gistfile1.txt

1- to obtain credentials:

# curl -s https://rackspace_api_urlv2.0/tokens -X 'POST' -d '{"auth":{"passwordCredentials":{"username":"user_name", "password":"my_pass"}}}' -H "Content-Type: application/json" | python -m json.tool

2- adding credentials.txt

# vim /root/credentials.txt
[rackspace_cloud]
username = user_name
api_key = aws_key

3- export and execute
# export RAX_CREDS_FILE=/root/credentials.txt
# python rax.py --list
/usr/lib64/python2.6/site-packages/Crypto/Util/number.py:57: PowmInsecureWarning: Not using mpz_powm_sec.  You should rebuild using libgmp >= 5 to avoid timing attack vulnerability.
  _warn("Not using mpz_powm_sec.  You should rebuild using libgmp >= 5 to avoid timing attack vulnerability.", PowmInsecureWarning)
rax.py:201: DeprecationWarning: BaseException.message has been deprecated as of Python 2.6
  sys.stderr.write("%s: %s\n" % (e, e.message))
Incorrect/unauthorized credentials received: Incorrect/unauthorized credentials received

# whoami
root

# set | grep RAX
RAX_CREDS_FILE=/root/credentials.txt