Hi! 

I'm follow this guide for plugin: [https://cloud.google.com/solutions/using-jenkins-for-distributed-builds-on-compute-engine

We have some automation for creating new google images with packer.

We use packer json template parameter: "image_name": "<static-prefix>-timestamp".

But we still need choose "Image name" from the list manually. 

Could you please to add regex form for gce plugin "Image name" parameter?
We can use pattern "^<some-prefix>-.*" and get the latest google image for slaves every time without manual operations.