certificate verify failed when REQUESTS_CA_BUNDLE environment variable is set

[jmaroeder]

When the REQUESTS_CA_BUNDLE environment variable is set, pykube is unable to connect to a server:

  File "/usr/lib/python3.6/site-packages/urllib3/connectionpool.py", line 601, in urlopen
    chunked=chunked)
  File "/usr/lib/python3.6/site-packages/urllib3/connectionpool.py", line 346, in _make_request
    self._validate_conn(conn)
  File "/usr/lib/python3.6/site-packages/urllib3/connectionpool.py", line 850, in _validate_conn
    conn.connect()
  File "/usr/lib/python3.6/site-packages/urllib3/connection.py", line 326, in connect
    ssl_context=context)
  File "/usr/lib/python3.6/site-packages/urllib3/util/ssl_.py", line 329, in ssl_wrap_socket
    return context.wrap_socket(sock, server_hostname=server_hostname)
  File "/usr/lib/python3.6/ssl.py", line 407, in wrap_socket
    _context=self, _session=session)
  File "/usr/lib/python3.6/ssl.py", line 814, in __init__
    self.do_handshake()
  File "/usr/lib/python3.6/ssl.py", line 1068, in do_handshake
    self._sslobj.do_handshake()
  File "/usr/lib/python3.6/ssl.py", line 689, in do_handshake
    self._sslobj.do_handshake()
ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)

It appears that this is because the session object of the HTTPClient doesn't play nice when REQUESTS_CA_BUNDLE is set. This is apparently a known issue in requests, and it doesn't look like there's an ETA for a fix (they're pushing it off to v3.0.0):

psf/requests#3829

I can confirm this is the case by passing the verify argument to the get method:

>>> api.session.get('https://192.168.64.7:8443')
...
ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)
>>> api.session.get('https://192.168.64.7:8443', verify=api.session.verify)
<Response [200]>

This might be able to be worked around for now by adding the verify argument to kwargs in HTTPClient.get_kwargs. I'll investigate further and open a PR if that's the case

[jmaroeder]

Never mind, I see this is already fixed in master. If anyone else comes across this issue, you can work around it (at least temporarily) by installing pykube>=0.16a1.