[FR] check if an updated version of the image is available

[snqk]

I propose a new check to check if a new version of the image is available.

k8s_image_availability_exporter_<TYPE>_update_available

Thoughts?

[zuzzas]

How would you define a "new image"? Using Docker Registry API semantics.

[Stonedge]

The only way i could see that could be achieved is probably comparing tag...

I see 2 option here ....

1. generic regex that would cover most common case...
2. add annotation/label/config for custom tag format per image / deployment

Option1 generic regex:
^((?:version|v)?(?P<tagmajor>[0-9]{1,127})(?:[.\-_]?)?((?P<tagminor>[0-9]{1,127}))?(?:[.\-_]?)?((?P<tagpatch>[0-9]{1,127}))?(.*)?)$

covered version tag format:
1.2.3
v1.2
version1_2_4
ver-2.4-3
1.2.3-codename
1_2_3

so using something like when comparing available tag vs current tag:

Patch Available when tagmajor are equal, tagminor are equal, new tagpatch is greater
Minor Available when tagmajor are equal, new tagminor is greater
Major Available when new tagmajor is greater

Option 2:

would require a little more thinking ... but could be like a regex that return a number ... and if the previous returned number is lower than the current.... or regex than split tag in major minor patch format like option 1...

[snqk]

Semantic Versioning libraries also exist that can do this.

[nabokihms]

This is a nice-to-have feature, yet still, the goal of the exporter is to highlight the problematic workloads that are already running in the cluster. Predicting future versions sounds like a duty of a fancy gitops tool like argocd.

Anyway, I'm good if someone wants to implement this feature under a flag.