[oxzi]

Extract our Go License Check action used in Icinga DB, Notifications, K8s, and the Go Library into a reusable action.

---

Successfully tested this in our downstream repos:

• GHA: Common Go License Action icingadb#1233
  https://github.com/Icinga/icingadb/actions/runs/41802940955/job/126484702753?pr=1233
• GHA: Common Go License Action icinga-notifications#603
  https://github.com/Icinga/icinga-notifications/actions/runs/41803761723/job/126485632755?pr=603
• GHA: Common Go License Action icinga-go-library#279
  https://github.com/Icinga/icinga-go-library/actions/runs/41803951777/job/126486250324?pr=279
• GHA: Common Go License Action icinga-kubernetes#290
  https://github.com/Icinga/icinga-kubernetes/actions/runs/41804352432/job/126487558208?pr=290

[julianbrost]

Hopping in with a quick question: you're leaving the list of allowed licenses within the individual projects and there's already some divergence there. We need a distinction whether our repo is MIT or GPL licensed, but say for all GPLv3+ repos, the list of allowed licenses should be identical. Have you considered specifying a target license as an input (i.e. all licenses used should be compatible with that) and selecting a preset of allowed licenses from that?

[oxzi]

Just in time 🙃

I thought about detecting the current license from the LICENSE file and selecting an allow list of accepted licenses, but then decided against adding it here - at least at the moment. Since IANAL, I am even unsure which licenses are compatible and our downstream repos are currently under three different licenses (where two, iirc, should be relicensed to GPLv3).

[julianbrost]

At least Icinga DB and Icinga Notifications both are GPL-2.0-only and already have diverging lists of allowed licenses in their checks. I doubt that's intentional in the sense that's necessary, but probably happened because after the list was duplicated, one repo added another compatible license. If that action took compatible_with: GPL-2.0-only (or similar) as an input and the list would be in this repo, all repos using it would automatically benefit of an extended list.

[oxzi]

Fair enough; I will create a follow up PR to generalize this :)