How to set up a CERN OpenStack instance with AFS and GRID access

Create a VM instace

• Use guide https://clouddocs.web.cern.ch/clouddocs/tutorial_using_a_browser/index.html
• Use image SLC6 CERN Server - x86_64
• I also tried CC 7 image but failed to connect with the user account

Log in as root using the keypair

• You may also want to setup ssh tunneling - see https://security.web.cern.ch/security/recommendations/en/ssh_tunneling.shtml

Install the packages for GRID to work

yum install wget 
yum-config-manager --add-repo http://linuxsoft.cern.ch/wlcg/wlcg-sl6.repo
wget http://linuxsoft.cern.ch/wlcg/RPM-GPG-KEY-wlcg -P /etc/pki/rpm-gpg
yum install wlcg-repo
yum install voms-clients
yum-config-manager --add-repo http://linuxsoft.cern.ch/egi/production/cas/1/current
wget http://repository.egi.eu/sw/production/cas/1/current/repo-files/egi-trustanchors.repo -O /etc/yum.repos.d/egi-trustanchors.repo
yum install CERN-CA-certs ca_CERN-GridCA ca_CERN-Root ca_CERN-Root-2
yum install wlcg-voms-lhcb

Test the setup

• Log in in with your CERN username and CERN password. The machine would take up to 1 hour to setup into this stage, be patient.
• Assuming you had GRID set up on lxplus, you can test the setup by running

voms-proxy-init -voms lhcb
SetupProject Bender
echo "ls()" | bender "root://xrootd-lhcb.cr.cnaf.infn.it//storage/gpfs_lhcb/lhcb/disk/LHCb/Collision15/TURBO.MDST/00047765/0000/00047765_00001241_1.turbo.mdst"

You should see Bender output with the event fields like this:

/Event/DAQ                                                         DataObject 
/Event/DAQ/RawEvent                                                LHCb::RawEvent 
/Event/DAQ/ODIN                                                    LHCb::ODIN 
/Event/Turbo                                                 
/Event/Rec                                                         DataObject 

Or, if something happens with this particular site, FAILURE in the Ipython section with IODataManager       ERROR Error: connectDataIO> Cannot connect to database in the log above.

Setup tmux and k5reath for running background tasks with AFS access

• yum install afs_tools tmux
• https://lhcb.github.io/analysis-essentials/shell/persistent-screen.html

-- NikitaKazeev - 2016-02-08