Using EESSI + direnv to ship a workflow execution environment

This repository gives a trivial example of how one can use the direnv tool together with EESSI to ship the complete execution environment for a Nextflow pipeline (including Nextflow itself) with your repository.

Once EESSI and direnv are in place and configured, running the code is a matter of entering the repository directory and running the workflow:

./hello_plus_version.nf

Caveats

• You need to have EESSI and direnv available on the system. Soon this will be limited to just having EESSI on the system (once EESSI ships direnv).
  • The repository uses the .envrc file to allow direnv to configure the environment (which it gets from EESSI).
• You need to have direnv enabled for your shell (e.g., eval "$(direnv hook bash)" for bash). A helper script to install and configure direnv is available (but it is pretty invasive so is hidden)

  source .install_direnv.sh
  

• You need to whitelist the repository directory for direnv (direnv will also tell you this once you are inside the repository directory):

  direnv allow