_launch: yes
+      register: output
+
+    - assert:
+        that:
+          - "output.added_tags | length == 2"
+          - output is changed
+
+    - name: Update propagate_at_launch on existing tag
+      ec2_asg_tag:
+        name: "{{ resource_prefix }}-asg"
+        state: present
+        tags:
+        - tag_d: 'value 4'
+          propagate_at_launch: yes
+      register: output
+
+    - assert:
+        that:
+          - "output.added_tags | length == 1"
+          - output is changed
+
+    - name: Add an existing tag to the asg
+      ec2_asg_tag:
+        name: "{{ resource_prefix }}-asg"
+        state: present
+        tags:
+        - tag_d: 'value 4'
+          propagate_at_launch: yes
+      register: output
+
+    - assert:
+        that:
+          - output is not changed
+
+    - name: Remove a tag from the asg
+      ec2_asg_tag:
+        name: "{{ resource_prefix }}-asg"
+        state: absent
+        tags:
+        - tag_d: 'value 4'
+      register: output
+
+    - assert:
+        that:
+          - "output.removed_tags | length == 1"
+          - output is changed
+
+    - name: Remove a tag (without specifying the value) from the asg
+      ec2_asg_tag:
+        name: "{{ resource_prefix }}-asg"
+        state: absent
+        tags:
+        - tag_e:
+      register: output
+
+    - assert:
+        that:
+          - "output.removed_tags | length == 1"
+          - output is changed
+
+    - name: Remove a non-existent tag from the asg
+      ec2_asg_tag:
+        name: "{{ resource_prefix }}-asg"
+        state: absent
+        tags:
+        - tag_e:
+          propagate_at_launch: yes
+      register: output
+
+    - assert:
+        that:
+          - output is not changed
+
+    # ============================================================
+
     - name: Enable metrics collection
       ec2_asg:
         name: "{{ resource_prefix }}-asg"
diff --git a/tests/unit/plugins/modules/test_ec2_asg_tag.py b/tests/unit/plugins/modules/test_ec2_asg_tag.py
new file mode 100644
index 00000000000..e34eb70bafe
--- /dev/null
+++ b/tests/unit/plugins/modules/test_ec2_asg_tag.py
@@ -0,0 +1,115 @@
+# (c) 2021 Red Hat Inc.
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import pytest
+
+from ansible_collections.community.aws.plugins.modules.ec2_asg_tag import (
+    compare_asg_tags,
+    tag_list_to_dict,
+    to_boto3_tag_list,
+)
+
+
+def as_tags(tags):
+    return tag_list_to_dict(to_boto3_tag_list(tags, 'asg-test'))
+
+
+def test_compare_asg_tags__add_tag():
+    current_tags = as_tags([
+        {'env': 'production', 'propagate_at_launch': True},
+    ])
+    new_tags = as_tags([
+        {'role': 'web', 'propagate_at_launch': True},
+    ])
+
+    add, remove = compare_asg_tags(current_tags, new_tags, purge_tags=True)
+    assert len(add) == 1
+    assert 'role' in add
+    assert len(remove) == 1
+    assert 'env' in remove
+
+    add, remove = compare_asg_tags(current_tags, new_tags, purge_tags=False)
+    assert len(add) == 1
+    assert 'role' in add
+    assert len(remove) == 0
+
+
+def test_compare_asg_tags__existing_tag():
+    current_tags = as_tags([
+        {'env': 'production', 'propagate_at_launch': True},
+        {'role': 'web', 'propagate_at_launch': True},
+    ])
+    new_tags = as_tags([
+        {'role': 'web', 'propagate_at_launch': True},
+    ])
+
+    add, remove = compare_asg_tags(current_tags, new_tags, purge_tags=True)
+    assert len(add) == 0
+    assert len(remove) == 1
+    assert 'env' in remove
+
+    add, remove = compare_asg_tags(current_tags, new_tags, purge_tags=False)
+    assert len(add) == 0
+    assert len(remove) == 0
+
+
+def test_compare_asg_tags__remove_tag():
+    current_tags = as_tags([
+        {'env': 'production', 'propagate_at_launch': True},
+        {'role': 'web', 'propagate_at_launch': True},
+    ])
+    new_tags = as_tags([])
+
+    add, remove = compare_asg_tags(current_tags, new_tags, purge_tags=True)
+    assert len(add) == 0
+    assert len(remove) == 2
+    assert 'role' in remove
+
+    add, remove = compare_asg_tags(current_tags, new_tags, purge_tags=False)
+    assert len(add) == 0
+    assert len(remove) == 0
+
+
+def test_compare_asg_tags__empty_value():
+    current_tags = as_tags([
+        {'env': 'production', 'propagate_at_launch': True},
+        {'role': 'web', 'propagate_at_launch': True},
+    ])
+    new_tags = as_tags([
+        {'role': None},
+    ])
+
+    add, remove = compare_asg_tags(current_tags, new_tags, purge_tags=True)
+    assert len(add) == 1
+    assert 'role' in add
+    assert len(remove) == 1
+    assert 'env' in remove
+
+    add, remove = compare_asg_tags(current_tags, new_tags, purge_tags=False)
+    assert len(add) == 1
+    assert 'role' in add
+    assert len(remove) == 0
+
+
+def test_compare_asg_tags__update_propagate():
+    current_tags = as_tags([
+        {'env': 'production', 'propagate_at_launch': True},
+        {'role': 'web', 'propagate_at_launch': False},
+    ])
+    new_tags = as_tags([
+        {'role': 'web', 'propagate_at_launch': True},
+    ])
+
+    add, remove = compare_asg_tags(current_tags, new_tags, purge_tags=True)
+    assert len(add) == 1
+    assert 'role' in add
+    assert len(remove) == 1
+    assert 'env' in remove
+
+    add, remove = compare_asg_tags(current_tags, new_tags, purge_tags=False)
+    assert len(add) == 1
+    assert 'role' in add
+    assert len(remove) == 0