Enable overwrites of default environment variables

[jonded94]

Should solve #873

[jacobtomlinson]

This is great many thanks! Would you mind adding a small test to verify this behaviour?

[jonded94]

Was sure you'd ask that 😄 I'm a bit unsure about that though.

Changing the Scheduler address from the default address will likely lead to that Cluster being broken in the CI test?
We could test though for a custom non-default Dask Worker name I guess? What do you think?

[jacobtomlinson]

We could test though for a custom non-default Dask Worker name I guess?

Yep that sounds like a great way to test it.

[jonded94]

@jacobtomlinson sorry for the delay, was busy with other things. PR should now be ready; I included some tests that will use the apparently previously unused "simpleworkergroup.yaml" for deploying an additional worker group that overrides the envvar "DASK_WORKER_NAME".
In the tests, it will check if the DASK_SCHEDULER still is intact.

[jacobtomlinson]

This looks great thanks!

[creste]

@jonded94 @jacobtomlinson - Does build_job_pod_spec also need to be updated to allow overwriting the default environment variables?

[jonded94]

Ah, sure, sorry, will do that too tomorrow. This one doesn't need a test though (overriding the scheduler address is anyways a bit weird to test).