Add dual stack support

[aojea]

Add dual stack support to KIND, it also needs to add dual-stack support to KINDNET
Depends on:

• Dual-Stack Integration with Kubeadm kubernetes/kubernetes#79033
• Phase 2 dualstack kubernetes/kubernetes#79386
• Dualstack support for kube-proxy iptables mode kubernetes/kubernetes#82462
• Kubeadm DualStack Support for List of Service IPs kubernetes/kubernetes#82473
• Allow multiple node cidr masks in kube-controller-manager kubernetes/kubernetes#79993
• Add e2e tests for ipv6 dual stack feature kubernetes/kubernetes#78801
• Dualstack downward api kubernetes/kubernetes#83123

New dependency for kindnet so we don't need annotations on the nodes:

• KEP-1664: Better Support for Dual-Stack Node Addresses kubernetes/enhancements#1665

[aojea]

cc: @vllry @khenidak @Arvinderpal @aramase

[Arvinderpal]

@aojea how are you handling DNS/NAT64 in kind?

[aojea]

@aojea how are you handling DNS/NAT64 in kind?

not handling it, should we? conformance tests are passing without it, just modified CoreDNS to work without contacting upstream servers

[Arvinderpal]

@aojea how are you handling DNS/NAT64 in kind?

not handling it, should we? conformance tests are passing without it, just modified CoreDNS to work without contacting upstream servers

Ok, but I suspect e2e networking tests like the following that test external connectivity from pods won't pass. In that case, we'll either need to use GUA addresses or some sort of NATing with ULA addresses.

[aojea]

Full e2e working is the next milestone, we were able to have conformance working yesterday ... One step at s time 😅

[aojea]

@BenTheElder we should revisit this now the 1.21 will have dualstack enabled by default

[BenTheElder]

generally lgtm. left comments.
in particular need to update the image, and I'm still dubious on the constant values.
we can iterate on the dependencies angle. I think we should cease importing k8s.io/* for trivial things, but we can handle that seperately.

[aojea]

/test pull-kind-conformance-parallel-dual-stack-ipv4-ipv6

generally lgtm. left comments.
in particular need to update the image, and I'm still dubious on the constant values.
we can iterate on the dependencies angle. I think we should cease importing k8s.io/* for trivial things, but we can handle that seperately.

modified constants and removed all the dependencies on k8s.io/utils

[aojea]

we need this for the dualstack CI job
kubernetes/test-infra#21537

once it is in kind I need to remember to change all the kubernetes jobs

[k8s-ci-robot]

@aojea: The following tests failed, say /retest to rerun all failed tests:

Test name	Commit	Details	Rerun command
pull-kind-conformance-parallel	863cfc0	link	/test pull-kind-conformance-parallel
pull-kind-conformance-parallel-1-14	1df6ecb	link	/test pull-kind-conformance-parallel-1-14

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[BenTheElder]

Antonio and I discussed this a bit and looked around quite a bit, and also discussed with the azure folks (since AKS supports this though without any high level config for it).

... There really isn't any standard way to refer to this. Kubernetes has a bunch of distinct concepts with different names surrounding dualstack and the broader networking community seems to use a variety of formats for referring to this.

https://kubernetes.io/docs/concepts/services-networking/dual-stack/

dual seems fine enough. I didn't intend for this to be a major sticking point, just a chance to find the least surprising / most obvious value for users before shipping the API, but that doesn't really seem to exist.

[BenTheElder]

/test pull-kind-conformance-parallel-dual-stack-ipv4-ipv6

[BenTheElder]

https://prow.k8s.io/view/gs/kubernetes-jenkins/pr-logs/pull/kubernetes-sigs_kind/692/pull-kind-conformance-parallel-dual-stack-ipv4-ipv6/1375693467413385216

🎉

[BenTheElder]

/lgtm
/approve
remaining nits can be addressed in follow up. past time to ship this.

for anyone following along, this has been helped along by a number of other PRs like #2043

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: aojea, BenTheElder

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[BenTheElder]

/hold cancel