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/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',