Feature Request: Base Image Lockfile

[gabrieljones]

Gradle has dependency version lockfiles.

I can declare my dependency versions as latest.release or [3,4[(any version 3.x, but not 4.x).

This offers flexibility at the cost of build reproducibility.

I can restore reproducibility by turning on dependency locking.

Once I've done all of that I get the best of both worlds.

Anytime I want to float to the latest version bounded by all of my dependency version ranges, I run ./gradlew dependencies --write-locks.

It is my desire to have a similar capability with jib base image declarations.

Whenever I run some command like --write-locks the sha of the latest version of my base image is discovered and then written to some kind of lock file. That sha is then used until such time as I run --write-locks again.

Of course all of this can be done manually. I've just gotten so used to the convenience afforded by the combination of gradle's version range declarations and its lockfile capability.