In this case you assume that the image exists somewhere in the registry. Do you think we can add a build definition here?

I'd like to enable error and access logging to log files, but unfortunately it's not possible.

@mtojek I was keeping this for later because it brings up a few questions related to the spec. Right now the spec for the _dev/deploy folder only allows specific files and folders under it. It does not allow for having any arbitrary additional files or folders.

Adding a build definition to the Docker Compose file and a Dockerfile to go with it is not a problem. We can add the Dockerfile to the spec file referenced above. However, sometimes a Dockerfile may reference other files, e.g. configuration files that must be copied into the image while building it. How do we account for this nicely in the spec? The simplest way would be to set additionalContents: true. More involved but slightly stricter would be to allow a specific sub-folder under _dev/deploy for arbitrary files. Do you have any thoughts?

I'm afraid we have to enable this option (additionalContents: true) for whole deploy or defining a specific type of deploy: docker and then enable it. This way we are safe if we want to introduce another deployment model (terraform?)

One thing we could do is expect a specific folder name under _dev/deploy corresponding to a supported deployment model. So a package could have this:

_dev/
  deploy/
   variants.yml (optional)
    docker/
      docker-compose.yml    (required)
      Dockerfile   (optional)
      (other, optional files as needed via `additionalContents: true`)

or:

_dev/
  deploy/
    terraform/
      TBD

or:

_dev/
  deploy/
    SOME_NEW_MODEL/
      TBD

And further we can probably enforce in the spec (in the future) that there must be exactly one sub-folder under _dev/deploy since a package should only specify one deployment model.

WDYT?

I like this model, but let's first focus on the docker runtime as this is the only one we have :)

Spec is adjusted in elastic/package-spec#49. Will do the dependency updates dance shortly.