aws2_ec2 inventory: populate ec2_tag_* hostvars

This patch exposes a new `use_contrib_script_compatible_ec2_tag_keys`
that can be used to reproduce a behior of the old `ec2.py` inventory
script from contrib.

Closes: ansible-collections#183

changelogs/fragments/331_aws_ec2_inventory_use_contrib_script_compatible_ec2_tag_keys.yaml

@@ -0,0 +1,3 @@
+---
+minor_changes:
+- "aws_ec2 inventory - expose a new configuration key ``use_contrib_script_compatible_ec2_tag_keys`` to reproduce a behavior of the old ``ec2.py`` inventory script. With this option enabled, each tag is exposed using a ``ec2_tag_TAGNAME`` key (https://github.com/ansible-collections/amazon.aws/pull/331)."

plugins/inventory/aws_ec2.py

@@ -76,6 +76,12 @@
               which group names end up being used as.
           type: bool
           default: False
+        use_contrib_script_compatible_ec2_tag_keys:
+          description:
+            - Expose the host tags with ec2_tag_TAGNAME keys like the old ec2.py inventory script.
+            - The use of this feature is discouraged and we advise to migrate to the new ``tags`` structure.
+          type: bool
+          default: False
 '''
 
 EXAMPLES = '''
@@ -564,6 +570,10 @@ def _add_hosts(self, hosts, group, hostnames):
             host = camel_dict_to_snake_dict(host, ignore_list=['Tags'])
             host['tags'] = boto3_tag_list_to_ansible_dict(host.get('tags', []))
 
+            if self.get_option('use_contrib_script_compatible_ec2_tag_keys'):
+                for k, v in host['tags'].items():
+                    host["ec2_tag_%s" % k] = v
+
             # Allow easier grouping by region
             host['placement']['region'] = host['placement']['availability_zone'][:-1]
 

tests/integration/targets/inventory_aws_ec2/playbooks/test_populating_inventory_with_use_contrib_script_keys.yml

@@ -0,0 +1,62 @@
+---
+- hosts: 127.0.0.1
+  connection: local
+  gather_facts: no
+  environment: "{{ ansible_test.environment }}"
+  tasks:
+
+    - module_defaults:
+        group/aws:
+          aws_access_key: '{{ aws_access_key }}'
+          aws_secret_key: '{{ aws_secret_key }}'
+          security_token: '{{ security_token | default(omit) }}'
+          region: '{{ aws_region }}'
+      block:
+
+        # Create VPC, subnet, security group, and find image_id to create instance
+        - include_tasks: setup.yml
+
+        # Create new host, refresh inventory
+        - name: create a new host
+          ec2:
+            image: '{{ image_id }}'
+            exact_count: 1
+            count_tag:
+              Name: '{{ resource_prefix }}:/aa'
+            instance_tags:
+              Name: '{{ resource_prefix }}:/aa'
+              OtherTag: value
+            instance_type: t2.micro
+            wait: yes
+            group_id: '{{ sg_id }}'
+            vpc_subnet_id: '{{ subnet_id }}'
+          register: setup_instance
+
+        - meta: refresh_inventory
+
+        - name: "register the current hostname, the : and / a replaced with _"
+          set_fact:
+            expected_hostname: "{{ resource_prefix }}__aa"
+
+        - name: "Ensure we've got a hostvars entry for the new host"
+          assert:
+            that:
+              - expected_hostname in hostvars
+              - hostvars[expected_hostname].ec2_tag_OtherTag == "value"
+
+      always:
+
+        - name: remove setup ec2 instance
+          ec2:
+            instance_type: t2.micro
+            instance_ids: '{{ setup_instance.instance_ids }}'
+            state: absent
+            wait: yes
+            instance_tags:
+              Name: '{{ resource_prefix }}'
+            group_id: "{{ sg_id }}"
+            vpc_subnet_id: "{{ subnet_id }}"
+          ignore_errors: yes
+          when: setup_instance is defined
+
+        - include_tasks: tear_down.yml

tests/integration/targets/inventory_aws_ec2/runme.sh

@@ -39,5 +39,9 @@ ansible-playbook playbooks/test_populating_inventory_with_constructed.yml "$@"
 ansible-playbook playbooks/create_inventory_config.yml -e "template='inventory_with_concatenation.yml.j2'" "$@"
 ansible-playbook playbooks/test_populating_inventory_with_concatenation.yml "$@"
 
+# generate inventory config with caching and test using it
+ansible-playbook playbooks/create_inventory_config.yml -e "template='inventory_with_use_contrib_script_keys.yml.j2'" "$@"
+ANSIBLE_TRANSFORM_INVALID_GROUP_CHARS=never ansible-playbook playbooks/test_populating_inventory_with_use_contrib_script_keys.yml "$@"
+
 # cleanup inventory config
 ansible-playbook playbooks/empty_inventory_config.yml "$@"

tests/integration/targets/inventory_aws_ec2/templates/inventory_with_use_contrib_script_keys.yml.j2

@@ -0,0 +1,15 @@
+plugin: amazon.aws.aws_ec2
+aws_access_key_id: '{{ aws_access_key }}'
+aws_secret_access_key: '{{ aws_secret_key }}'
+{% if security_token | default(false) %}
+aws_security_token: '{{ security_token }}'
+{% endif %}
+regions:
+- '{{ aws_region }}'
+filters:
+  tag:Name:
+  - '{{ resource_prefix }}:/aa'
+hostnames:
+- tag:Name
+use_contrib_script_compatible_sanitization: True
+use_contrib_script_compatible_ec2_tag_keys: True