Watch mode / `build --watch`

[felipecrs]

Since Buildkit knows exactly which files in the system are required for the build, a --watch mode, that would rebuild an image automatically in case one of the files depended by it changes would come very in handy when developing docker images locally, or especially when testing them.

When called with --watch, buildx would NOT exit upon creation of the image, but instead would wait until the user exits with Ctrl+C.

Additionally, a bake --watch would be even better.

[sprat]

I agree, a bake --watch would be awesome!

[Azhovan]

/assign ✋🏻