Right now, you can do:

dimage = docker.image("whatever/whatever:99")

This seems fine, until you try to spin up a container, where it throws an exception (that you can catch, which is great).

dimage.withRun() { /* do nothing; just attempt to spin up container */ }

The problem is that takes some time on a loaded server, because it spins up a container for no real reason.

I would like a "validate" method. If that verb is too "heavy" and implies too much, "exists" would be fine, e.g.:

dimage = docker.image("whatever/whatever:99")
if (dimage.exists()) {
  ...
}

Workaround:

image_id = sh (script: "docker images -q whatever/whatever:99", returnStdout: true).trim()
if (image_id.isEmpty()) throw new Exception("Image not found")