Using singularity/apptainer to develop/run CMSSW

CMS now distribute cmssw-el{5,6,7,8,9} (available under /cvmfs/cms.cern.ch/common) helper scripts to setup cms OS env. The singularity/apptainer unpacked images used by these scripts are available under /cvmfs/unpacked.cern.ch/registry.hub.docker.com/ e.g. cmssw/elN:$(uname -m). List of available images is

• x86_64
  • cmssw/el9:x86_64
  • cmssw/el8:x86_64
  • cmssw/el7:x86_64
  • cmssw/el6:x86_64
  • cmssw/el5:x86_64
• aarch64
  • cmssw/el9:aarch64
  • cmssw/el8:aarch64
  • cmssw/el7:aarch64
• ppc64le
  • cmssw/el8:ppc64le
  • cmssw/el7:ppc64le

Setting up SLC5/SLC6/SLC7/EL8/EL9 CMS environment.

On lxplus, run cmssw-elN command to setup up the env e.g.

• To use SLC 5 environment:

lxplus> cmssw-el5
Singularity> cat /etc/redhat-release 
Scientific Linux CERN SLC release 5.11 (Boron)
Singularity> exit
lxplus>

or, to run a single command (in this example cat /etc/redhat-release to show the OS version), do

lxplus> cmssw-el5 -- cat /etc/redhat-release
Scientific Linux CERN SLC release 5.11 (Boron)

• To use SLC6/CentOS6 environment:

lxplus> cmssw-el6
Singularity> cat /etc/redhat-release 
CentOS release 6.10 (Final)
Singularity> exit
lxplus>

or, to run a single command (in this example cat /etc/redhat-release to show the OS version), do

lxplus> cmssw-el6 -- cat /etc/redhat-release
CentOS release 6.10 (Final)

• To use SLC7/CentOS7 environment:

lxplus> cmssw-el7
Singularity> cat /etc/redhat-release 
CentOS Linux release 7.8.2003 (Core)
Singularity> exit
lxplus>

or, to run a single command (in this example cat /etc/redhat-release to show the OS version), do

lxplus> cmssw-el7 -- cat /etc/redhat-release
CentOS Linux release 7.8.2003 (Core)

• To use EL8/9 environment:

lxplus> cmssw-el8 # OR cmssw-el9
Singularity> cat /etc/redhat-release
AlmaLinux release 8.5 (Arctic Sphynx)
Singularity> exit
lxplus>

or, to run a single command (in this example cat /etc/redhat-release to show the OS version), do

lxplus> cmssw-el9 -- cat /etc/redhat-release
AlmaLinux release 9.0 Beta (Emerald Puma)

Quick start

• Main page
• FAQ: CMSSW on Github
• CMS Naming, Coding, And Style Rules
• Proposing changes to CMSSW
• Setting up CMS environment using Singularity (new)
• Python virtual environment in CMSSW (new)
• CMSSW pull request approval workflow
• Collaborating with peers
• Working with CMSSW and UserCode
• Resolving conflicts & porting features
• How to use git through a proxy
• Building external packages (new)

Release Management

• CMSSW release notes
• Building a CMSSW release
• Integration Builds results
• Starting a new release cycle
• Forward ports
• Managing users and categories
• List categories and packages
• List of pending PRs
• Circle of pending PRs
• CMS-bot documentation
• CMS-bot commands

Infrastructure setup

• Monitoring
• Managing secrets with puppet
• Setting up builder machines
• Setting up builder machines [aarch64]
• Setting up builder machines [power8]
• Setting up cmsdev machines