feat(services): support ipMode Proxy for LoadBalancer ingresses

[1fabi0]

This implements support for KEP-1860. When a LoadBalancer ingress has ipMode set to 'Proxy', kube-router will skip adding the IP to the local IPVS table and will not hijack the traffic. If ipMode is 'VIP' or unset, the current behavior is maintained.

Fixes #2014

[1fabi0]

I missed to stash a file after I changed it. I am going to correct that

[aauren]

@1fabi0 Thanks for the contribution. It would be nice to be compliant with KEP-1860 and it looks like it wouldn't take too much to get there. From that point of view this PR looks pretty straight forward.

However, it looks like we've changed underneath you so that your PR is no longer merge-able. Additionally, it looks like your work doesn't yet pass our linting and testing.

If you could rebase your work on the current master branch, and then run make in the project and clean up the linting / testing errors, that should be good enough for us to actually review this as a next step. I've tagged @catherinetcai to see if she has time to take a look once those steps are satisfied.

[1fabi0]

@aauren Thank you for the feedback! Since I don’t normally work with Go, I'm still getting used to the tooling. I missed the formatting step initially, which is why I did a couple of force pushes to fix it, I hope that’s alright.

Also, make is showing me the following error: kube-router_test.go:53: docs/user-guide.md 'command line options' section does not match 'kube-router --help'. I haven't made any changes related to the command-line options, so I assume this is unrelated to my PR. Let me know if this is a blocker or if I need to do anything about it.

Thanks
Fabian

[catherinetcai]

Hey @1fabi0, sorry for the delay. These changes look good to go. Great job!

I wasn't able to replicate the issue that came up for you when you ran make. Everything runs as expected if I pull your branch.

I also built and ran your branch in a Kind cluster running both MetalLB (LBs with IP mode VIP) + cloud-provider-kind (LBs with IP mode proxy) and validated that kube-router skips adding the IP for IP mode proxy LBs.