Add --disable-coredns-log flag

[sugymt]

fixes #19757

Adds the --disable-coredns-log option to cluster startup. When enabled, this option removes the log plugin from the CoreDNS ConfigMap, preventing query logs from being output to the Pod logs.

---

before (default)

docker@minikube:~$ sudo ls -alh /var/lib/docker/containers/cae72a53aeead8e6cdc48846c46c3703eece0960e25e2119b40ce3453c9db585/cae72a53aeead8e6cdc48846c46c3703eece0960e25e2119b40ce
3453c9db585-json.log
-rw-r----- 1 root root 263K Jun 29 17:39 /var/lib/docker/containers/cae72a53aeead8e6cdc48846c46c3703eece0960e25e2119b40ce3453c9db585/cae72a53aeead8e6cdc48846c46c3703eece0960e25e2119b40ce3453c9db585-json.log
docker@minikube:~$ sudo head -n 10 /var/lib/docker/containers/cae72a53aeead8e6cdc48846c46c3703eece0960e25e2119b40ce3453c9db585/cae72a53aeead8e6cdc48846c46c3703eece0960e25e2119b4
0ce3453c9db585-json.log
{"log":".:53\n","stream":"stdout","time":"2025-06-29T17:37:16.911204731Z"}
{"log":"[INFO] plugin/reload: Running configuration SHA512 = 05e3eaddc414b2d71a69b2e2bc6f2681fc1f4d04bcdd3acc1a41457bb7db518208b95ddfc4c9fffedc59c25a8faf458be1af4915a4a3c0d6777cb7a346bc5d86\n","stream":"stdout","time":"2025-06-29T17:37:16.911254738Z"}
{"log":"CoreDNS-1.9.3\n","stream":"stdout","time":"2025-06-29T17:37:16.911263032Z"}
{"log":"linux/amd64, go1.18.2, 45b0a11\n","stream":"stdout","time":"2025-06-29T17:37:16.911265472Z"}
{"log":"[INFO] 127.0.0.1:50578 - 11501 \"HINFO IN 8305876105755474021.8070635482691607969. udp 57 false 512\" NXDOMAIN qr,rd,ra 132 0.006369538s\n","stream":"stdout","time":"2025-06-29T17:37:16.917272287Z"}
{"log":"[INFO] 10.244.0.2:60114 - 40402 \"A IN metadata.google.internal.elastic-system.svc.cluster.local. udp 86 false 1232\" NXDOMAIN qr,aa,rd 168 0.000292824s\n","stream":"stdout","time":"2025-06-29T17:37:30.657746089Z"}
{"log":"[INFO] 10.244.0.2:57182 - 21348 \"AAAA IN metadata.google.internal.elastic-system.svc.cluster.local. udp 86 false 1232\" NXDOMAIN qr,aa,rd 168 0.000354242s\n","stream":"stdout","time":"2025-06-29T17:37:30.657778154Z"}
{"log":"[INFO] 10.244.0.2:41830 - 48782 \"A IN metadata.google.internal.svc.cluster.local. udp 71 false 1232\" NXDOMAIN qr,aa,rd 153 0.000152372s\n","stream":"stdout","time":"2025-06-29T17:37:30.657780955Z"}
{"log":"[INFO] 10.244.0.2:40259 - 35747 \"AAAA IN metadata.google.internal.svc.cluster.local. udp 71 false 1232\" NXDOMAIN qr,aa,rd 153 0.00017997s\n","stream":"stdout","time":"2025-06-29T17:37:30.657783213Z"}
{"log":"[INFO] 10.244.0.2:33894 - 8445 \"A IN metadata.google.internal.cluster.local. udp 67 false 1232\" NXDOMAIN qr,aa,rd 149 0.000131425s\n","stream":"stdout","time":"2025-06-29T17:37:30.65825304Z"}

after (--disable-coredns-log)

$ kubectl logs -n kube-system -l k8s-app=kube-dns -f
.:53
[INFO] plugin/reload: Running configuration SHA512 = eff20e86b4fd2b9878e9c34205d7ba141ff41613cbdadb71e63d4a8be6caff7d1fbccef3edfe618baf8958049a58d98ae28ea781e3e7cdf1cc90820da8e01a6d
CoreDNS-1.9.3
linux/amd64, go1.18.2, 45b0a11

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: sugymt / name: Jun Sugimoto (2921937)

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[k8s-ci-robot]

Hi @sugymt. Thanks for your PR.

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[minikube-bot]

Can one of the admins verify this patch?

[nirs]

It will be easier to review if you squash this fix into the commit that added this change and force push.

[sugymt]

Okay, I've pushed it.

[medyagh]

/ok-to-test

[medyagh]

@sugymt I am curious what is the use case for this ? like what made you think about disabling it

[medyagh]

@sugymt would u plz put in the PR description "the logs of coredns" before/after this PR ?

[minikube-pr-bot]

kvm2 driver with docker runtime

+----------------+----------+---------------------+
|    COMMAND     | MINIKUBE | MINIKUBE (PR 20992) |
+----------------+----------+---------------------+
| minikube start | 52.3s    | 51.8s               |
| enable ingress | 16.0s    | 15.5s               |
+----------------+----------+---------------------+

Times for minikube start: 50.9s 52.6s 52.9s 52.5s 52.7s
Times for minikube (PR 20992) start: 51.9s 50.1s 54.5s 51.7s 51.0s

Times for minikube ingress: 16.1s 15.6s 16.1s 16.6s 15.6s
Times for minikube (PR 20992) ingress: 16.0s 15.1s 15.2s 15.6s 15.6s

docker driver with docker runtime

+----------------+----------+---------------------+
|    COMMAND     | MINIKUBE | MINIKUBE (PR 20992) |
+----------------+----------+---------------------+
| minikube start | 23.7s    | 25.4s               |
| enable ingress | 13.1s    | 13.5s               |
+----------------+----------+---------------------+

Times for minikube start: 22.5s 25.0s 23.3s 23.5s 24.0s
Times for minikube (PR 20992) start: 26.4s 23.7s 25.6s 25.1s 26.1s

Times for minikube ingress: 13.3s 13.3s 13.3s 13.3s 12.4s
Times for minikube (PR 20992) ingress: 13.9s 13.3s 14.0s 12.8s 13.3s

docker driver with containerd runtime

+----------------+----------+---------------------+
|    COMMAND     | MINIKUBE | MINIKUBE (PR 20992) |
+----------------+----------+---------------------+
| minikube start | 24.3s    | 23.9s               |
| enable ingress | 23.5s    | 26.0s               |
+----------------+----------+---------------------+

Times for minikube start: 24.8s 24.2s 26.1s 22.0s 24.7s
Times for minikube (PR 20992) start: 21.6s 22.1s 24.7s 26.7s 24.2s

Times for minikube ingress: 23.8s 23.3s 22.8s 23.8s 23.8s
Times for minikube (PR 20992) ingress: 22.8s 22.8s 22.8s 38.8s 22.8s

[sugymt]

@medyagh I've added a description. Could you please check the issue to see what led me to need this option?
#19757 (comment)

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This pull-request has been approved by: medyagh, sugymt

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