kubectl: export pod logs to file

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Say you have your kubernetes setup going and want to use kubectl to save/export the logs of a pod to a file.


In its simplest form, use kubectl logs:

kubectl logs -n my-namespace my-pod-name-xyz > my-pod-name.log


But there are other parameters, such as --since-time if you only want the logs after a certain point in time:

kubectl logs -n my-namespace my-pod-name-xyz --since-time=2020-12-02T00:00:00Z > my-pod-name-since-2020-12-02.log


That’s it.



More?

For a list of all possible options, use

kubectl logs -h

Current version outputs:

Print the logs for a container in a pod or specified resource. If the pod has only one container, the container name is
optional.

Examples:
  # Return snapshot logs from pod nginx with only one container
  kubectl logs nginx

  # Return snapshot logs from pod nginx with multi containers
  kubectl logs nginx --all-containers=true

  # Return snapshot logs from all containers in pods defined by label app=nginx
  kubectl logs -lapp=nginx --all-containers=true

  # Return snapshot of previous terminated ruby container logs from pod web-1
  kubectl logs -p -c ruby web-1

  # Begin streaming the logs of the ruby container in pod web-1
  kubectl logs -f -c ruby web-1

  # Begin streaming the logs from all containers in pods defined by label app=nginx
  kubectl logs -f -lapp=nginx --all-containers=true

  # Display only the most recent 20 lines of output in pod nginx
  kubectl logs --tail=20 nginx

  # Show all logs from pod nginx written in the last hour
  kubectl logs --since=1h nginx

  # Show logs from a kubelet with an expired serving certificate
  kubectl logs --insecure-skip-tls-verify-backend nginx

  # Return snapshot logs from first container of a job named hello
  kubectl logs job/hello

  # Return snapshot logs from container nginx-1 of a deployment named nginx
  kubectl logs deployment/nginx -c nginx-1

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.
      --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='': Only return logs after a specific date (RFC3339). Defaults to all logs. Only one of since-time /
since may be used.
      --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

Usage:
  kubectl logs [-f] [-p] (POD | TYPE/NAME) [-c CONTAINER] [options]

Use "kubectl options" for a list of global command-line options (applies to all commands).

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