Using Docker to Execute Offline Instances of CMSSW

Abstract

With the newer versions, Docker is getting more and more stable and comes up with new features. Porting CMSSW workflows into it could make it easier to reproduce the execution on machines without access to the framework or to make a frozen benchmark that will always execute correctly.

This report shows the main problems faced when generating the Docker container, the chosen solutions and some avoidable dead ends. In the end, the reader should be able to understand the main steps involved in achieving this objective.

The result of the work is an command-line tool developed in Python named Morpheus. generating containers of CMSSW workflows, allowing usage of external tools and some customization. By using of the CMSSW environment installed in the host machine, it can generate working containers for the desired workflows. All the code have been documented and it should be easy to be extended.