Implementation for /exec using websocket

inspired by the POC from @chekolyn

* Adds a new requirement on websocket-client
* Add a new class WSClient that uses WebSocketApp from
  the websocket-client.
* Make sure we pass Authorization header
* Make sure we honor the SSL settings in configuration
* Some of the code will get overwritten when we generate
  fresh classes from swagger definition. To remind us
  added a e2e test so we don't lose the changes
* Added a new configuration option to enable/disable failures
  when hostnames in certificates don't match

Fixes kubernetes-client#58

kubernetes/client/api_client.py

@@ -21,6 +21,7 @@
 from __future__ import absolute_import
 
 from . import models
+from . import ws_client
 from .rest import RESTClientObject
 from .rest import ApiException
 
@@ -343,6 +344,15 @@ def request(self, method, url, query_params=None, headers=None,
         """
         Makes the HTTP request using RESTClient.
         """
+        # FIXME(dims) : We need a better way to figure out which
+        # calls end up using web sockets
+        if url.endswith('/exec') and method == "GET":
+            return ws_client.GET(self.config,
+                                 url,
+                                 query_params=query_params,
+                                 _request_timeout=_request_timeout,
+                                 headers=headers)
+
         if method == "GET":
             return self.rest_client.GET(url,
                                         query_params=query_params,

kubernetes/client/ws_client.py

@@ -0,0 +1,114 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+from .rest import ApiException
+
+import certifi
+import collections
+import websocket
+import six
+import ssl
+from six.moves.urllib.parse import urlencode
+from six.moves.urllib.parse import quote_plus
+
+
+class WSClient:
+    def __init__(self, configuration, url, headers):
+        self.messages = []
+        self.errors = []
+        websocket.enableTrace(False)
+        header = None
+
+        # We just need to pass the Authorization, ignore all the other
+        # http headers we get from the generated code
+        if 'Authorization' in headers:
+            header = "Authorization: %s" % headers['Authorization']
+
+        self.ws = websocket.WebSocketApp(url,
+                                         on_message=self.on_message,
+                                         on_error=self.on_error,
+                                         on_close=self.on_close,
+                                         header=[header] if header else None)
+        self.ws.on_open = self.on_open
+
+        if url.startswith('wss://') and configuration.verify_ssl:
+            ssl_opts = {
+                'cert_reqs': ssl.CERT_REQUIRED,
+                'keyfile': configuration.key_file,
+                'certfile': configuration.cert_file,
+                'ca_certs': configuration.ssl_ca_cert or certifi.where(),
+            }
+            if configuration.assert_hostname is not None:
+                ssl_opts['check_hostname'] = configuration.assert_hostname
+        else:
+            ssl_opts = {'cert_reqs': ssl.CERT_NONE}
+
+        self.ws.run_forever(sslopt=ssl_opts)
+
+    def on_message(self, ws, message):
+        if message[0] == '\x01':
+            message = message[1:]
+        if message:
+            if six.PY3 and isinstance(message, six.binary_type):
+                message = message.decode('utf-8')
+            self.messages.append(message)
+
+    def on_error(self, ws, error):
+        self.errors.append(error)
+
+    def on_close(self, ws):
+        pass
+
+    def on_open(self, ws):
+        pass
+
+
+WSResponse = collections.namedtuple('WSResponse', ['data'])
+
+
+def GET(configuration, url, query_params, _request_timeout, headers):
+    # switch protocols from http to websocket
+    url = url.replace('http://', 'ws://')
+    url = url.replace('https://', 'wss://')
+
+    # patch extra /
+    url = url.replace('//api', '/api')
+
+    # Extract the command from the list of tuples
+    commands = None
+    for key, value in query_params:
+        if key == 'command':
+            commands = value
+            break
+
+    # drop command from query_params as we will be processing it separately
+    query_params = [(key, value) for key, value in query_params if
+                    key != 'command']
+
+    # if we still have query params then encode them
+    if query_params:
+        url += '?' + urlencode(query_params)
+
+    # tack on the actual command to execute at the end
+    if isinstance(commands, list):
+        for command in commands:
+            url += "&command=%s&" % quote_plus(command)
+    else:
+        url += '&command=' + quote_plus(commands)
+
+    client = WSClient(configuration, url, headers)
+    if client.errors:
+        raise ApiException(
+            status=0,
+            reason='\n'.join([str(error) for error in client.errors])
+        )
+    return WSResponse('%s' % ''.join(client.messages))

kubernetes/e2e_test/test_client.py

@@ -12,6 +12,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import time
 import unittest
 import uuid
 
@@ -34,22 +35,49 @@ def test_pod_apis(self):
         client = api_client.ApiClient(self.API_URL, config=self.config)
         api = core_v1_api.CoreV1Api(client)
 
-        name = 'test-' + str(uuid.uuid4())
-        pod_manifest = {'apiVersion': 'v1',
-                        'kind': 'Pod',
-                        'metadata': {'color': 'blue', 'name': name},
-                        'spec': {'containers': [{'image': 'dockerfile/redis',
-                                                 'name': 'redis'}]}}
+        name = 'busybox-test-' + str(uuid.uuid4())
+        pod_manifest = {
+            'apiVersion': 'v1',
+            'kind': 'Pod',
+            'metadata': {
+                'name': name
+            },
+            'spec': {
+                'containers': [{
+                    'image': 'busybox',
+                    'name': 'sleep',
+                    "args": [
+                        "/bin/sh",
+                        "-c",
+                        "while true;do date;sleep 5; done"
+                    ]
+                }]
+            }
+        }
 
         resp = api.create_namespaced_pod(body=pod_manifest,
                                          namespace='default')
         self.assertEqual(name, resp.metadata.name)
         self.assertTrue(resp.status.phase)
 
-        resp = api.read_namespaced_pod(name=name,
-                                       namespace='default')
-        self.assertEqual(name, resp.metadata.name)
-        self.assertTrue(resp.status.phase)
+        while True:
+            resp = api.read_namespaced_pod(name=name,
+                                           namespace='default')
+            self.assertEqual(name, resp.metadata.name)
+            self.assertTrue(resp.status.phase)
+            if resp.status.phase != 'Pending':
+                break
+            time.sleep(1)
+
+        exec_command = ['/bin/sh',
+                        '-c',
+                        'for i in $(seq 1 3); do date; sleep 1; done']
+        resp = api.connect_get_namespaced_pod_exec(name, 'default',
+                                                   command=exec_command,
+                                                   stderr=False, stdin=False,
+                                                   stdout=True, tty=False)
+        print('EXEC response : %s' % resp)
+        self.assertEqual(3, len(resp.splitlines()))
 
         number_of_pods = len(api.list_pod_for_all_namespaces().items)
         self.assertTrue(number_of_pods > 0)

requirements.txt

@@ -1,9 +1,9 @@
 certifi >= 14.05.14
-six == 1.8.0
+six>=1.9.0
 python_dateutil >= 2.5.3
 setuptools >= 21.0.0
 urllib3 >= 1.19.1
 pyyaml >= 3.12
 oauth2client >= 4.0.0
 ipaddress >= 1.0.17
-
+websocket-client>=0.32.0

tox.ini

@@ -6,6 +6,7 @@ passenv = TOXENV CI TRAVIS TRAVIS_*
 usedevelop = True
 install_command = pip install -U {opts} {packages}
 deps = -r{toxinidir}/test-requirements.txt
+       -r{toxinidir}/requirements.txt
 commands =
    python -V
    nosetests []