Allow cancelling the streams from other threads

Signed-off-by: Viktor Adam <rycus86@gmail.com>

docker/api/container.py

@@ -5,7 +5,8 @@ from .. import errors
 from .. import utils
 from ..constants import DEFAULT_DATA_CHUNK_SIZE
 from ..types import (
-    ContainerConfig, EndpointConfig, HostConfig, NetworkingConfig
+    CancellableStream, ContainerConfig, EndpointConfig, HostConfig,
+    NetworkingConfig
 )
 
 
@@ -52,10 +53,15 @@ class ContainerApiMixin(object):
         u = self._url("/containers/{0}/attach", container)
         response = self._post(u, headers=headers, params=params, stream=True)
 
-        return self._read_from_socket(
+        output = self._read_from_socket(
             response, stream, self._check_is_tty(container)
         )
 
+        if stream:
+            return CancellableStream(output, response)
+        else:
+            return output
+
     @utils.check_resource('container')
     def attach_socket(self, container, params=None, ws=False):
         """
@@ -815,7 +821,12 @@ class ContainerApiMixin(object):
 
         url = self._url("/containers/{0}/logs", container)
         res = self._get(url, params=params, stream=stream)
-        return self._get_result(container, stream, res)
+        output = self._get_result(container, stream, res)
+
+        if stream:
+            return CancellableStream(output, res)
+        else:
+            return output
 
     @utils.check_resource('container')
     def pause(self, container):

docker/api/daemon.py

 import os
 from datetime import datetime
 
-from .. import auth, utils
+from .. import auth, types, utils
 
 
 class DaemonApiMixin(object):
@@ -34,8 +34,7 @@ class DaemonApiMixin(object):
                 the fly. False by default.
 
         Returns:
-            (generator): A blocking generator you can iterate over to retrieve
-                events as they happen.
+            A :py:class:`docker.types.daemon.CancellableStream` generator
 
         Raises:
             :py:class:`docker.errors.APIError`
@@ -50,6 +49,14 @@ class DaemonApiMixin(object):
              u'status': u'start',
              u'time': 1423339459}
             ...
+
+            or
+
+            >>> events = client.events()
+            >>> for event in events:
+            ...   print event
+            >>> # and cancel from another thread
+            >>> events.close()
         """
 
         if isinstance(since, datetime):
@@ -68,10 +75,10 @@ class DaemonApiMixin(object):
         }
         url = self._url('/events')
 
-        return self._stream_helper(
-            self._get(url, params=params, stream=True, timeout=None),
-            decode=decode
-        )
+        response = self._get(url, params=params, stream=True, timeout=None)
+        stream = self._stream_helper(response, decode=decode)
+
+        return types.CancellableStream(stream, response)
 
     def info(self):
         """

docker/types/__init__.py

 # flake8: noqa
 from .containers import ContainerConfig, HostConfig, LogConfig, Ulimit
+from .daemon import CancellableStream
 from .healthcheck import Healthcheck
 from .networks import EndpointConfig, IPAMConfig, IPAMPool, NetworkingConfig
 from .services import (

docker/types/daemon.py

+import socket
+
+try:
+    import requests.packages.urllib3 as urllib3
+except ImportError:
+    import urllib3
+
+
+class CancellableStream(object):
+    """
+    Stream wrapper for real-time events, logs, etc. from the server.
+
+    Example:
+        >>> events = client.events()
+        >>> for event in events:
+        ...   print event
+        >>> # and cancel from another thread
+        >>> events.close()
+    """
+
+    def __init__(self, stream, response):
+        self._stream = stream
+        self._response = response
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        try:
+            return next(self._stream)
+        except urllib3.exceptions.ProtocolError:
+            raise StopIteration
+        except socket.error:
+            raise StopIteration
+
+    next = __next__
+
+    def close(self):
+        """
+        Closes the event streaming.
+        """
+
+        if not self._response.raw.closed:
+            # find the underlying socket object
+            # based on api.client._get_raw_response_socket
+
+            sock_fp = self._response.raw._fp.fp
+
+            if hasattr(sock_fp, 'raw'):
+                sock_raw = sock_fp.raw
+
+                if hasattr(sock_raw, 'sock'):
+                    sock = sock_raw.sock
+
+                elif hasattr(sock_raw, '_sock'):
+                    sock = sock_raw._sock
+
+            else:
+                sock = sock_fp._sock
+
+            sock.shutdown(socket.SHUT_RDWR)
+            sock.makefile().close()
+            sock.close()

tests/integration/api_container_test.py

@@ -2,6 +2,7 @@ import os
 import re
 import signal
 import tempfile
+import threading
 from datetime import datetime
 
 import docker
@@ -880,6 +881,30 @@ Line2'''
 
         assert logs == (snippet + '\n').encode(encoding='ascii')
 
+    def test_logs_streaming_and_follow_and_cancel(self):
+        snippet = 'Flowering Nights (Sakuya Iyazoi)'
+        container = self.client.create_container(
+            BUSYBOX, 'sh -c "echo \\"{0}\\" && sleep 3"'.format(snippet)
+        )
+        id = container['Id']
+        self.tmp_containers.append(id)
+        self.client.start(id)
+        logs = six.binary_type()
+
+        generator = self.client.logs(id, stream=True, follow=True)
+
+        exit_timer = threading.Timer(3, os._exit, args=[1])
+        exit_timer.start()
+
+        threading.Timer(1, generator.close).start()
+
+        for chunk in generator:
+            logs += chunk
+
+        exit_timer.cancel()
+
+        assert logs == (snippet + '\n').encode(encoding='ascii')
+
     def test_logs_with_dict_instead_of_id(self):
         snippet = 'Flowering Nights (Sakuya Iyazoi)'
         container = self.client.create_container(
@@ -1226,6 +1251,29 @@ class AttachContainerTest(BaseAPIIntegrationTest):
         output = self.client.attach(container, stream=False, logs=True)
         assert output == 'hello\n'.encode(encoding='ascii')
 
+    def test_attach_stream_and_cancel(self):
+        container = self.client.create_container(
+            BUSYBOX, 'sh -c "echo hello && sleep 60"',
+            tty=True
+        )
+        self.tmp_containers.append(container)
+        self.client.start(container)
+        output = self.client.attach(container, stream=True, logs=True)
+
+        exit_timer = threading.Timer(3, os._exit, args=[1])
+        exit_timer.start()
+
+        threading.Timer(1, output.close).start()
+
+        lines = []
+        for line in output:
+            lines.append(line)
+
+        exit_timer.cancel()
+
+        assert len(lines) == 1
+        assert lines[0] == 'hello\r\n'.encode(encoding='ascii')
+
     def test_detach_with_default(self):
         container = self.client.create_container(
             BUSYBOX, 'cat',

tests/integration/client_test.py

+import threading
 import unittest
 
 import docker
 
+from datetime import datetime, timedelta
+
 from ..helpers import requires_api_version
 from .base import TEST_API_VERSION
 
@@ -27,3 +30,20 @@ class ClientTest(unittest.TestCase):
         assert 'Containers' in data
         assert 'Volumes' in data
         assert 'Images' in data
+
+
+class CancellableEventsTest(unittest.TestCase):
+    client = docker.from_env(version=TEST_API_VERSION)
+
+    def test_cancel_events(self):
+        start = datetime.now()
+
+        events = self.client.events(until=start + timedelta(seconds=5))
+
+        cancel_thread = threading.Timer(2, events.close)
+        cancel_thread.start()
+
+        for _ in events:
+            pass
+
+        self.assertLess(datetime.now() - start, timedelta(seconds=3))

tests/integration/models_containers_test.py

+import os
 import tempfile
+import threading
 
 import docker
 import pytest
@@ -141,6 +143,25 @@ class ContainerCollectionTest(BaseIntegrationTest):
         assert logs[0] == b'hello\n'
         assert logs[1] == b'world\n'
 
+    def test_run_with_streamed_logs_and_cancel(self):
+        client = docker.from_env(version=TEST_API_VERSION)
+        out = client.containers.run(
+            'alpine', 'sh -c "echo hello && echo world"', stream=True
+        )
+
+        exit_timer = threading.Timer(3, os._exit, args=[1])
+        exit_timer.start()
+
+        threading.Timer(1, out.close).start()
+
+        logs = [line for line in out]
+
+        exit_timer.cancel()
+
+        assert len(logs) == 2
+        assert logs[0] == b'hello\n'
+        assert logs[1] == b'world\n'
+
     def test_get(self):
         client = docker.from_env(version=TEST_API_VERSION)
         container = client.containers.run("alpine", "sleep 300", detach=True)