Currently I have a Kubernetes pod that is running a cron job. The cron job writes to a log file at /var/log/cronlog. However, when I type kubectl log my-pod-name, the contents of /var/log/cronlog is not included.
How do I make it so that the contents of /var/log/cronlog is included with the output of kubectl log my-pod-name?
I think you should write to stdout and stderr not to a file to be able to use kubectl log
you can append the container startup script to include the logs
something like run.sh && tail -f /var/log/cronlog
First why you don't create Jobs using a CronJob Controller?
I think you should take advantage of using Kubernetes and make use of Jobs if they are supposed to run instead of plain cronjob. This will consume less resources and you will quickly check if cronjob failed.
Also as it was already mentioned in previous answers, you need to send messages/logs to stdout
Here is an example of a CronJob that does send date and prints Hello from the Kubernetes cluster to stdout, and logs can be accessed by kubectl logs job/<JOB_NAME>
apiVersion: batch/v1beta1
kind: CronJob
metadata:
name: hello
namespace: default
spec:
schedule: "* * * * *" # run every minute
startingDeadlineSeconds: 10 # if a job hasn't starting in this many seconds, skip
concurrencyPolicy: Forbid # either allow|forbid|replace
successfulJobsHistoryLimit: 3 # how many completed jobs should be
jobTemplate:
spec:
template:
spec:
containers:
- name: hello
image: busybox
args:
- /bin/sh
- -c
- date; echo Hello from the Kubernetes cluster
restartPolicy: OnFailureI hope this provide a bit of overview for You.