Unittests for portforwarding ability added in python-base.

examples/pod_portforward.py

@@ -0,0 +1,194 @@
+# Copyright 2020 The Kubernetes Authors.
+#
+# 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.
+
+"""
+Shows the functionality of portforward streaming using an nginx container.
+"""
+
+import select
+import socket
+import time
+import urllib.request
+
+from kubernetes import config
+from kubernetes.client import Configuration
+from kubernetes.client.api import core_v1_api
+from kubernetes.client.rest import ApiException
+from kubernetes.stream import portforward
+
+##############################################################################
+# Kubernetes pod port forwarding works by directly providing a socket which
+# the python application uses to send and receive data on. This is in contrast
+# to the go client, which opens a local port that the go application then has
+# to open to get a socket to transmit data.
+#
+# This simplifies the python application, there is not local port to worry
+# about if that port number is available. Nor does the python application have
+# to then deal with opening this local port. The socket used to transmit data
+# is immediately provided to the python application.
+#
+# Below also is an example of monkey patching the socket.create_connection
+# function so that DNS names of the following formats will access kubernetes
+# ports:
+#
+#    <pod-name>.<namespace>.kubernetes
+#    <pod-name>.pod.<namespace>.kubernetes
+#    <service-name>.svc.<namespace>.kubernetes
+#    <service-name>.service.<namespace>.kubernetes
+#
+# These DNS name can be used to interact with pod ports using python libraries,
+# such as urllib.request and http.client. For example:
+#
+# response = urllib.request.urlopen(
+#     'https://metrics-server.service.kube-system.kubernetes/'
+# )
+#
+##############################################################################
+
+
+def portforward_commands(api_instance):
+    name = 'portforward-example'
+    resp = None
+    try:
+        resp = api_instance.read_namespaced_pod(name=name,
+                                                namespace='default')
+    except ApiException as e:
+        if e.status != 404:
+            print("Unknown error: %s" % e)
+            exit(1)
+
+    if not resp:
+        print("Pod %s does not exist. Creating it..." % name)
+        pod_manifest = {
+            'apiVersion': 'v1',
+            'kind': 'Pod',
+            'metadata': {
+                'name': name
+            },
+            'spec': {
+                'containers': [{
+                    'image': 'nginx',
+                    'name': 'nginx',
+                }]
+            }
+        }
+        api_instance.create_namespaced_pod(body=pod_manifest,
+                                           namespace='default')
+        while True:
+            resp = api_instance.read_namespaced_pod(name=name,
+                                                    namespace='default')
+            if resp.status.phase != 'Pending':
+                break
+            time.sleep(1)
+        print("Done.")
+
+    pf = portforward(
+        api_instance.connect_get_namespaced_pod_portforward,
+        name, 'default',
+        ports='80',
+    )
+    http = pf.socket(80)
+    http.setblocking(True)
+    http.sendall(b'GET / HTTP/1.1\r\n')
+    http.sendall(b'Host: 127.0.0.1\r\n')
+    http.sendall(b'Connection: close\r\n')
+    http.sendall(b'Accept: */*\r\n')
+    http.sendall(b'\r\n')
+    response = b''
+    while True:
+        select.select([http], [], [])
+        data = http.recv(1024)
+        if not data:
+            break
+        response += data
+    http.close()
+    print(response.decode('utf-8'))
+    error = pf.error(80)
+    if error is None:
+        print("No port forward errors on port 80.")
+    else:
+        print("Port 80 has the following error: %s" % error)
+
+    # Monkey patch socket.create_connection which is used by http.client and
+    # urllib.request. The same can be done with urllib3.util.connection.create_connection
+    # if the "requests" package is used.
+    socket_create_connection = socket.create_connection
+    def kubernetes_create_connection(address, *args, **kwargs):
+        dns_name = address[0]
+        if isinstance(dns_name, bytes):
+            dns_name = dns_name.decode()
+        dns_name = dns_name.split(".")
+        if dns_name[-1] != 'kubernetes':
+            return socket_create_connection(address, *args, **kwargs)
+        if len(dns_name) not in (3, 4):
+            raise RuntimeError("Unexpected kubernetes DNS name.")
+        namespace = dns_name[-2]
+        name = dns_name[0]
+        port = address[1]
+        if len(dns_name) == 4:
+            if dns_name[1] in ('svc', 'service'):
+                service = api_instance.read_namespaced_service(name, namespace)
+                for service_port in service.spec.ports:
+                    if service_port.port == port:
+                        port = service_port.target_port
+                        break
+                else:
+                    raise RuntimeError("Unable to find service port: %s" % port)
+                label_selector = []
+                for key, value in service.spec.selector.items():
+                    label_selector.append("%s=%s" % (key, value))
+                pods = api_instance.list_namespaced_pod(
+                    namespace, label_selector=",".join(label_selector)
+                )
+                if not pods.items:
+                    raise RuntimeError("Unable to find service pods.")
+                name = pods.items[0].metadata.name
+                if isinstance(port, str):
+                    for container in pods.items[0].spec.containers:
+                        for container_port in container.ports:
+                            if container_port.name == port:
+                                port = container_port.container_port
+                                break
+                        else:
+                            continue
+                        break
+                    else:
+                        raise RuntimeError("Unable to find service port name: %s" % port)
+            elif dns_name[1] != 'pod':
+                raise RuntimeError("Unsupported resource type: %s" % dns_name[1])
+        pf = portforward(api_instance.connect_get_namespaced_pod_portforward,
+                         name, namespace, ports=str(port))
+        return pf.socket(port)
+    socket.create_connection = kubernetes_create_connection
+
+    # Access the nginx http server using the "<pod-name>.pod.<namespace>.kubernetes" dns name.
+    response = urllib.request.urlopen('http://%s.pod.default.kubernetes' % name)
+    html = response.read().decode('utf-8')
+    response.close()
+    print('Status:', response.status)
+    print(html)
+
+
+def main():
+    config.load_kube_config()
+    c = Configuration.get_default_copy()
+    c.assert_hostname = False
+    Configuration.set_default(c)
+    core_v1 = core_v1_api.CoreV1Api()
+
+    portforward_commands(core_v1)
+
+
+if __name__ == '__main__':
+    main()

kubernetes/e2e_test/test_client.py

@@ -13,14 +13,17 @@
 # under the License.
 
 import json
+import select
+import socket
 import time
 import unittest
+import urllib.request
 import uuid
 
 from kubernetes.client import api_client
 from kubernetes.client.api import core_v1_api
 from kubernetes.e2e_test import base
-from kubernetes.stream import stream
+from kubernetes.stream import stream, portforward
 from kubernetes.stream.ws_client import ERROR_CHANNEL
 
 
@@ -119,6 +122,7 @@ def test_pod_apis(self):
 
         resp = api.delete_namespaced_pod(name=name, body={},
                                          namespace='default')
+
     def test_exit_code(self):
         client = api_client.ApiClient(configuration=self.config)
         api = core_v1_api.CoreV1Api(client)
@@ -159,6 +163,146 @@ def test_exit_code(self):
         resp = api.delete_namespaced_pod(name=name, body={},
                                          namespace='default')
 
+    def test_portforward_raw(self):
+        client = api_client.ApiClient(configuration=self.config)
+        api = core_v1_api.CoreV1Api(client)
+
+        name = 'portforward-raw-' + short_uuid()
+        pod_manifest = manifest_with_command(
+            name,
+            'for port in 1234 1235;do ((while true;do nc -l -p $port -e /bin/cat; done)&);done;sleep 60',
+        )
+        resp = api.create_namespaced_pod(body=pod_manifest,
+                                         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)
+
+        pf = portforward(api.connect_get_namespaced_pod_portforward,
+                         name, 'default',
+                         ports='1234,1235')
+        sock1234 = pf.socket(1234)
+        sock1235 = pf.socket(1235)
+        sock1234.setblocking(True)
+        sock1235.setblocking(True)
+        sent1234 = b'Test port 1234 forwarding...'
+        sent1235 = b'Test port 1235 forwarding...'
+        sock1234.sendall(sent1234)
+        sock1235.sendall(sent1235)
+        reply1234 = b''
+        reply1235 = b''
+        while True:
+            rlist = []
+            if sock1234.fileno() != -1:
+                rlist.append(sock1234)
+            if sock1235.fileno() != -1:
+                rlist.append(sock1235)
+            if not rlist:
+                break
+            r, _w, _x = select.select(rlist, [], [], 1)
+            if not r:
+                break
+            if sock1234 in r:
+                data = sock1234.recv(1024)
+                if data:
+                    reply1234 += data
+                else:
+                    assert False, 'Unexpected sock1234 close'
+            if sock1235 in r:
+                data = sock1235.recv(1024)
+                if data:
+                    reply1235 += data
+                else:
+                    assert False, 'Unexpected sock1235 close'
+        self.assertEqual(reply1234, sent1234)
+        self.assertEqual(reply1235, sent1235)
+        for sock in (sock1234, sock1235):
+            sent = b'Another test using fileno %s' % str(sock.fileno()).encode()
+            sock.sendall(sent)
+            reply = b''
+            while True:
+                r, _w, _x = select.select([sock], [], [], 1)
+                if not r:
+                    break
+                data = sock.recv(1024)
+                if data:
+                    reply += data
+                else:
+                    assert False, 'Unexpected sock close'
+            self.assertEqual(reply, sent)
+            sock.close()
+        self.assertIsNone(pf.error(1234))
+        self.assertIsNone(pf.error(1235))
+
+        resp = api.delete_namespaced_pod(name=name, body={},
+                                         namespace='default')
+
+    def test_portforward_http(self):
+        client = api_client.ApiClient(configuration=self.config)
+        api = core_v1_api.CoreV1Api(client)
+
+        name = 'portforward-http-' +  short_uuid()
+        pod_manifest = {
+            'apiVersion': 'v1',
+            'kind': 'Pod',
+            'metadata': {
+                'name': name
+            },
+            'spec': {
+                'containers': [{
+                    'name': 'nginx',
+                    'image': 'nginx',
+                }]
+            }
+        }
+
+        resp = api.create_namespaced_pod(body=pod_manifest,
+                                         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)
+
+        def kubernetes_create_connection(address, *args, **kwargs):
+            dns_name = address[0]
+            if isinstance(dns_name, bytes):
+                dns_name = dns_name.decode()
+            dns_name = dns_name.split(".")
+            if len(dns_name) != 3 or dns_name[2] != "kubernetes":
+                return socket_create_connection(address, *args, **kwargs)
+            pf = portforward(api.connect_get_namespaced_pod_portforward,
+                             dns_name[0], dns_name[1], ports=str(address[1]))
+            return pf.socket(address[1])
+
+        socket_create_connection = socket.create_connection
+        try:
+            socket.create_connection = kubernetes_create_connection
+            response = urllib.request.urlopen('http://%s.default.kubernetes/' % name)
+            html = response.read().decode('utf-8')
+        finally:
+            socket.create_connection = socket_create_connection
+
+        self.assertEqual(response.status, 200)
+        self.assertTrue('<h1>Welcome to nginx!</h1>' in html)
+
+        resp = api.delete_namespaced_pod(name=name, body={},
+                                         namespace='default')
+
     def test_service_apis(self):
         client = api_client.ApiClient(configuration=self.config)
         api = core_v1_api.CoreV1Api(client)