📖 Add KubeVirt instructions to tilt.md

[johananl]

What this PR does / why we need it:

This PR adds instructions for local development using KubeVirt as an alternative to CAPD.

This is useful in cases where CAPD can't be used for whatever reason, with one example being developing Ignition-related features (since Ignition runs in early boot and therefore can't be containerized easily).

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged): None

/area devtools

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[sbueringer]

Is there someone who is familiar with KubeVirt that could do a first review?

[nunnatsa]

Hi @johananl

Thanks for this PR. As far as I can see, this is based on the KubeVirt sections in the quickstart guide.

I just opened a PR to update it, as it didn't work for me now (I was working when I wrote it...). Maybe you want to take a look?

#11734

[fabriziopandini]

Thanks for writing this down.
It will be great if we can do a further step and re-use the existig scrpt for creating kind + registry as well as create a new script for automating most of the steps described in this doc

[fabriziopandini]

./hack/kind-install-for-capd.sh already creates a kind cluster with a registry, the only thing it does not support is to disable CNI.

Have you considered to improve ./hack/kind-install-for-capd.sh so we can have a consistent UX (re-use the same registry which persist across test runs, avoid ctlptl + related config file)

[johananl]

I liked the fact that ctlptl creates and destroys stuff reliably but I'm not attached to it in any way. I'm happy to improve this script. While at it I'll see if we can clean up things better since this script seems to leave a dangling registry container.

[fabriziopandini]

Can we keep image registry handling as it is given that it is orthogonal to this PR?

I don't remember exact details, but it was intentional to leave the registry around.
Probably something about avoiding to reload images e.g. in case you are testing on a fixed tag name, but I don't have time to look this up ATM

[johananl]

I've added ./hack/kind-install-for-kubevirt.sh that's based on the existing CAPD script. I like this more than the instructions (not sure why I haven't thought about this in the first place).

I'll update the Markdown file soon.

[fabriziopandini]

TBH I think we should have a scrpt to install CNI + MetalLB + KubeVirt, something like ./hack/kind-install-for-kubevirt.sh (that re-uses the existing script for the first part)