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.

plugins/module_utils/_api/context/api.py

@@ -0,0 +1,242 @@
+# -*- 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 json
+import os
+
+from ansible.module_utils.six import raise_from
+
+from .. import errors
+
+from .config import (
+    METAFILE,
+    get_current_context_name,
+    get_meta_dir,
+    write_context_name_to_docker_config,
+)
+from .context import Context
+
+
+def create_default_context():
+    host = None
+    if os.environ.get('DOCKER_HOST'):
+        host = os.environ.get('DOCKER_HOST')
+    return Context("default", "swarm", host, description="Current DOCKER_HOST based configuration")
+
+
+class ContextAPI(object):
+    """Context API.
+    Contains methods for context management:
+    create, list, remove, get, inspect.
+    """
+    DEFAULT_CONTEXT = None
+
+    @classmethod
+    def get_default_context(cls):
+        context = cls.DEFAULT_CONTEXT
+        if context is None:
+            context = create_default_context()
+            cls.DEFAULT_CONTEXT = context
+        return context
+
+    @classmethod
+    def create_context(
+            cls, name, orchestrator=None, host=None, tls_cfg=None,
+            default_namespace=None, skip_tls_verify=False):
+        """Creates a new context.
+        Returns:
+            (Context): a Context object.
+        Raises:
+            :py:class:`docker.errors.MissingContextParameter`
+                If a context name is not provided.
+            :py:class:`docker.errors.ContextAlreadyExists`
+                If a context with the name already exists.
+            :py:class:`docker.errors.ContextException`
+                If name is default.
+
+        Example:
+
+        >>> from docker.context import ContextAPI
+        >>> ctx = ContextAPI.create_context(name='test')
+        >>> print(ctx.Metadata)
+        {
+            "Name": "test",
+            "Metadata": {},
+            "Endpoints": {
+                "docker": {
+                    "Host": "unix:///var/run/docker.sock",
+                    "SkipTLSVerify": false
+                }
+            }
+        }
+        """
+        if not name:
+            raise errors.MissingContextParameter("name")
+        if name == "default":
+            raise errors.ContextException(
+                '"default" is a reserved context name')
+        ctx = Context.load_context(name)
+        if ctx:
+            raise errors.ContextAlreadyExists(name)
+        endpoint = "docker"
+        if orchestrator and orchestrator != "swarm":
+            endpoint = orchestrator
+        ctx = Context(name, orchestrator)
+        ctx.set_endpoint(
+            endpoint, host, tls_cfg,
+            skip_tls_verify=skip_tls_verify,
+            def_namespace=default_namespace)
+        ctx.save()
+        return ctx
+
+    @classmethod
+    def get_context(cls, name=None):
+        """Retrieves a context object.
+        Args:
+            name (str): The name of the context
+
+        Example:
+
+        >>> from docker.context import ContextAPI
+        >>> ctx = ContextAPI.get_context(name='test')
+        >>> print(ctx.Metadata)
+        {
+            "Name": "test",
+            "Metadata": {},
+            "Endpoints": {
+                "docker": {
+                "Host": "unix:///var/run/docker.sock",
+                "SkipTLSVerify": false
+                }
+            }
+        }
+        """
+        if not name:
+            name = get_current_context_name()
+        if name == "default":
+            return cls.get_default_context()
+        return Context.load_context(name)
+
+    @classmethod
+    def contexts(cls):
+        """Context list.
+        Returns:
+            (Context): List of context objects.
+        Raises:
+            :py:class:`docker.errors.APIError`
+                If something goes wrong.
+        """
+        names = []
+        for dirname, dummy, fnames in os.walk(get_meta_dir()):
+            for filename in fnames:
+                if filename == METAFILE:
+                    filepath = os.path.join(dirname, filename)
+                    try:
+                        with open(filepath, "r") as f:
+                            data = json.load(f)
+                        name = data["Name"]
+                        if name == "default":
+                            raise ValueError('"default" is a reserved context name')
+                        names.append(name)
+                    except Exception as e:
+                        raise_from(errors.ContextException(
+                            "Failed to load metafile {filepath}: {e}".format(filepath=filepath, e=e),
+                        ), e)
+
+        contexts = [cls.get_default_context()]
+        for name in names:
+            context = Context.load_context(name)
+            if not context:
+                raise errors.ContextException("Context {context} cannot be found".format(context=name))
+            contexts.append(context)
+        return contexts
+
+    @classmethod
+    def get_current_context(cls):
+        """Get current context.
+        Returns:
+            (Context): current context object.
+        """
+        return cls.get_context()
+
+    @classmethod
+    def set_current_context(cls, name="default"):
+        ctx = cls.get_context(name)
+        if not ctx:
+            raise errors.ContextNotFound(name)
+
+        err = write_context_name_to_docker_config(name)
+        if err:
+            raise errors.ContextException(
+                'Failed to set current context: {err}'.format(err=err))
+
+    @classmethod
+    def remove_context(cls, name):
+        """Remove a context. Similar to the ``docker context rm`` command.
+
+        Args:
+            name (str): The name of the context
+
+        Raises:
+            :py:class:`docker.errors.MissingContextParameter`
+                If a context name is not provided.
+            :py:class:`docker.errors.ContextNotFound`
+                If a context with the name does not exist.
+            :py:class:`docker.errors.ContextException`
+                If name is default.
+
+        Example:
+
+        >>> from docker.context import ContextAPI
+        >>> ContextAPI.remove_context(name='test')
+        >>>
+        """
+        if not name:
+            raise errors.MissingContextParameter("name")
+        if name == "default":
+            raise errors.ContextException(
+                'context "default" cannot be removed')
+        ctx = Context.load_context(name)
+        if not ctx:
+            raise errors.ContextNotFound(name)
+        if name == get_current_context_name():
+            write_context_name_to_docker_config(None)
+        ctx.remove()
+
+    @classmethod
+    def inspect_context(cls, name="default"):
+        """Inspect a context. Similar to the ``docker context inspect`` command.
+
+        Args:
+            name (str): The name of the context
+
+        Raises:
+            :py:class:`docker.errors.MissingContextParameter`
+                If a context name is not provided.
+            :py:class:`docker.errors.ContextNotFound`
+                If a context with the name does not exist.
+
+        Example:
+
+        >>> from docker.context import ContextAPI
+        >>> ContextAPI.remove_context(name='test')
+        >>>
+        """
+        if not name:
+            raise errors.MissingContextParameter("name")
+        if name == "default":
+            return cls.get_default_context()()
+        ctx = Context.load_context(name)
+        if not ctx:
+            raise errors.ContextNotFound(name)
+
+        return ctx()

plugins/module_utils/_api/context/config.py

@@ -0,0 +1,103 @@
+# -*- 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 hashlib
+import json
+import os
+
+from ..constants import DEFAULT_UNIX_SOCKET, IS_WINDOWS_PLATFORM
+from ..utils.config import find_config_file, get_default_config_file
+from ..utils.utils import parse_host
+
+METAFILE = "meta.json"
+
+
+def get_current_context_name_with_source():
+    if os.environ.get('DOCKER_HOST'):
+        return "default", "DOCKER_HOST environment variable set"
+    if os.environ.get('DOCKER_CONTEXT'):
+        return os.environ['DOCKER_CONTEXT'], "DOCKER_CONTEXT environment variable set"
+    docker_cfg_path = find_config_file()
+    if docker_cfg_path:
+        try:
+            with open(docker_cfg_path) as f:
+                return json.load(f).get("currentContext", "default"), "configuration file {file}".format(file=docker_cfg_path)
+        except Exception:
+            pass
+    return "default", "fallback value"
+
+
+def get_current_context_name():
+    return get_current_context_name_with_source()[0]
+
+
+def write_context_name_to_docker_config(name=None):
+    if name == 'default':
+        name = None
+    docker_cfg_path = find_config_file()
+    config = {}
+    if docker_cfg_path:
+        try:
+            with open(docker_cfg_path) as f:
+                config = json.load(f)
+        except Exception as e:
+            return e
+    current_context = config.get("currentContext", None)
+    if current_context and not name:
+        del config["currentContext"]
+    elif name:
+        config["currentContext"] = name
+    else:
+        return
+    if not docker_cfg_path:
+        docker_cfg_path = get_default_config_file()
+    try:
+        with open(docker_cfg_path, "w") as f:
+            json.dump(config, f, indent=4)
+    except Exception as e:
+        return e
+
+
+def get_context_id(name):
+    return hashlib.sha256(name.encode('utf-8')).hexdigest()
+
+
+def get_context_dir():
+    docker_cfg_path = find_config_file() or get_default_config_file()
+    return os.path.join(os.path.dirname(docker_cfg_path), "contexts")
+
+
+def get_meta_dir(name=None):
+    meta_dir = os.path.join(get_context_dir(), "meta")
+    if name:
+        return os.path.join(meta_dir, get_context_id(name))
+    return meta_dir
+
+
+def get_meta_file(name):
+    return os.path.join(get_meta_dir(name), METAFILE)
+
+
+def get_tls_dir(name=None, endpoint=""):
+    context_dir = get_context_dir()
+    if name:
+        return os.path.join(context_dir, "tls", get_context_id(name), endpoint)
+    return os.path.join(context_dir, "tls")
+
+
+def get_context_host(path=None, tls=False):
+    host = parse_host(path, IS_WINDOWS_PLATFORM, tls)
+    if host == DEFAULT_UNIX_SOCKET:
+        # remove http+ from default docker socket url
+        if host.startswith("http+"):
+            host = host[5:]
+    return host

plugins/module_utils/_api/context/context.py

@@ -0,0 +1,268 @@
+# -*- 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 json
+import os
+from shutil import copyfile, rmtree
+
+from ansible.module_utils.six import raise_from
+
+from ..errors import ContextException
+from ..tls import TLSConfig
+
+from .config import (
+    get_context_host,
+    get_meta_dir,
+    get_meta_file,
+    get_tls_dir,
+)
+
+
+IN_MEMORY = "IN MEMORY"
+
+
+class Context(object):
+    """A context."""
+
+    def __init__(self, name, orchestrator=None, host=None, endpoints=None,
+                 tls=False, description=None):
+        if not name:
+            raise Exception("Name not provided")
+        self.name = name
+        self.context_type = None
+        self.orchestrator = orchestrator
+        self.endpoints = {}
+        self.tls_cfg = {}
+        self.meta_path = IN_MEMORY
+        self.tls_path = IN_MEMORY
+        self.description = description
+
+        if not endpoints:
+            # set default docker endpoint if no endpoint is set
+            default_endpoint = "docker" if (
+                not orchestrator or orchestrator == "swarm"
+            ) else orchestrator
+
+            self.endpoints = {
+                default_endpoint: {
+                    "Host": get_context_host(host, tls),
+                    "SkipTLSVerify": not tls
+                }
+            }
+            return
+
+        # check docker endpoints
+        for k, v in endpoints.items():
+            if not isinstance(v, dict):
+                # unknown format
+                raise ContextException(
+                    "Unknown endpoint format for context {name}: {v}".format(name=name, v=v),
+                )
+
+            self.endpoints[k] = v
+            if k != "docker":
+                continue
+
+            self.endpoints[k]["Host"] = v.get("Host", get_context_host(
+                host, tls))
+            self.endpoints[k]["SkipTLSVerify"] = bool(v.get(
+                "SkipTLSVerify", not tls))
+
+    def set_endpoint(
+            self, name="docker", host=None, tls_cfg=None,
+            skip_tls_verify=False, def_namespace=None):
+        self.endpoints[name] = {
+            "Host": get_context_host(host, not skip_tls_verify),
+            "SkipTLSVerify": skip_tls_verify
+        }
+        if def_namespace:
+            self.endpoints[name]["DefaultNamespace"] = def_namespace
+
+        if tls_cfg:
+            self.tls_cfg[name] = tls_cfg
+
+    def inspect(self):
+        return self.__call__()
+
+    @classmethod
+    def load_context(cls, name):
+        meta = Context._load_meta(name)
+        if meta:
+            instance = cls(
+                meta["Name"],
+                orchestrator=meta["Metadata"].get("StackOrchestrator", None),
+                endpoints=meta.get("Endpoints", None),
+                description=meta.get('Description'))
+            instance.context_type = meta["Metadata"].get("Type", None)
+            instance._load_certs()
+            instance.meta_path = get_meta_dir(name)
+            return instance
+        return None
+
+    @classmethod
+    def _load_meta(cls, name):
+        meta_file = get_meta_file(name)
+        if not os.path.isfile(meta_file):
+            return None
+
+        metadata = {}
+        try:
+            with open(meta_file) as f:
+                metadata = json.load(f)
+        except (OSError, KeyError, ValueError) as e:
+            # unknown format
+            raise_from(Exception(
+                "Detected corrupted meta file for context {name} : {e}".format(name=name, e=e)
+            ), e)
+
+        # for docker endpoints, set defaults for
+        # Host and SkipTLSVerify fields
+        for k, v in metadata["Endpoints"].items():
+            if k != "docker":
+                continue
+            metadata["Endpoints"][k]["Host"] = v.get(
+                "Host", get_context_host(None, False))
+            metadata["Endpoints"][k]["SkipTLSVerify"] = bool(
+                v.get("SkipTLSVerify", True))
+
+        return metadata
+
+    def _load_certs(self):
+        certs = {}
+        tls_dir = get_tls_dir(self.name)
+        for endpoint in self.endpoints.keys():
+            if not os.path.isdir(os.path.join(tls_dir, endpoint)):
+                continue
+            ca_cert = None
+            cert = None
+            key = None
+            for filename in os.listdir(os.path.join(tls_dir, endpoint)):
+                if filename.startswith("ca"):
+                    ca_cert = os.path.join(tls_dir, endpoint, filename)
+                elif filename.startswith("cert"):
+                    cert = os.path.join(tls_dir, endpoint, filename)
+                elif filename.startswith("key"):
+                    key = os.path.join(tls_dir, endpoint, filename)
+            if all([ca_cert, cert, key]):
+                verify = None
+                if endpoint == "docker" and not self.endpoints["docker"].get(
+                        "SkipTLSVerify", False):
+                    verify = True
+                certs[endpoint] = TLSConfig(
+                    client_cert=(cert, key), ca_cert=ca_cert, verify=verify)
+        self.tls_cfg = certs
+        self.tls_path = tls_dir
+
+    def save(self):
+        meta_dir = get_meta_dir(self.name)
+        if not os.path.isdir(meta_dir):
+            os.makedirs(meta_dir)
+        with open(get_meta_file(self.name), "w") as f:
+            f.write(json.dumps(self.Metadata))
+
+        tls_dir = get_tls_dir(self.name)
+        for endpoint, tls in self.tls_cfg.items():
+            if not os.path.isdir(os.path.join(tls_dir, endpoint)):
+                os.makedirs(os.path.join(tls_dir, endpoint))
+
+            ca_file = tls.ca_cert
+            if ca_file:
+                copyfile(ca_file, os.path.join(
+                    tls_dir, endpoint, os.path.basename(ca_file)))
+
+            if tls.cert:
+                cert_file, key_file = tls.cert
+                copyfile(cert_file, os.path.join(
+                    tls_dir, endpoint, os.path.basename(cert_file)))
+                copyfile(key_file, os.path.join(
+                    tls_dir, endpoint, os.path.basename(key_file)))
+
+        self.meta_path = get_meta_dir(self.name)
+        self.tls_path = get_tls_dir(self.name)
+
+    def remove(self):
+        if os.path.isdir(self.meta_path):
+            rmtree(self.meta_path)
+        if os.path.isdir(self.tls_path):
+            rmtree(self.tls_path)
+
+    def __repr__(self):
+        return "<{classname}: '{name}'>".format(classname=self.__class__.__name__, name=self.name)
+
+    def __str__(self):
+        return json.dumps(self.__call__(), indent=2)
+
+    def __call__(self):
+        result = self.Metadata
+        result.update(self.TLSMaterial)
+        result.update(self.Storage)
+        return result
+
+    def is_docker_host(self):
+        return self.context_type is None
+
+    @property
+    def Name(self):
+        return self.name
+
+    @property
+    def Host(self):
+        if not self.orchestrator or self.orchestrator == "swarm":
+            endpoint = self.endpoints.get("docker", None)
+            if endpoint:
+                return endpoint.get("Host", None)
+            return None
+
+        return self.endpoints[self.orchestrator].get("Host", None)
+
+    @property
+    def Orchestrator(self):
+        return self.orchestrator
+
+    @property
+    def Metadata(self):
+        meta = {}
+        if self.orchestrator:
+            meta = {"StackOrchestrator": self.orchestrator}
+        return {
+            "Name": self.name,
+            "Metadata": meta,
+            "Endpoints": self.endpoints
+        }
+
+    @property
+    def TLSConfig(self):
+        key = self.orchestrator
+        if not key or key == "swarm":
+            key = "docker"
+        if key in self.tls_cfg.keys():
+            return self.tls_cfg[key]
+        return None
+
+    @property
+    def TLSMaterial(self):
+        certs = {}
+        for endpoint, tls in self.tls_cfg.items():
+            cert, key = tls.cert
+            certs[endpoint] = list(
+                map(os.path.basename, [tls.ca_cert, cert, key]))
+        return {
+            "TLSMaterial": certs
+        }
+
+    @property
+    def Storage(self):
+        return {
+            "Storage": {
+                "MetadataPath": self.meta_path,
+                "TLSPath": self.tls_path
+            }}

plugins/module_utils/_api/utils/config.py

@@ -22,12 +22,17 @@ LEGACY_DOCKER_CONFIG_FILENAME = '.dockercfg'
 log = logging.getLogger(__name__)
 
 
+def get_default_config_file():
+    return os.path.join(home_dir(), DOCKER_CONFIG_FILENAME)
+
+
 def find_config_file(config_path=None):
+    homedir = home_dir()
     paths = list(filter(None, [
         config_path,  # 1
         config_path_from_environment(),  # 2
-        os.path.join(home_dir(), DOCKER_CONFIG_FILENAME),  # 3
-        os.path.join(home_dir(), LEGACY_DOCKER_CONFIG_FILENAME),  # 4
+        os.path.join(homedir, DOCKER_CONFIG_FILENAME),  # 3
+        os.path.join(homedir, LEGACY_DOCKER_CONFIG_FILENAME),  # 4
     ]))
 
     log.debug("Trying paths: %s", repr(paths))

plugins/module_utils/_api/utils/utils.py

@@ -303,12 +303,7 @@ def parse_host(addr, is_win32=False, tls=False):
     if proto in ('tcp', 'ssh'):
         port = parsed_url.port or 0
         if port <= 0:
-            if proto != 'ssh':
-                raise errors.DockerException(
-                    'Invalid bind address format: port is required:'
-                    ' {0}'.format(addr)
-                )
-            port = 22
+            port = 22 if proto == 'ssh' else (2375 if tls else 2376)
             netloc = '{0}:{1}'.format(parsed_url.netloc, port)
 
         if not parsed_url.hostname:

plugins/module_utils/common.py

@@ -321,7 +321,7 @@ class AnsibleDockerClientBase(Client):
             cert_path=self._get_value('cert_path', params['client_cert'], 'DOCKER_CERT_PATH', None, type='str'),
             key_path=self._get_value('key_path', params['client_key'], 'DOCKER_CERT_PATH', None, type='str'),
             tls=self._get_value('tls', params['tls'], 'DOCKER_TLS', DEFAULT_TLS, type='bool'),
-            tls_verify=self._get_value('tls_verfy', params['validate_certs'], 'DOCKER_TLS_VERIFY',
+            tls_verify=self._get_value('validate_certs', params['validate_certs'], 'DOCKER_TLS_VERIFY',
                                        DEFAULT_TLS_VERIFY, type='bool'),
             timeout=self._get_value('timeout', params['timeout'], 'DOCKER_TIMEOUT',
                                     DEFAULT_TIMEOUT_SECONDS, type='int'),

plugins/module_utils/common_api.py

@@ -204,7 +204,7 @@ class AnsibleDockerClientBase(Client):
             cert_path=self._get_value('cert_path', params['client_cert'], 'DOCKER_CERT_PATH', None, type='str'),
             key_path=self._get_value('key_path', params['client_key'], 'DOCKER_CERT_PATH', None, type='str'),
             tls=self._get_value('tls', params['tls'], 'DOCKER_TLS', DEFAULT_TLS, type='bool'),
-            tls_verify=self._get_value('tls_verfy', params['validate_certs'], 'DOCKER_TLS_VERIFY',
+            tls_verify=self._get_value('validate_certs', params['validate_certs'], 'DOCKER_TLS_VERIFY',
                                        DEFAULT_TLS_VERIFY, type='bool'),
             timeout=self._get_value('timeout', params['timeout'], 'DOCKER_TIMEOUT',
                                     DEFAULT_TIMEOUT_SECONDS, type='int'),