kubeadm uses and configures kube-log-runner

[system51]

What happened?

klog command line flags are deprecated starting with Kubernetes v1.23 and removed in Kubernetes v1.26，I hope to use kube-log-runner to configure log output to a specified file，I deploy using kubeadm

What did you expect to happen?

I deploy using kubeadm，I hope to use kube-log-runner to configure log output to a specified file。How should I edit the kube-apiserver.yaml file

/apps/k8s/bin/kube-log-runner -log-file=/apps/k8s/log/kube-apiserver.log --also-stdout=false /apps/k8s/bin/kube-apiserver $KUBE_APISERVER_OPTS

How can we reproduce it (as minimally and precisely as possible)?

Deploy kubernetes using kubeadm

Anything else we need to know?

No response

Kubernetes version

kubeadm version: &version.Info{Major:"1", Minor:"29", GitVersion:"v1.29.2", GitCommit:"4b8e819355d791d96b7e9d9efe4cbafae2311c88", GitTreeState:"clean", BuildDate:"2024-02-14T10:39:04Z", GoVersion:"go1.21.7", Compiler:"gc", Platform:"linux/amd64"}

Cloud provider

nothing

OS version

NAME="Rocky Linux"
VERSION="8.7 (Green Obsidian)"
ID="rocky"
ID_LIKE="rhel centos fedora"
VERSION_ID="8.7"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Rocky Linux 8.7 (Green Obsidian)"
ANSI_COLOR="0;32"
LOGO="fedora-logo-icon"
CPE_NAME="cpe:/o:rocky:rocky:8:GA"
HOME_URL="https://rockylinux.org/"
BUG_REPORT_URL="https://bugs.rockylinux.org/"
ROCKY_SUPPORT_PRODUCT="Rocky-Linux-8"
ROCKY_SUPPORT_PRODUCT_VERSION="8.7"
REDHAT_SUPPORT_PRODUCT="Rocky Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="8.7"

[root@k8s-master-01 manifests]# uname -rn
k8s-master-01 6.7.6-1.el8.elrepo.x86_64

Install tools

Container runtime (CRI) and version (if applicable)

Related plugins (CNI, CSI, ...) and versions (if applicable)

[neolit123]

https://github.com/kubernetes/component-base/tree/master/logs/kube-log-runner

/sig instrumentation

[neolit123]

/kind support

[logicalhan]

/triage accepted
/assign @serathius

[system51]

I have found the solution, but I have a question why not integrate kube-log-runner into the kubernetes base image, such as kube-apiserver, kube-controller-manager, etc. The following is the correct configuration

spec:
  containers:
  - command:
    - /apps/kube-log-runner
    - --log-file=/apps/k8s/log/kube-apiserver.log
    - --also-stdout=false
    - kube-apiserver
    - --advertise-address=10.168.137.26
    - --allow-privileged=true
    - --authorization-mode=Node,RBAC
    - --client-ca-file=/etc/kubernetes/pki/ca.crt
    - --enable-admission-plugins=NodeRestriction
……

    volumeMounts:
    - mountPath: /apps/kube-log-runner
      name: kube-log-runner
    - mountPath: /apps/k8s/log
      name: k8s-logs

  volumes:
  - hostPath:
      path: /root/kube-log-runner
      type: File
    name: kube-log-runner
  - hostPath:
      path: /var/log/kubernetes/kube-apiserver
      type: DirectoryOrCreate
    name: k8s-logs

[mengjiao-liu]

but I have a question why not integrate kube-log-runner into the kubernetes base image

In fact, the kubernetes base image already integrates the kube-log-runner binary.

The Kubernetes registry.k8s.io/build-image/go-runner image wraps the gcr.io/distroless/static image and provides kube-log-runner under its traditional name as /go-runner. It gets maintained in https://github.com/kubernetes/release/tree/master/images/build/go-runner.

see details for https://github.com/kubernetes/component-base/tree/master/logs/kube-log-runner#container-base-image

Maybe @pohly @dims know more context?

@system51 You can use the go-runner(i.e. kube-log-runner) command directly without having to mount it:

Here is the manifest:

spec:
  containers:
  - command:
    - /go-runner
    - --log-file=/var/log/kube-apiserver.log
    - --also-stdout=false
    - --redirect-stderr=true
    - kube-apiserver
    - --advertise-address=10.6.9.1
    - --allow-privileged=true
    - --authorization-mode=Node,RBAC
    - --client-ca-file=/etc/kubernetes/pki/ca.crt
    - --enable-admission-plugins=NodeRestriction

    - mountPath: /var/log/kube-apiserver.log
      name: logfile
      readOnly: false

  volumes:
  - hostPath:
      path: /var/log/kube-apiserver.log
      type: FileOrCreate
    name: logfile

[system51]

@mengjiao-liu Thank you very much for your solution, it works after I tried it。

[pohly]

Seems to be resolved? Reopen if not...

/close

[k8s-ci-robot]

@pohly: Closing this issue.

In response to this:

Seems to be resolved? Reopen if not...

/close

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