This change makes us always try to use the latest master builds of the intermediate images
for the --cache-from option in our docker build of the supervisor.
This prevents cache misses when we're rebasing a branch and a PR has been merged that modifies a component that we're not modifying
in the current branch.
For example:
Branch 1 modifies the base image. Branch 2 only modifies the nodejs code. Branch 1 gets merged before Branch 2, so in our Branch2 PR we
rebase from master - in the next build for Branch 2, we'll have a cache miss on the base image, unless we're using the last master for caching.
Change-Type: patch
Signed-off-by: Pablo Carranza Velez <pablo@resin.io>
Otherwise the step where we build them doesn't reuse what was built when building the supervisor,
because we're explicitly setting `--cache-from` options.
We also push the images as soon as they're built.
Signed-off-by: Pablo Carranza Velez <pablo@resin.io>
Also, avoid building the dind builder twice, and try to get a reusable docker instance.
Change-Type: patch
Signed-off-by: Pablo Carranza Velez <pablo@resin.io>
