add support for proxies

Signed-off-by: Corentin Henry <corentinhenry@gmail.com>

docker/api/build.py

@@ -168,8 +168,11 @@ class BuildApiMixin(object):
         }
         params.update(container_limits)
 
+        final_buildargs = self._proxy_configs.get_environment()
         if buildargs:
-            params.update({'buildargs': json.dumps(buildargs)})
+            final_buildargs.update(buildargs)
+        if final_buildargs:
+            params.update({'buildargs': json.dumps(final_buildargs)})
 
         if shmsize:
             if utils.version_gte(self._version, '1.22'):

docker/api/client.py

@@ -34,6 +34,7 @@ from ..transport import SSLAdapter, UnixAdapter
 from ..utils import utils, check_resource, update_headers, config
 from ..utils.socket import frames_iter, consume_socket_output, demux_adaptor
 from ..utils.json_stream import json_stream
+from ..utils.proxy import ProxyConfig
 try:
     from ..transport import NpipeAdapter
 except ImportError:
@@ -114,6 +115,12 @@ class APIClient(
         self.headers['User-Agent'] = user_agent
 
         self._general_configs = config.load_general_config()
+        try:
+            proxies = self._general_configs['proxies']['default']
+        except KeyError:
+            proxies = {}
+        self._proxy_configs = ProxyConfig.from_dict(proxies)
+
         self._auth_configs = auth.load_config(
             config_dict=self._general_configs, credstore_env=credstore_env,
         )

docker/api/container.py

@@ -403,6 +403,10 @@ class ContainerApiMixin(object):
         if isinstance(volumes, six.string_types):
             volumes = [volumes, ]
 
+        if isinstance(environment, dict):
+            environment = utils.utils.format_environment(environment)
+        environment = self._proxy_configs.inject_proxy_environment(environment)
+
         config = self.create_container_config(
             image, command, hostname, user, detach, stdin_open, tty,
             ports, environment, volumes,

docker/api/exec_api.py

@@ -50,6 +50,7 @@ class ExecApiMixin(object):
 
         if isinstance(environment, dict):
             environment = utils.utils.format_environment(environment)
+        environment = self._proxy_configs.inject_proxy_environment(environment)
 
         data = {
             'Container': container,

docker/utils/proxy.py

@@ -0,0 +1,69 @@
+from .utils import format_environment
+
+
+class ProxyConfig():
+    '''
+    Hold the client's proxy configuration
+    '''
+
+    def __init__(self, http=None, https=None, ftp=None, no_proxy=None):
+        self.http = http
+        self.https = https
+        self.ftp = ftp
+        self.no_proxy = no_proxy
+
+    @staticmethod
+    def from_dict(config):
+        '''
+        Instantiate a new ProxyConfig from a dictionary that represents a
+        client configuration, as described in `the documentation`_.
+
+        .. _the documentation:
+            https://docs.docker.com/network/proxy/#configure-the-docker-client
+        '''
+        return ProxyConfig(
+            http=config.get('httpProxy', None),
+            https=config.get('httpsProxy', None),
+            ftp=config.get('ftpProxy', None),
+            no_proxy=config.get('noProxy', None))
+
+    def get_environment(self):
+        '''
+        Return a dictionary representing the environment variables used to
+        set the proxy settings.
+        '''
+        env = {}
+        if self.http:
+            env['http_proxy'] = env['HTTP_PROXY'] = self.http
+        if self.https:
+            env['https_proxy'] = env['HTTPS_PROXY'] = self.https
+        if self.ftp:
+            env['ftp_proxy'] = env['FTP_PROXY'] = self.ftp
+        if self.no_proxy:
+            env['no_proxy'] = env['NO_PROXY'] = self.no_proxy
+        return env
+
+    def inject_proxy_environment(self, environment):
+        '''
+        Given a list of strings representing environment variables, prepend the
+        environemt variables corresponding to the proxy settings.
+        '''
+        if not self:
+            return environment
+
+        proxy_env = format_environment(self.get_environment())
+        if not environment:
+            return proxy_env
+        # It is important to prepend our variables, because we want the
+        # variables defined in "environment" to take precedence.
+        return proxy_env + environment
+
+    def __bool__(self):
+        return bool(self.http or self.https or self.ftp or self.no_proxy)
+
+    def __nonzero__(self):
+        return self.__bool__()
+
+    def __str__(self):
+        return 'ProxyConfig(http={}, https={}, ftp={}, no_proxy={})'.format(
+            self.http, self.https, self.ftp, self.no_proxy)