Make docker entrypoint 'last_restore_file' runtime-variable

[ericsmalling]

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The hard coded path of for the last_restore_file in docker-entrypoint.sh does not work for users that need to use their own path for such files. Recommend using the same MEDUSA_TMP_DIR as used in restore.py for consistency.

Current:

last_restore_file=/var/lib/cassandra/.last-restore

Proposed replacement:

last_restore_file=${MEDUSA_TMP_DIR:-'/var/lib/cassandra'}/.last-restore

┆Issue is synchronized with this Jira Story by Unito
┆Issue Number: MED-5

[rzvoncek]

Hi @ericsmalling ! This looks like a great idea and the proposed replacement is neat. Any chance you could find a bit of time to convert this into a PR as well?

[ericsmalling]

Thanks, I'll tackle this ASAP

[ericsmalling]

Draft PR #787 open - I could use some pointers on how to add some tests around this though

[rzvoncek]

Hi. Thanks for the PR. For testing, the first step is to expose the variable via Dockerfile like I did here.

The next step would be to pass in a value when the Medusa container actually runs. In Medusa tests, we have the k8ssandra-e2e-tests where we do build Medusa and then have it run in k8ssandra-operator (just 2 tests). However, we can only specify an image tag through the medusa.spec.containerImage. I cannot think of a clean way of passing in the env var that's currently available.

We could also hardcode it at build time, but that feels like a worse solution.

Perhaps there's another way to make Medusa's entrypoint see the env var that I can't think of right now.