Introduction to Docker: Setup

Docker installations

To install Docker on your machine follow the official instructions for Linux, Mac, or Windows.

If you are using Linux, then please also follow these post installation instructions.

To test your docker set up, run the following command:

docker run hello-world

Optional: Fetch docker images in advance

Once you’ve got docker up and running, do the following docker image pulls in advance to save waiting during the tutorial:

docker pull matthewfeickert/intro-to-docker
docker pull debian:buster-slim
docker pull python:2.7-slim
docker pull python:3.7-slim
docker pull rootproject/root:6.22.06-conda

Analysis Code

Later in this tutorial, you will be asked to work with a simple analysis that utilizes the CMS OpenData to search for Higgs to 2 tau leptons. The full analysis itself can be found here - and there is a dedicated set of training lessons (videos available). These are then used as input to the continuous integration training (videos available).

Though it is best if you work through these lessons, the key point is that we will assume you have two GitLab repos in your namespace :

• one containing code to skim the NanoAOD-like samples and convert them to histograms,
• one containing the code needed to do the final fit.

You can either do this yourself by following the aforementioned lessons, or if you’d like to start fresh you can use the following ‘starter’ repos that you can directly fork into your namespace and work directly from:

Skimming code: https://github.com/hsf-training/hsf-training-cms-analysis-snapshot

Fitting code: https://github.com/hsf-training/hsf-training-cms-analysis-snapshot-stats

A few things to keep in mind if starting from these ‘starter repos’:

• First and foremost: To fork these repos, open the GitLab project creation page and then select Import project -> Repository by URL. Please make sure you’ve forked the starter repos into your own namespace before cloning and making commits to them, otherwise you’ll run into permissions issues when you try to push your commits! Also remember to set the visibility level to Public.
• Regarding authentication with kinit:
  • If you are from CERN and use gitlab.cern.ch: Remember to add your CERN credentials as CI/CD variables to both repos for the kinit authentication in the .gitlab-ci.yml files to work. To do so, go to Settings -> CI/CD -> Variables and create two new variables:
    • CERN_USER should contain your CERN username
    • SERVICE_PASS should contain your password.
  • Else, you can remove the kinit line from .gitlab-ci.yml and use the public EOS datasets:
    • root://eospublic.cern.ch//eos/root-eos/HiggsTauTauReduced for the skimming repo.
    • root://eospublic.cern.ch//eos/opendata/cms/upload/apb2023/histograms.root for the fitting repo.
• For the fitting code repo, the fit_simple step in .gitlab-ci.yml expects to receive the file histograms.root produced by the skimming code. In case you haven’t had a chance to produce this file yet, it can be downloaded from here. In any case you can:
  • use the public EOS datasets mentioned above.
  • If you are from CERN, you can copy the downloaded file to your personal eos user space (root://eosuser.cern.ch//eos/user/[first_letter_of_username]/[username]).