DBS3 example to get file, lumi info for given dataset.

gistfile1.txt

#!/usr/bin/env python

import httplib
import urllib2, urllib
import sys, time, types
import json
import os

class HTTPSClientAuthHandler(urllib2.HTTPSHandler):
    """
    Simple HTTPS client authentication class based on provided
    key/ca information
    """
    def __init__(self, key=None, cert=None, debug=0):
        if  debug:
            urllib2.HTTPSHandler.__init__(self, debuglevel=1)
        else:
            urllib2.HTTPSHandler.__init__(self)
        self.key = key
        self.cert = cert

    def https_open(self, req):
        """Open request method"""
        #Rather than pass in a reference to a connection class, we pass in
        # a reference to a function which, for all intents and purposes,
        # will behave as a constructor
        return self.do_open(self.get_connection, req)

    def get_connection(self, host, timeout=300):
        """Connection method"""
        if  self.cert:
            return httplib.HTTPSConnection(host, key_file=self.key,
                                                cert_file=self.cert)
        return httplib.HTTPSConnection(host)

def file_lumi(dbs3_url, dataset, ckey, cert, debug=0):
    url = dbs3_url + '/blocks/?dataset=%s' % dataset
    print url

    req = urllib2.Request(url)
    headers = {'Accept': 'application/json;text/json'}
    if  headers:
        for key, val in headers.items():
            req.add_header(key, val)

    handler = HTTPSClientAuthHandler(ckey, cert, debug)
    opener  = urllib2.build_opener(handler)
    urllib2.install_opener(opener)

    data = urllib2.urlopen(req)
    blocks = json.load(data)
    ncalls = 1
    for row in blocks:
        blk = urllib.quote(row['block_name'])
        url = dbs3_url + '/filelumis?block_name=%s' % blk
        req = urllib2.Request(url)
        res = urllib2.urlopen(req)
        val = json.load(res)
        ncalls += 1
        print val
    print "dataset = %s" % dataset
    print "nblocks = %s" % len(blocks)
    print "ncalls  = %s" % ncalls

def main():
    "Series of DBS3 tests"
    ckey = os.path.join(os.environ['HOME'], '.globus/userkey.pem')
    cert = os.path.join(os.environ['HOME'], '.globus/usercert.pem')
    debug = 0
    dbs3_url = 'https://cmsweb.cern.ch/dbs/prod/global/DBSReader'
    dataset  = '/SingleMu/Run2012D-ZMu-PromptSkim-v1/RAW-RECO'
    dbs3_url = 'https://cmsweb-testbed.cern.ch/dbs/prod/global/DBSReader'
    dataset  = '/RelValMinBias/CMSSW_3_10_1-START310_V3-v1/GEN-SIM-RECO'
    dataset  = '/MinimumBias/Run2010B-Apr21ReReco-v1/RECO'

    # test file_lumi
    # ops example: find file, lumi where dataset=dataset
    time0 = time.time()
    file_lumi(dbs3_url, dataset, ckey, cert)
    print "Elapsed time:", (time.time()-time0)

if __name__ == '__main__':
    main()