Copilot-cli: Feature request: nonpersistent empty storage

[bpottier]

I have a scenario where I would like to run a sidecar that is responsible for pulling down and configuring some files. It could be useful to be able to define a shared volume for the task. Maybe something like the following:

volumes:
  source_volume: scratch
  path: /var/scratch

This is already possible with Fargate. See: https://docs.aws.amazon.com/AmazonECS/latest/developerguide/fargate-task-storage.html

Also, it might be useful to be able to mark a sidecar as not essential so that it can exit after doing its work. Maybe this is a bad approach though. I'm not sure.

[bvtujo]

Ohh, thanks os much for the feature request. This is a neat use case that we hadn't necessarily considered. It should be possible for us to do with our current volumes feature.

Once we enable passing in empty volumes, we can do the following:

storage:
  volumes:
    scratch:
      path: /var/scratch

sidecars:
  downloader:
    image: ${SIDECAR_IMAGE_URI}
    mount_points:
      - path: /var/scratch
        source_volume: scratch

```

[bpottier]

What about being able mark a sidecar as non-essential?

[bvtujo]

I've created a separate issue for us to track and prioritize the sidecar request over in #2066; please give it a thumbs up and we'll get it on our sprint planning!