spark-ec2 credentials using aws_security_token

[ja...@centrum.cz]

Hi,
 
I would like to ask if it is currently possible to use spark-ec2 script together with credentials that are consisting not only from: aws_access_key_id and aws_secret_access_key, but it also contains aws_security_token.
 
When I try to run the script I am getting following error message:
 
ERROR:boto:Caught exception reading instance data
Traceback (most recent call last):
  File "/Users/zikes/opensource/spark/ec2/lib/boto-2.34.0/boto/utils.py", line 210, in retry_url
    r = opener.open(req, timeout=timeout)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 404, in open
    response = self._open(req, data)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 422, in _open
    '_open', req)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 382, in _call_chain
    result = func(*args)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 1214, in http_open
    return self.do_open(httplib.HTTPConnection, req)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 1184, in do_open
    raise URLError(err)
URLError: <urlopen error [Errno 64] Host is down>
ERROR:boto:Unable to read instance data, giving up
No handler was ready to authenticate. 1 handlers were checked. ['QuerySignatureV2AuthHandler'] Check your credentials
 
Does anyone has some idea what can be possibly wrong? Is aws_security_token the problem?
I know that it seems more like a boto problem, but still I would like to ask if anybody has some experience with this?
 
My launch command is:
./spark-ec2 -k my_key -i my_key.pem --additional-tags "mytag:tag1,mytag2:tag2" --instance-profile-name "profile1" -s 1 launch test
 
Thank you in advance for any help.
Best regards,
 
Jan
 
Note:
I have also asked at http://stackoverflow.com/questions/31583513/spark-spark-ec2-credentials-using-aws-security-token?noredirect=1#comment51151822_31583513 without any success.