Create a default ManagedOSVersionChannel for os2

[mudler]

Now that we have a basic mechanism to update ManagedOSVersion in a cluster, let's try to consume it and create a ManagedOSVersion for os2, for example a yaml file which can be applied on a cluster afterwards (part of our release artifacts).

At the end the user should be able to kubectl apply a YAML file which will keep them in sync by using ManagedOSVersionChannel with our github releases by re-using the ManagedOSVersion logic.

example:

api: "v1"
Kind: "ManagedOSVersionChannel"

spec:
   type: "Custom"
   options:  |  
       ....

IF something won't fit for our use-case, probably won't fit for anyone else, so this is an explorative card, to figure out what it takes to get there (e.g. if the custom or JSON type aren't enough, we can think one about git, etc.).

This card is also about to distribute someway this mechanism to the users, as this is user-facing. Includes creating Docs also on how to update to a ManagedOSVersion with a ManagedOS, and how to setup custom ManagedOSVersionChannel.

For instance, we can even have a github repository hosting .json files corresponding to available releases, and a custom syncer that wraps them up in ManagedOSVersions

• Report back data from github API rancher-sandbox/upgradechannel-discovery#6
• Add version suffix/prefix rancher-sandbox/upgradechannel-discovery#5
• Allow reporting pre-releases from github rancher-sandbox/upgradechannel-discovery#4
• Add git discovery type rancher-sandbox/upgradechannel-discovery#7
• various fixes and add e2e upgrades tests rancher-sandbox/rancheros-operator#28
• Generate default upgrade channel image file in releases #95

[mudler]

Blocked by #84

[mudler]

WIP in https://github.com/rancher-sandbox/upgradechannel-discovery. I'm creating a small github discoverer image that can be used inside ManagedOSVersionChannel specs to pull versions from github releases (it just takes the versions, no other fields, like metadata are considered).

Ideally should be enough as a base to at least display available versions and select them for upgrades, individual enhancements we can track separately

[mudler]

I'm trying to have a look at #86 while at this, as currently I'd need to test the whole process manually again. maybe I can find an automated shortcut (without registering nodes) that we can include in our CI with a couple of tests on it.

[mudler]

A new os2 release is available with the default managedosversionchannel resource shipped as part of releases. Instructions on how to use it are in the docs