Linkerd2: Windows node scheduling

[grampelberg]

What problem are you trying to solve?

As of today, the proxy does not run on windows nodes. Unfortunately, injection will still happen and the pod will just not run.

How should the problem be solved?

• Update inject to be aware of windows pods and skip injection on them.
• Update check to warn if there are windows nodes in the cluster.

Open questions

• Are there any ways we can surface that a pod is failing because of the proxy in a clear way?
• Should we recommend taints in the documentation?

[vaniisgh]

Hey!

If this issue is still relevant, I'd like to have a go at it :)
thanks

[grampelberg]

AFAIK it is still relevant!

[grampelberg]

We need to be adding the scheduling label as well so that proxies aren't scheduled to windows nodes in mixed clusters.

[grampelberg]

@alpeb did we ever land the change for the proxy injector to fail injection requests when it can't?

[alpeb]

@grampelberg Nope, that still hasn't landed #4235

[vaniisgh]

Should this issue be tackled only after that one has been merged since upon a cursory glance it seems to me that there are parts of code from that PR that could be extended to cover this one like the GetInjectFailReason could be made aware of windows pods and skip them while logging a WARNING?

I figure that check can still be updated to give warnings without causing any conflicts with that branch :)

adding scheduling labels sounds interesting, I don't know much about that I will certainly look into that as well if that's ok?

thanks :)

[grampelberg]

@vaniisgh they're kinda separate as this is just adding more reasons we can't inject a pod. So both this and the scheduling labels sounds like a great thing to work on!

[vaniisgh]

Oh! my bad... they looked similar to the untrained eye I guess :) Thanks for the clarification.
Sounds good.

[mayankshah1607]

@vaniisgh Let me know if you want to give #4235 a try. I'd be happy to help. :)

[vaniisgh]

@mayankshah1607 really! thank you so much! I just spent so long tracing the functions to find where I actually need to add code for this one, I think I have it figured. for #4235 you did quite a bit so that would be super helpful!
I also have a few very basic questions... would it be ok if I ping you on slack :)?

[mayankshah1607]

@vaniisgh Sure, feel free to do so!