Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Disable DNSStubListener for Flatcar Linux #9160

Merged
merged 2 commits into from
Aug 18, 2022
Merged

Disable DNSStubListener for Flatcar Linux #9160

merged 2 commits into from
Aug 18, 2022

Conversation

HoKim98
Copy link
Contributor

@HoKim98 HoKim98 commented Aug 9, 2022

What type of PR is this?

/kind bug

What this PR does / why we need it:

There is a conflict between the host DNSStubListener and the CoreDNS deployed on Kubernetes in Flatcar Linux.

0.0.0.0:53: bind: address already in use

We can solve it by turning off the host DNSStubListener.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

Disabled DNSStubListener for Flatcar Linux

@k8s-ci-robot k8s-ci-robot added kind/bug Categorizes issue or PR as related to a bug. cncf-cla: yes Indicates the PR's author has signed the CNCF CLA. needs-ok-to-test Indicates a PR that requires an org member to verify it is safe to test. labels Aug 9, 2022
@k8s-ci-robot
Copy link
Contributor

Hi @kerryeon. Thanks for your PR.

I'm waiting for a kubernetes-sigs 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.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

@k8s-ci-robot k8s-ci-robot added the size/XS Denotes a PR that changes 0-9 lines, ignoring generated files. label Aug 9, 2022
cristicalin
cristicalin reviewed Aug 10, 2022
View reviewed changes
roles/kubernetes/preinstall/templates/resolved.conf.j2
@@ -10,4 +10,8 @@ Domains={{ ([ 'default.svc.' + dns_domain, 'svc.' + dns_domain ] + searchdomains
#MulticastDNS=no
DNSSEC=no
Cache=no-negative
{% if ansible_os_family in ["Flatcar", "Flatcar Container Linux by Kinvolk"] %}
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This looks ok to me but it may be a more general solution to deal with distributions running systemd-resolved; why limit it to just Flatcar?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

At least in my environment (Flatcar Linux) this inevitably became a problem.

I've been tracking this issue steadily until very recently, and found that it crashes when the `nodelocaldns' feature is enabled.

I don't think this works the same on other distributions (such as Ubuntu). The enable_nodelocaldns feature is already enabled by default, so I know that no other major distributions have reported problems with it.

Another peculiarity is that, at least in Flatcar Linux, the /etc/resolv.conf configuration file is not valid, and instead depends only on the systemd-resolved. However, there are several resolvconf stuffs that are specific to Flatcar Linux, but I still don't know why they exist.

Especially,

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Hmm, ok, lets go ahead with this change then and see if other deployments report this problem, I have a suspicion that ubuntu 22.04 may be affected as well bug since I'm not running that in production anywhere this is just a suspicion.

@k8s-ci-robot k8s-ci-robot added the approved Indicates a PR has been approved by an approver from all required OWNERS files. label Aug 10, 2022
@cristicalin
Copy link
Contributor

/approve
/ok-to-test

@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 Aug 10, 2022
floryut
floryut approved these changes Aug 18, 2022
View reviewed changes
Copy link
Member

@floryut floryut left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

/lgtm
Agree on the not permanent fix but fine enough for now

@k8s-ci-robot k8s-ci-robot added the lgtm "Looks good to me", indicates that a PR is ready to be merged. label Aug 18, 2022
@k8s-ci-robot
Copy link
Contributor

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: cristicalin, floryut, kerryeon

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:
  • OWNERS [cristicalin,floryut]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

@k8s-ci-robot k8s-ci-robot merged commit be5fdab into kubernetes-sigs:master Aug 18, 2022
TinLe added a commit to TinLe/kubespray that referenced this pull request Aug 27, 2022
@TinLe
Merge remote-tracking branch 'upstream/master'
3fa0d59 
* upstream/master: (832 commits)
  add pre-commit hook to facilitate local testing (kubernetes-sigs#9158)
  cri-dockerd: add restart of docker.service (kubernetes-sigs#9205)
  do not run etcd role in scale.yml playbook when etcd installed by kubeadm (kubernetes-sigs#9210)
  optimize the format of evictionHard in kubelet-config.yaml template (kubernetes-sigs#9204)
  Update vars.md (kubernetes-sigs#9172)
  fix one bug in docs/nodes (kubernetes-sigs#9203)
  Fix containerd (<1.7) configuration for insecure registries (kubernetes-sigs#9207)
  🌱 Enable cri-dockerd service (kubernetes-sigs#9201)
  Update vsphere-csi.md (kubernetes-sigs#9170)
  9035: Make Cilium rolling-restart delay/timeout configurable (kubernetes-sigs#9176)
  [kubernetes] Add hashes for 1.24.4, 1.22.13, 1.23.10 and make v1.24.4 default (kubernetes-sigs#9191)
  Add 'avoid-buggy-ips' support of MetalLB (kubernetes-sigs#9166)
  Add the option to enable default Pod Security Configuration (kubernetes-sigs#9017)
  Add 'flush ip6tables' task in reset role (kubernetes-sigs#9168)
  add list nodes rules to cilium-operator clusterrole (kubernetes-sigs#9178)
  docs(kube-vip): fix broken links (kubernetes-sigs#9165)
  Disable DNSStubListener for Flatcar Linux (kubernetes-sigs#9160)
  Subnet setup order fix & Number of master nodes syntax fix (kubernetes-sigs#9159)
  Fix CSI drivers issues on Azure (kubernetes-sigs#9153)
  [calico] calico rr supports multiple groups (kubernetes-sigs#9134)
  ...
@floryut floryut mentioned this pull request Sep 19, 2022
Closed
@HoKim98 HoKim98 mentioned this pull request Sep 28, 2022
Closed
@cosandr cosandr mentioned this pull request Mar 9, 2023
Merged
nolimitkun pushed a commit to nolimitkun/kubespray that referenced this pull request Mar 19, 2023
@HoKim98 @nolimitkun
Disable DNSStubListener for Flatcar Linux (kubernetes-sigs#9160)
3b1ee76 
* Disable DNSStubListener for Flatcar Linux

* Fix missing "Flatcar" condition of os_family
LuckySB pushed a commit to southbridgeio/kubespray that referenced this pull request Jul 2, 2023
@HoKim98 @LuckySB
Disable DNSStubListener for Flatcar Linux (kubernetes-sigs#9160)
4340e01 
* Disable DNSStubListener for Flatcar Linux

* Fix missing "Flatcar" condition of os_family
LuckySB pushed a commit to southbridgeio/kubespray that referenced this pull request Jul 7, 2023
@HoKim98 @LuckySB
Disable DNSStubListener for Flatcar Linux (kubernetes-sigs#9160)
4e78d9a 
* Disable DNSStubListener for Flatcar Linux

* Fix missing "Flatcar" condition of os_family
@dustymabe dustymabe mentioned this pull request Sep 25, 2023
Open
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Reviewers

@cristicalin cristicalin cristicalin left review comments

@floryut floryut floryut approved these changes

@bozzo bozzo Awaiting requested review from bozzo

@oomichi oomichi Awaiting requested review from oomichi

Assignees

@floryut floryut

Labels
approved Indicates a PR has been approved by an approver from all required OWNERS files. cncf-cla: yes Indicates the PR's author has signed the CNCF CLA. 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. ok-to-test Indicates a non-member PR verified by an org member that is safe to test. size/XS Denotes a PR that changes 0-9 lines, ignoring generated files.
Projects
None yet
Milestone
No milestone
Development

Successfully merging this pull request may close these issues.
4 participants
@HoKim98 @k8s-ci-robot @cristicalin @floryut