access logs in cron jobs kubernetes

I guess you know that the pod is kept around as you have successfulJobsHistoryLimit: 3. Presumably your point is that your logging is going logged to a file and not stdout and so you don't see it with kubectl logs. If so maybe you could also log to stdout or put something into the job to log the content of the file at the end, for example in a PreStop hook.

Cronjob runs pod according to the spec.schedule. After completing the task the pod's status will be set as completed, but the cronjob controller doesn't delete the pod after completing. And the log file content still there in the pod's container filesystem. So you need to do:

# here  you can get the pod_name from the stdout of the cmd `kubectl get pods`
$ kubectl logs -f -n default <pod_name>