In a recent(ish) release of flyctl v0.1.93, we added the ability to label your docker images with metadata pertaining to your image build. Adding labels to an image isn’t a particularly new feature; you can technically already do this by adding the LABEL KEY="VALUE" in your Dockerfile. However with this new(ish) release, we’re now giving you the ability to add a label via the --label flag in the cli attached to the fly deploy command. This is similar to how you would label images via docker cli.
fly deploy --label CHECKING=THISWORKS
We’ve also added labels as an added column to the image metadata that you see when running fly image show on an app.
We hope labels are helpful as a way to better organize your images and add context to a deploy. Let us know what you think!