pylxd.Client() raises ValueError if e.g. http_proxy environment variable is set about pylxd

[rockstar]

pylxd isn't collecting any proxy information (presumably because requests usually Just Works). This is probably a bug in requests_unixsocket, but since it affects pylxd, it's worth our time to try and track it down.

[moreati]

Looks like the behaviour was introduced relatively recently, after requests 2.9.1 and requests-unixsocket 0.1.5 (as shipped in Ubuntu 16.04).

from __future__ import print_function

import os
import sys

import pkg_resources
import requests
import requests_unixsocket

SOCKET_URL = 'http+unix://%2Fvar%2Flib%2Flxd%2Funix.socket'

print('HTTP_PROXY:', os.environ['HTTP_PROXY'])
print('sys.version:', sys.version.replace('\n', ' '))
print('requests.__version__', requests.__version__)
print('requests_unixsocket versions', pkg_resources.get_distribution('requests_unixsocket').version)

unixsocket_session = requests_unixsocket.Session()
print('unixsocket_session.get:', unixsocket_session.get(SOCKET_URL))

requests_unixsocket.monkeypatch()
print('requests.get:', requests.get(SOCKET_URL))

alex@martha:/tmp$ HTTP_PROXY=foo python foo.py 
HTTP_PROXY: foo
sys.version: 2.7.11+ (default, Apr 17 2016, 14:00:29)  [GCC 5.3.1 20160413]
requests.__version__ 2.9.1
requests_unixsocket versions 0.1.5
unixsocket_session.get: <Response [200]>
requests.get: <Response [200]>

[moreati]

The latest released versions (requests 2.10.0, requests-unixsocket 0.1.5) do not trigger the behaviour

alex@martha:/tmp$ virtualenv v
Running virtualenv with interpreter /usr/bin/python2
New python executable in /tmp/v/bin/python2
Also creating executable in /tmp/v/bin/python
Installing setuptools, pkg_resources, pip, wheel...done.
alex@martha:/tmp$ v/bin/pip install requests requests_unixsocket
Collecting requests
  Using cached requests-2.10.0-py2.py3-none-any.whl
Collecting requests_unixsocket
  Downloading requests-unixsocket-0.1.5.tar.gz
Collecting urllib3>=1.8 (from requests_unixsocket)
  Using cached urllib3-1.16-py2.py3-none-any.whl
Building wheels for collected packages: requests-unixsocket
  Running setup.py bdist_wheel for requests-unixsocket ... done
  Stored in directory: /home/alex/.cache/pip/wheels/fa/a2/48/cd582e716aa8699b605b6976914744a46b8e8e17a9974380f9
Successfully built requests-unixsocket
Installing collected packages: requests, urllib3, requests-unixsocket
Successfully installed requests-2.10.0 requests-unixsocket-0.1.5 urllib3-1.16

alex@martha:/tmp$ HTTP_PROXY=http://localhost v/bin/python foo.py
HTTP_PROXY: http://localhost
sys.version: 2.7.11+ (default, Apr 17 2016, 14:00:29)  [GCC 5.3.1 20160413]
requests.__version__ 2.10.0
requests_unixsocket versions 0.1.5
unixsocket_session.get: <Response [200]>
requests.get: <Response [200]>

[moreati]

Installing pylxd 2.0.2 downgrades from requests-unixsocket 0.1.5 to 0.1.4. Now this bug is triggered

alex@martha:/tmp$ v/bin/pip install pylxd
Collecting pylxd
Collecting ws4py>=0.3.4 (from pylxd)
  Using cached ws4py-0.3.5-py2-none-any.whl
Collecting pbr>=1.6 (from pylxd)
  Using cached pbr-1.10.0-py2.py3-none-any.whl
Collecting requests-unixsocket==0.1.4 (from pylxd)
Requirement already satisfied (use --upgrade to upgrade): requests!=2.8.0,>=2.5.2 in ./v/lib/python2.7/site-packages (from pylxd)
Collecting python-dateutil>=2.4.2 (from pylxd)
  Using cached python_dateutil-2.5.3-py2.py3-none-any.whl
Collecting six>=1.9.0 (from pylxd)
  Using cached six-1.10.0-py2.py3-none-any.whl
Installing collected packages: ws4py, pbr, requests-unixsocket, six, python-dateutil, pylxd
  Found existing installation: requests-unixsocket 0.1.5
    Uninstalling requests-unixsocket-0.1.5:
      Successfully uninstalled requests-unixsocket-0.1.5
Successfully installed pbr-1.10.0 pylxd-2.0.2 python-dateutil-2.5.3 requests-unixsocket-0.1.4 six-1.10.0 ws4py-0.3.5

alex@martha:/tmp$ HTTP_PROXY=http://localhost v/bin/python foo.py
HTTP_PROXY: http://localhost
sys.version: 2.7.11+ (default, Apr 17 2016, 14:00:29)  [GCC 5.3.1 20160413]
requests.__version__ 2.10.0
requests_unixsocket version 0.1.4
Traceback (most recent call last):
  File "foo.py", line 18, in <module>
    print('unixsocket_session.get:', unixsocket_session.get(SOCKET_URL))
  File "/tmp/v/local/lib/python2.7/site-packages/requests/sessions.py", line 487, in get
    return self.request('GET', url, **kwargs)
  File "/tmp/v/local/lib/python2.7/site-packages/requests/sessions.py", line 475, in request
    resp = self.send(prep, **send_kwargs)
  File "/tmp/v/local/lib/python2.7/site-packages/requests/sessions.py", line 585, in send
    r = adapter.send(request, **kwargs)
  File "/tmp/v/local/lib/python2.7/site-packages/requests/adapters.py", line 370, in send
    conn = self.get_connection(request.url, proxies)
  File "/tmp/v/local/lib/python2.7/site-packages/requests_unixsocket/adapters.py", line 53, in get_connection
    % self.__class__.__name__)
ValueError: UnixAdapter does not support specifying proxies

[moreati]

It was fixed in python-unixsocket by msabramo/requests-unixsocket@20f4324, merged in msabramo/requests-unixsocket#14. I'll submit a PR to update the dependency.