Merge pull request docker#2495 from aiordache/issue#28_compose_contex…

…t_target

Implement docker contexts

.travis.yml

@@ -15,6 +15,6 @@ matrix:
     - env: TOXENV=flake8
 
 install:
-    - pip install tox
+    - pip install tox==2.9.1
 script:
     - tox

appveyor.yml

@@ -1,8 +1,9 @@
 version: '{branch}-{build}'
 
 install:
-  - "SET PATH=C:\\Python27-x64;C:\\Python27-x64\\Scripts;%PATH%"
+  - "SET PATH=C:\\Python37-x64;C:\\Python37-x64\\Scripts;%PATH%"
   - "python --version"
+  - "python -m pip install --upgrade pip"
   - "pip install tox==2.9.1"
 
 # Build the binary after tests

docker/__init__.py

@@ -1,6 +1,9 @@
 # flake8: noqa
 from .api import APIClient
 from .client import DockerClient, from_env
+from .context import Context
+from .context import ContextAPI
+from .tls import TLSConfig
 from .version import version, version_info
 
 __version__ = version

docker/constants.py

@@ -9,6 +9,18 @@
     'memory', 'memswap', 'cpushares', 'cpusetcpus'
 ]
 
+DEFAULT_HTTP_HOST = "127.0.0.1"
+DEFAULT_UNIX_SOCKET = "http+unix:///var/run/docker.sock"
+DEFAULT_NPIPE = 'npipe:////./pipe/docker_engine'
+
+BYTE_UNITS = {
+    'b': 1,
+    'k': 1024,
+    'm': 1024 * 1024,
+    'g': 1024 * 1024 * 1024
+}
+
+
 INSECURE_REGISTRY_DEPRECATION_WARNING = \
     'The `insecure_registry` argument to {} ' \
     'is deprecated and non-functional. Please remove it.'

docker/context/__init__.py

@@ -0,0 +1,3 @@
+# flake8: noqa
+from .context import Context
+from .api import ContextAPI

docker/context/api.py

@@ -0,0 +1,205 @@
+import json
+import os
+
+from docker import errors
+from docker.context.config import get_meta_dir
+from docker.context.config import METAFILE
+from docker.context.config import get_current_context_name
+from docker.context.config import write_context_name_to_docker_config
+from docker.context import Context
+
+
+class ContextAPI(object):
+    """Context API.
+    Contains methods for context management:
+    create, list, remove, get, inspect.
+    """
+    DEFAULT_CONTEXT = Context("default")
+
+    @classmethod
+    def create_context(
+            cls, name, orchestrator="swarm", 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": {
+                "StackOrchestrator": "swarm"
+            },
+            "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 == "swarm" else 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": {
+                "StackOrchestrator": "swarm"
+            },
+            "Endpoints": {
+                "docker": {
+                "Host": "unix:///var/run/docker.sock",
+                "SkipTLSVerify": false
+                }
+            }
+        }
+        """
+        if not name:
+            name = get_current_context_name()
+        if name == "default":
+            return cls.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 the server returns an error.
+        """
+        names = []
+        for dirname, dirnames, fnames in os.walk(get_meta_dir()):
+            for filename in fnames + dirnames:
+                if filename == METAFILE:
+                    try:
+                        data = json.load(
+                            open(os.path.join(dirname, filename), "r"))
+                        names.append(data["Name"])
+                    except Exception as e:
+                        raise errors.ContextException(
+                            "Failed to load metafile {}: {}".format(
+                                filename, e))
+
+        contexts = [cls.DEFAULT_CONTEXT]
+        for name in names:
+            contexts.append(Context.load_context(name))
+        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: {}'.format(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"):
+        """Remove 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.DEFAULT_CONTEXT()
+        ctx = Context.load_context(name)
+        if not ctx:
+            raise errors.ContextNotFound(name)
+
+        return ctx()

docker/context/config.py

@@ -0,0 +1,81 @@
+import os
+import json
+import hashlib
+
+from docker import utils
+from docker.constants import IS_WINDOWS_PLATFORM
+from docker.constants import DEFAULT_UNIX_SOCKET
+from docker.utils.config import find_config_file
+
+METAFILE = "meta.json"
+
+
+def get_current_context_name():
+    name = "default"
+    docker_cfg_path = find_config_file()
+    if docker_cfg_path:
+        try:
+            with open(docker_cfg_path, "r") as f:
+                name = json.load(f).get("currentContext", "default")
+        except Exception:
+            return "default"
+    return name
+
+
+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, "r") 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
+    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():
+    return os.path.join(os.path.dirname(find_config_file() or ""), "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):
+    host = utils.parse_host(path, IS_WINDOWS_PLATFORM)
+    if host == DEFAULT_UNIX_SOCKET:
+        # remove http+ from default docker socket url
+        return host.strip("http+")
+    return host