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[kube-proxy/ipvs] Add flag to enable strict ARP #75295

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k8s-ci-robot merged 1 commit into from
Mar 20, 2019
Merged

[kube-proxy/ipvs] Add flag to enable strict ARP #75295

k8s-ci-robot merged 1 commit into from
Mar 20, 2019

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@lbernail
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@lbernail lbernail commented Mar 12, 2019 •
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What type of PR is this?
/kind bug

Not exactly a bug but a regression for some users which use CNI plugins not compatible with this change.

What this PR does / why we need it:
#70530 introduced a change to avoid answering ARP queries for addresses bound to kube-ipvs0 (this broke some setups). However some CNI plugins use unnumbered ptp links between containers and host and this change breaks ARP for them. This PR adds a flag to control this behavior. It's not enabled by default to avoid breaking existing setups when upgrading (not that if a user has run a version that configures the sysctls they will need to change it back, kube-proxy won't do it).

Which issue(s) this PR fixes:
Fixes #71555
Fixes #72779

Not for reviewers:
We discussed alternatives in both issues (see above) and this one seems the best trade-off:

  • does not require an arptable rule per service
  • does not break existing setups
  • add an option to address issues faced by some users

It's the first I'm adding a flag so I may have have missed something. I tried to find a flag name that was clear and not too long but we can change it of course.

Does this PR introduce a user-facing change?:

[IPVS] Introduces flag ipvs-strict-arp to configure stricter ARP sysctls, defaulting to false to preserve existing behaviors. This was enabled by default in 1.13.0, which impacted a few CNI plugins.

/sig network
/area ipvs
/assign @m1093782566

cc @kvaps

@k8s-ci-robot k8s-ci-robot added release-note Denotes a PR that will be considered when it comes time to generate release notes. kind/bug Categorizes issue or PR as related to a bug. sig/network Categorizes an issue or PR as relevant to SIG Network. area/ipvs size/M Denotes a PR that changes 30-99 lines, ignoring generated files. cncf-cla: yes Indicates the PR's author has signed the CNCF CLA. needs-priority Indicates a PR lacks a `priority/foo` label and requires one. labels Mar 12, 2019
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k8s-ci-robot commented Mar 12, 2019

Hi @lbernail. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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@k8s-ci-robot k8s-ci-robot added the needs-ok-to-test Indicates a PR that requires an org member to verify it is safe to test. label Mar 12, 2019
@k8s-ci-robot k8s-ci-robot requested review from Lion-Wei and bowei March 12, 2019 16:28
@k8s-ci-robot k8s-ci-robot added the kind/api-change Categorizes issue or PR as related to adding, removing, or otherwise changing an API label Mar 12, 2019
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This PR may require API review.

If so, when the changes are ready, complete the pre-review checklist and request an API review.

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m1093782566 commented Mar 13, 2019

/ok-to-test

/assign @thockin

for API review.

@k8s-ci-robot k8s-ci-robot added ok-to-test Indicates a non-member PR verified by an org member that is safe to test. and removed needs-ok-to-test Indicates a PR that requires an org member to verify it is safe to test. labels Mar 13, 2019
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lbernail commented Mar 13, 2019

/test pull-kubernetes-kubemark-e2e-gce-big

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I'll approve, but @m1093782566 holds LGTM

/approve

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k8s-ci-robot commented Mar 13, 2019

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: lbernail, thockin

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@k8s-ci-robot k8s-ci-robot added the approved Indicates a PR has been approved by an approver from all required OWNERS files. label Mar 13, 2019
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m1093782566 commented Mar 19, 2019

/lgtm

Thanks @lbernail for contributing IPVS 👍

@k8s-ci-robot k8s-ci-robot added the lgtm "Looks good to me", indicates that a PR is ready to be merged. label Mar 19, 2019
@k8s-ci-robot k8s-ci-robot merged commit 59140d6 into kubernetes:master Mar 20, 2019
This was referenced Mar 26, 2019
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k8s-ci-robot added a commit that referenced this pull request Apr 4, 2019
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Merge pull request #75720 from DataDog/automated-cherry-pick-of-#7529…
df0d33a 
…5-upstream-release-1.13

Automated cherry pick of #75295 upstream release 1.13
k8s-ci-robot added a commit that referenced this pull request Apr 30, 2019
@k8s-ci-robot
Merge pull request #75719 from DataDog/automated-cherry-pick-of-#7529…
c72a5b2 
…5-upstream-release-1.14

Automated cherry pick of #75295 upstream release 1.14
@lbernail lbernail mentioned this pull request May 13, 2019
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@imroc imroc mentioned this pull request Jul 9, 2019
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champtar added a commit to champtar/kubespray that referenced this pull request Sep 17, 2019
@champtar
kube-proxy/ipvs: allow to configure strict ARP
6d15a94 
strict ARP flag was added by
kubernetes/kubernetes#75295

It's disable by default to not break some CNI, including flannel
so we leave it off by default

We must enable it for MetalLB to work
metallb/metallb#153 (comment)
so fail MetalLB roles if it's not enabled
@kvaps kvaps mentioned this pull request Feb 19, 2020
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@lbernail lbernail mentioned this pull request Jul 17, 2020
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@thockin thockin thockin left review comments

@bowei bowei Awaiting requested review from bowei

@Lion-Wei Lion-Wei Awaiting requested review from Lion-Wei

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@thockin thockin

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approved Indicates a PR has been approved by an approver from all required OWNERS files. area/ipvs cncf-cla: yes Indicates the PR's author has signed the CNCF CLA. kind/api-change Categorizes issue or PR as related to adding, removing, or otherwise changing an API kind/bug Categorizes issue or PR as related to a bug. lgtm "Looks good to me", indicates that a PR is ready to be merged. needs-priority Indicates a PR lacks a `priority/foo` label and requires one. ok-to-test Indicates a non-member PR verified by an org member that is safe to test. release-note Denotes a PR that will be considered when it comes time to generate release notes. sig/network Categorizes an issue or PR as relevant to SIG Network. size/M Denotes a PR that changes 30-99 lines, ignoring generated files.

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Successfully merging this pull request may close these issues.

kube-proxy v1.13.0 and 1.13.1 brokes services with externalIPs kube-proxy/IPVS: arp_ignore and arp_announce break some CNI plugins

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@lbernail @k8s-ci-robot @fejta-bot @m1093782566 @thockin