Expose some variables in the environment

[antoine-morvan]

Hello,

I have some scripts that need to know their location to execute properly. The JUBE launcher allows to copy some files to a generated fodler hierarchy. However, when you run a script, there is no variable in the environment that allow to access such information. Having a variable like JUBE_WORKDIR_PATH would be nice.

Some ideas for other variables can be taken from other existing solutions (for instance from here https://www.jenkins.io/doc/book/pipeline/jenkinsfile/#using-environment-variables or here https://docs.gitlab.com/ee/ci/variables/predefined_variables.html ).

Also, in a similar way it's done in other CI engines, it might be helpful to simply know when we are actually running under JUBE, with a set variable like JUBE_HPC=true.

Best.