Add docker_context_info module (#1039)

* Vendor parts of the Docker SDK for Python

This is a combination of the latest git version
(https://github.com/docker/docker-py/tree/db7f8b8bb67e485a7192846906f600a52e0aa623)
with some fixes to make it compatible with Python 2.7
and adjusting some imports.

* Polishing.

* Fix bug that prevents contexts to be found when no Docker config file is present.

Ref: https://github.com/docker/docker-py/issues/3190

* Linting.

* Fix typos.

* Adjust more to behavior of Docker CLI.

* Add first iteration of docker_context_info module.

* Improvements.

* Add basic CI.

* Add caveat on contexts[].config result.

tests/integration/targets/docker_context_info/aliases

@@ -0,0 +1,6 @@
+# Copyright (c) Ansible Project
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+azp/5
+destructive

tests/integration/targets/docker_context_info/meta/main.yml

@@ -0,0 +1,8 @@
+---
+# Copyright (c) Ansible Project
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+dependencies:
+  - setup_docker
+  - setup_docker_python_deps

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

@@ -0,0 +1,40 @@
+---
+# Copyright (c) Ansible Project
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+####################################################################
+# WARNING: These are designed specifically for Ansible tests       #
+# and should not be used as examples of how to write Ansible roles #
+####################################################################
+
+# Create random name prefix (for containers, networks, ...)
+- name: Create random container name prefix
+  set_fact:
+    cname_prefix: "{{ 'ansible-docker-test-%0x' % ((2**32) | random) }}"
+    cnames: []
+
+- debug:
+    msg: "Using container name prefix {{ cname_prefix }}"
+
+# Run the tests
+- block:
+    - include_tasks: run-test.yml
+      with_fileglob:
+        - "tests/*.yml"
+      loop_control:
+        loop_var: test_name
+
+  always:
+    - name: "Make sure all containers are removed"
+      docker_container:
+        name: "{{ item }}"
+        state: absent
+        force_kill: true
+      with_items: "{{ cnames }}"
+      diff: false
+
+  when: docker_api_version is version('1.25', '>=')
+
+- fail: msg="Too old docker / docker-py version to run all docker_container tests!"
+  when: not(docker_api_version is version('1.25', '>=')) and (ansible_distribution != 'CentOS' or ansible_distribution_major_version|int > 6)

tests/integration/targets/docker_context_info/tasks/run-test.yml

@@ -0,0 +1,7 @@
+---
+# Copyright (c) Ansible Project
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+- name: "Loading tasks from {{ test_name }}"
+  include_tasks: "{{ test_name }}"

tests/integration/targets/docker_context_info/tasks/tests/default-context.yml

@@ -0,0 +1,121 @@
+---
+# Copyright (c) Ansible Project
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+- name: Registering container name
+  set_fact:
+    cname: "{{ cname_prefix ~ '-hi' }}"
+- name: Registering container name
+  set_fact:
+    cnames: "{{ cnames + [cname] }}"
+
+- name: Get current context
+  community.docker.docker_context_info:
+    only_current: true
+  register: docker_current_context
+
+- assert:
+    that:
+      - docker_current_context is not changed
+      # Some of the following tests will not be true on all machines, but they should be in CI:
+      - docker_current_context.current_context_name == 'default'
+      - docker_current_context.contexts | length == 1
+      - docker_current_context.contexts[0].name == 'default'
+      - docker_current_context.contexts[0].current == true
+      - docker_current_context.contexts[0].description == 'Current DOCKER_HOST based configuration'
+      - docker_current_context.contexts[0].meta_path is none
+      - docker_current_context.contexts[0].tls_path is none
+      - docker_current_context.contexts[0].config.docker_host == 'unix:///var/run/docker.sock'
+      - docker_current_context.contexts[0].config.tls == false
+
+- name: Run community.docker modules with current context
+  module_defaults:
+    group/community.docker.docker: "{{ docker_current_context.contexts[0].config }}"
+  block:
+    - name: Create container
+      docker_container:
+        image: "{{ docker_test_image_alpine }}"
+        command: '/bin/sh -c "sleep 10m"'
+        name: "{{ cname }}"
+        state: present
+      register: create_1
+
+    - name: Create container (idempotent)
+      docker_container:
+        image: "{{ docker_test_image_alpine }}"
+        command: '/bin/sh -c "sleep 10m"'
+        name: "{{ cname }}"
+        state: present
+      register: create_2
+
+    - assert:
+        that:
+        - create_1 is changed
+        - create_2 is not changed
+
+    - name: Inspect container with CLI tool
+      ansible.builtin.command:
+        cmd: docker inspect {{ cname }}
+      register: result
+
+    - assert:
+        that:
+          - (result.stdout | from_json) | length == 1
+          - (result.stdout | from_json)[0].State.Status == "created"
+
+    - name: Start container
+      docker_container:
+        name: "{{ cname }}"
+        state: started
+      register: start_1
+
+    - name: Start container (idempotent)
+      docker_container:
+        name: "{{ cname }}"
+        state: started
+      register: start_2
+
+    - assert:
+        that:
+        - start_1 is changed
+        - start_2 is not changed
+
+    - name: Inspect container with CLI tool
+      ansible.builtin.command:
+        cmd: docker inspect {{ cname }}
+      register: result
+
+    - assert:
+        that:
+          - (result.stdout | from_json) | length == 1
+          - (result.stdout | from_json)[0].State.Status == "running"
+
+    - name: Remove container
+      docker_container:
+        name: "{{ cname }}"
+        state: absent
+        force_kill: true
+      register: remove_1
+
+    - name: Remove container (idempotent)
+      docker_container:
+        name: "{{ cname }}"
+        state: absent
+        force_kill: true
+      register: remove_2
+
+    - assert:
+        that:
+        - remove_1 is changed
+        - remove_2 is not changed
+
+    - name: Inspect container with CLI tool
+      ansible.builtin.command:
+        cmd: docker inspect {{ cname }}
+      register: result
+      failed_when: result.rc != 1
+
+    - assert:
+        that:
+          - (result.stdout | from_json) | length == 0

tests/sanity/extra/action-group.py

@@ -20,6 +20,7 @@ ACTION_GROUPS = {
         'pattern': re.compile('^.*$'),
         'exclusions': [
             'current_container_facts',
+            'docker_context_info',
         ],
         'doc_fragment': 'community.docker.attributes.actiongroup_docker',
     },

tests/unit/plugins/module_utils/_api/test_context.py

@@ -0,0 +1,68 @@
+# -*- coding: utf-8 -*-
+# This code is part of the Ansible collection community.docker, but is an independent component.
+# This particular file, and this file only, is based on the Docker SDK for Python (https://github.com/docker/docker-py/)
+#
+# Copyright (c) 2016-2025 Docker, Inc.
+#
+# It is licensed under the Apache 2.0 license (see LICENSES/Apache-2.0.txt in this collection)
+# SPDX-License-Identifier: Apache-2.0
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import unittest
+
+import pytest
+
+from ansible_collections.community.docker.plugins.module_utils._api import errors
+from ansible_collections.community.docker.plugins.module_utils._api.constants import (
+    DEFAULT_NPIPE,
+    DEFAULT_UNIX_SOCKET,
+    IS_WINDOWS_PLATFORM,
+)
+from ansible_collections.community.docker.plugins.module_utils._api.context.api import ContextAPI
+from ansible_collections.community.docker.plugins.module_utils._api.context.context import Context
+
+
+class BaseContextTest(unittest.TestCase):
+    @pytest.mark.skipif(
+        IS_WINDOWS_PLATFORM, reason='Linux specific path check'
+    )
+    def test_url_compatibility_on_linux(self):
+        c = Context("test")
+        assert c.Host == DEFAULT_UNIX_SOCKET[5:]
+
+    @pytest.mark.skipif(
+        not IS_WINDOWS_PLATFORM, reason='Windows specific path check'
+    )
+    def test_url_compatibility_on_windows(self):
+        c = Context("test")
+        assert c.Host == DEFAULT_NPIPE
+
+    def test_fail_on_default_context_create(self):
+        with pytest.raises(errors.ContextException):
+            ContextAPI.create_context("default")
+
+    def test_default_in_context_list(self):
+        found = False
+        ctx = ContextAPI.contexts()
+        for c in ctx:
+            if c.Name == "default":
+                found = True
+        assert found is True
+
+    def test_get_current_context(self):
+        assert ContextAPI.get_current_context().Name == "default"
+
+    def test_https_host(self):
+        c = Context("test", host="tcp://testdomain:8080", tls=True)
+        assert c.Host == "https://testdomain:8080"
+
+    def test_context_inspect_without_params(self):
+        ctx = ContextAPI.inspect_context()
+        assert ctx["Name"] == "default"
+        assert ctx["Metadata"]["StackOrchestrator"] == "swarm"
+        assert ctx["Endpoints"]["docker"]["Host"] in (
+            DEFAULT_NPIPE,
+            DEFAULT_UNIX_SOCKET[5:],
+        )

tests/unit/plugins/module_utils/_api/utils/test_utils.py

@@ -255,7 +255,7 @@ class ParseEnvFileTest(unittest.TestCase):
 class ParseHostTest(unittest.TestCase):
     def test_parse_host(self):
         invalid_hosts = [
-            '0.0.0.0',
+            'foo://0.0.0.0',
             'tcp://',
             'udp://127.0.0.1',
             'udp://127.0.0.1:2375',