如何查看K8s 集群pod log

$ oc get pods -n openshift-marketplace
NAME                                    READY   STATUS      RESTARTS      AGE
marketplace-operator-6f865d6bcf-j57n6   1/1     Running     2 (70m ago)   85m

$ oc logs marketplace-operator-6f865d6bcf-j57n6 -n openshift-marketplace
time="2024-03-01T06:18:17Z" level=info msg="Go Version: go1.19.13 X:strictfipsruntime"
time="2024-03-01T06:18:17Z" level=info msg="Go OS/Arch: linux/amd64"
...

$ oc logs --help
Print the logs for a resource.

 Supported resources are builds, build configs (bc), deployment configs (dc), and pods. When a pod is specified and has
more than one container, the container name should be specified via -c. When a build config or deployment config is
specified, you can view the logs for a particular version of it via --version.

 If your pod is failing to start, you may need to use the --previous option to see the logs of the last attempt.

Examples:
  # Start streaming the logs of the most recent build of the openldap build config
  oc logs -f bc/openldap
  
  # Start streaming the logs of the latest deployment of the mysql deployment config
  oc logs -f dc/mysql
  
  # Get the logs of the first deployment for the mysql deployment config. Note that logs
  # from older deployments may not exist either because the deployment was successful
  # or due to deployment pruning or manual deletion of the deployment
  oc logs --version=1 dc/mysql
  
  # Return a snapshot of ruby-container logs from pod backend
  oc logs backend -c ruby-container
  
  # Start streaming of ruby-container logs from pod backend
  oc logs -f pod/backend -c ruby-container

Options:
    --all-containers=false:
  Get all containers' logs in the pod(s).

    -c, --container='':
  Print the logs of this container

    -f, --follow=false:
  Specify if the logs should be streamed.

    --ignore-errors=false:
  If watching / following pod logs, allow for any errors that occur to be non-fatal

    --insecure-skip-tls-verify-backend=false:
  Skip verifying the identity of the kubelet that logs are requested from.  In theory, an attacker could provide
  invalid log content back. You might want to use this if your kubelet serving certificates have expired.

    --limit-bytes=0:
  Maximum bytes of logs to return. Defaults to no limit.

    --max-log-requests=5:
  Specify maximum number of concurrent logs to follow when using by a selector. Defaults to 5.

    --pod-running-timeout=20s:
  The length of time (like 5s, 2m, or 3h, higher than zero) to wait until at least one pod is running

    --prefix=false:
  Prefix each log line with the log source (pod name and container name)

    -p, --previous=false:
  If true, print the logs for the previous instance of the container in a pod if it exists.

    -l, --selector='':
  Selector (label query) to filter on, supports '=', '==', and '!='.(e.g. -l key1=value1,key2=value2). Matching
  objects must satisfy all of the specified label constraints.

    --since=0s:
  Only return logs newer than a relative duration like 5s, 2m, or 3h. Defaults to all logs. Only one of
  since-time / since may be used.

    --since-time='':
  仅返回在指定日期 (RFC3339) 之后的日志。默认为所有日志。只能使用 since-time / since 之一。

    --tail=-1:
  Lines of recent log file to display. Defaults to -1 with no selector, showing all log lines otherwise 10, if a
  selector is provided.

    --timestamps=false:
  Include timestamps on each line in the log output

    --version=0:
  View the logs of a particular build or deployment by version if greater than zero

$ oc get pods marketplace-operator-6f865d6bcf-j57n6  -o wide -n openshift-marketplace
NAME                                    READY   STATUS    RESTARTS       AGE    IP            NODE                          NOMINATED NODE   READINESS GATES
marketplace-operator-6f865d6bcf-j57n6   1/1     Running   2 (107m ago)   122m   10.128.0.14   xxx-2mkn4-master-1   <none>           <none>

$ oc debug node/xxx-2mkn4-master-1 
Temporary namespace openshift-debug-bcr2j is created for debugging node...
Starting pod/weinliu-1310-2mkn4-master-1-debug-7mcd9 ...
To use host binaries, run `chroot /host`
Pod IP: 10.0.0.5
If you don't see a command prompt, try pressing enter.
sh-4.4# chroot /host
sh-5.1# 

sh-5.1# cat /var/log/pods/openshift-marketplace_marketplace-operator-6f865d6bcf-j57n6_a471f288-df08-4c3e-9ddb-072daf300a56/marketplace-operator/
1.log  2.log 
sh-5.1# cat /var/log/pods/openshift-marketplace_marketplace-operator-6f865d6bcf-j57n6_a471f288-df08-4c3e-9ddb-072daf300a56/marketplace-operator/1.log 
2024-03-01T06:12:48.400484292+00:00 stderr F time="2024-03-01T06:12:48Z" level=info msg="Go Version: go1.19.13 X:strictfipsruntime"
2024-03-01T06:12:48.400484292+00:00 stderr F time="2024-03-01T06:12:48Z" level=info msg="Go OS/Arch: linux/amd64"
...

$ oc adm must-gather --help
Launch a pod to gather debugging information.

 This command will launch a pod in a temporary namespace on your cluster that gathers debugging information and then
downloads the gathered information.

Examples:
  # Gather information using the default plug-in image and command, writing into ./must-gather.local.<rand>
  oc adm must-gather
  
  # Gather information with a specific local folder to copy to
  oc adm must-gather --dest-dir=/local/directory
  
  # Gather audit information
  oc adm must-gather -- /usr/bin/gather_audit_logs
  
  # Gather information using multiple plug-in images
  oc adm must-gather --image=quay.io/kubevirt/must-gather --image=quay.io/openshift/origin-must-gather
  
  # Gather information using a specific image stream plug-in
  oc adm must-gather --image-stream=openshift/must-gather:latest
  
  # Gather information using a specific image, command, and pod directory
  oc adm must-gather --image=my/image:tag --source-dir=/pod/directory -- myspecial-command.sh

Options:
    --dest-dir='':
  Set a specific directory on the local machine to write gathered data to.

    --host-network=false:
  Run must-gather pods as hostNetwork: true - relevant if a specific command and image needs to capture
  host-level data

    --image=[]:
  Specify a must-gather plugin image to run. If not specified, OpenShift's default must-gather image will be
  used.

    --image-stream=[]:
  Specify an image stream (namespace/name:tag) containing a must-gather plugin image to run.

    --node-name='':
  Set a specific node to use - by default a random master will be used

    --node-selector='':
  Set a specific node selector to use - only relevant when specifying a command and image which needs to capture
  data on a set of cluster nodes simultaneously

    --run-namespace='':
  An existing privileged namespace where must-gather pods should run. If not specified a temporary namespace
  will be generated.

    --source-dir='/must-gather/':
  Set the specific directory on the pod copy the gathered data from.

    --timeout='10m':
  The length of time to gather data, like 5s, 2m, or 3h, higher than zero. Defaults to 10 minutes.

    --volume-percentage=30:
  Specify maximum percentage of must-gather pod's allocated volume that can be used. If this limit is exceeded,
  must-gather will stop gathering, but still copy gathered data. Defaults to 30%!