Proposal: Option to not push to registry on out

[akshaymankar]

Currently the resource always pushes to a registry on out, but we have a usecase where we don't really want to push the image anywhere, but package it in a bosh release. So, I would like to propose a flag called push_to_registry which will default to true, but can be toggled off.

/cc @vlad-stoian

[hephex]

I was looking into implementing this feature because I'm facing a similar problem, but out is supposed to create a new version of the resource and docker image resources are versioned using their digest string which is not available until the image gets pushed to the registry (see distribution/distribution#1662).

@akshaymankar any idea how to overcome this "limit"?

[jonahgeorge]

Has anyone come up with a temporary solution for this?

[vito]

There's not really any way to avoid pushing to the registry, since this resource is fundamentally about representing external state (as all resources are). The new pattern going forward is to use the builder task instead for image building and then the registry-image resource for image pushing.

These aren't quite official yet, since I'd like to wrap up concourse/rfcs#7 before 'blessing' the builder task, but we're using them in production and it's going pretty well.

Gonna close this issue out though since there won't be any changes made to the docker-image resource to support this, especially as we'll be deprecating it in favor of builder and registry-image. Thanks all!