workflows: automatically bump Cilium version to latest stable when releasing

[nbusseneau]

Follow-up to discussion in Jun 2 community meeting:

cilium install should default to installing the latest stable version of cilium/cilium, but we don't want to use the quay.io/cilium/cilium:stable because we need to have CLI versions pinning the Cilium version.

Proposed solution: have the release workflow automatically find which is the latest stable version and then patch it in the CLI (see #261 for example of which files to update).

This way we don't have to worry about managing versions: the CLI is always automatically pinned to the latest available stable Cilium version.

[kaworu]

... automatically find which is the latest stable version

AFAIK this is not possible to do automatically at the moment. This information is simply not available. At the moment, the latest stable version is v1.9.8 but helm install will install v1.10.0.

In Hubble, we have a stable.txt file in the master branch which contain the latest stable version.

[rolinh]

At the moment, the latest stable version is v1.9.8 but helm install will install v1.10.0.

I'm confused. v1.10.0 is the latest stable version, not v1.9.8 🤔

[pchaigno]

In Hubble, we have a stable.txt file in the master branch which contain the latest stable version.

Let's just add the same in cilium/cilium.

[kaworu]

I'm confused. v1.10.0 is the latest stable version, not v1.9.8 thinking

@rolinh correct thank you, I was confused by the v1.10.0 release note which can be interpreted as "v1.9.7 is still the stable release".

[rolinh]

cilium/cilium#16453 was merged which means that there's now a stable.txt file at the root of cilium's git repo master branch that always points to the latest stable release.