Using Python 2.7.9 can cause SSL errors when connecting to REDCap

[nrejac]

Using Python 2.7.9 with GSM can cause SSL errors when connecting to REDCap. A sample stack trace:

Traceback (most recent call last):
  File "/Users/nrejack/code/nrejack/research-subject-mapper/v/bin/gsm", line 9, in 
    load_entry_point('rsm==0.10.2', 'console_scripts', 'gsm')()
  File "/Users/nrejack/code/nrejack/research-subject-mapper/v/lib/python2.7/site-packages/rsm-0.10.2-py2.7.egg/bin/generate_subject_map.py", line 55, in main
    response = rt.get_data_from_redcap(properties, logger)
  File "/Users/nrejack/code/nrejack/research-subject-mapper/v/lib/python2.7/site-packages/rsm-0.10.2-py2.7.egg/bin/utils/redcap_transactions.py", line 85, in get_data_from_redcap
    'Accept': 'text/plain'})
  File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/httplib.py", line 1001, in request
    self._send_request(method, url, body, headers)
  File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/httplib.py", line 1035, in _send_request
    self.endheaders(body)
  File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/httplib.py", line 997, in endheaders
    self._send_output(message_body)
  File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/httplib.py", line 850, in _send_output
    self.send(msg)
  File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/httplib.py", line 812, in send
    self.connect()
  File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/httplib.py", line 1212, in connect
    server_hostname=server_hostname)
  File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ssl.py", line 350, in wrap_socket
    _context=self)
  File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ssl.py", line 566, in __init__
    self.do_handshake()
  File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ssl.py", line 788, in do_handshake
    self._sslobj.do_handshake()
ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:581)

The suggested fix at this time is to use virtualenv with Python 2.7.6 or lower:

• Check which versions of Python are installed:

  ls /usr/bin/python*

• Check versions to find one that is suitable:

  /usr/bin/python2.7 --version 
  Python 2.7.6
  

• Create a virtualenv with that version:

  virtualenv v -p /usr/bin/python2.7

• Activate the virtualenv:

  source v/bin/activate