Docker Shared Layer Cache: Does this work?

[jaredlockhart]

Testing

[jaredlockhart]

So it technically works insomuch as it pushes the layers to dockerhub and then locally when you build it'll discover and pull them in much more quickly than it would take to build them from scratch EXCEPT it does a tarball/export step every time that takes ~90s for our ~2gb dev image, regardless of whether the layers are already cached locally and haven't changed. So that pretty much negates the benefit of doing this. There's relevant tickets filed about this :

docker/buildx#626
docker/build-push-action#401

So we can revisit this in the future if that behaviour changes.

[jaredlockhart]

I did manage to get this working here #5944