inventory aws_ec2 - allow for literal strings in hostnames (ansible-c…

…ollections#826) (ansible-collections#836)

[PR ansible-collections#826/944bb1fe backport][stable-3] inventory aws_ec2 - allow for literal strings in hostnames

This is a backport of PR ansible-collections#826 as merged into main (944bb1f).
SUMMARY
Allow for literal strings in hostnames rather than throwing an AnsibleError
Fixes ansible-collections#814
ISSUE TYPE

Feature Pull Request

COMPONENT NAME
aws_ec2
ADDITIONAL INFORMATION
Is there a better way of allowing for literal strings here?

Reviewed-by: Joseph Torcasso <None>
Reviewed-by: Jill R <None>

changelogs/fragments/826-inventory-aws_ec2-allow-literal-string-in-hostname.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - aws_ec2 inventory - Allow for literal strings in hostname that don't match filter parameters in ec2 describe-instances (https://github.com/ansible-collections/amazon.aws/pull/826).

plugins/inventory/aws_ec2.py

@@ -39,11 +39,31 @@
         hostnames:
           description:
               - A list in order of precedence for hostname variables.
-              - You can use the options specified in U(http://docs.aws.amazon.com/cli/latest/reference/ec2/describe-instances.html#options).
-              - To use tags as hostnames use the syntax tag:Name=Value to use the hostname Name_Value, or tag:Name to use the value of the Name tag.
           type: list
           elements: dict
           default: []
+          suboptions:
+            name:
+                description:
+                    - Name of the host.
+                    - Can be one of the options specified in U(http://docs.aws.amazon.com/cli/latest/reference/ec2/describe-instances.html#options).
+                    - To use tags as hostnames use the syntax tag:Name=Value to use the hostname Name_Value, or tag:Name to use the value of the Name tag.
+                    - If value provided does not exist in the above options, it will be used as a literal string.
+                type: str
+                required: True
+            prefix:
+                description:
+                    - Prefix to prepend to I(name). Same options as I(name).
+                    - If I(prefix) is specified, final hostname will be I(prefix) +  I(separator) + I(name).
+                type: str
+                default: ''
+                required: False
+            separator:
+                description:
+                    - Value to separate I(prefix) and I(name) when I(prefix) is specified.
+                type: str
+                default: '_'
+                required: False
         filters:
           description:
               - A dictionary of filter value pairs.
@@ -149,6 +169,9 @@
   - name: 'private-ip-address'
     separator: '_'
     prefix: 'tag:Name'
+  - name: 'test_literal' # Using literal values for hostname
+    separator: '-'       # Hostname will be aws-test_literal
+    prefix: 'aws'
 
 # Example using constructed features to create groups and set ansible_host
 plugin: aws_ec2
@@ -387,9 +410,11 @@ def _get_boto_attr_chain(self, filter_name, instance):
             :param instance: instance dict returned by boto3 ec2 describe_instances()
         '''
         allowed_filters = sorted(list(instance_data_filter_to_boto_attr.keys()) + list(instance_meta_filter_to_boto_attr.keys()))
+
+        # If filter not in allow_filters -> use it as a literal string
         if filter_name not in allowed_filters:
-            raise AnsibleError("Invalid filter '%s' provided; filter must be one of %s." % (filter_name,
-                                                                                            allowed_filters))
+            return filter_name
+
         if filter_name in instance_data_filter_to_boto_attr:
             boto_attr_list = instance_data_filter_to_boto_attr[filter_name]
         else:

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

@@ -0,0 +1,56 @@
+---
+- 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_instance:
+            image_id: '{{ image_id }}'
+            name: '{{ resource_prefix }}'
+            tags:
+              OtherTag: value
+            instance_type: t2.micro
+            security_groups: '{{ sg_id }}'
+            vpc_subnet_id: '{{ subnet_id }}'
+            wait: no
+          register: setup_instance
+
+        - meta: refresh_inventory
+
+        - name: register the current hostname
+          set_fact:
+            expected_hostname: "aws-{{ resource_prefix }}"
+
+        - name: "Ensure we've got a hostvars entry for the new host"
+          assert:
+            that:
+              - expected_hostname in hostvars
+
+      always:
+
+        - name: remove setup ec2 instance
+          ec2_instance:
+            instance_type: t2.micro
+            instance_ids: '{{ setup_instance.instance_ids }}'
+            state: absent
+            name: '{{ resource_prefix }}'
+            security_groups: "{{ 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

@@ -38,6 +38,9 @@ ansible-playbook playbooks/create_inventory_config.yml -e "template='inventory_w
 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 "$@"
+ansible-playbook playbooks/create_inventory_config.yml -e "template='inventory_with_literal_string.yml.j2'" "$@"
+ansible-playbook playbooks/test_populating_inventory_with_literal_string.yml "$@"
+
 # generate inventory config with includes_entries_matching and prepare the tests
 ansible-playbook playbooks/create_inventory_config.yml -e "template='inventory_with_include_or_exclude_filters.yml.j2'" "$@"
 ansible-playbook playbooks/test_populating_inventory_with_include_or_exclude_filters.yml "$@"

tests/integration/targets/inventory_aws_ec2/templates/inventory_with_literal_string.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 }}'
+hostnames:
+  - name: 'tag:Name'
+    separator: '-'
+    prefix: 'aws'