Supose I have cronjob in Kubernetes that is scheduled each 30 minutes (10:00, 10:30, 11:00 etc.)
Supose also that due to resources job started at 10:05 instead of 10:00 or even 11:00 instead of 10:00
Is there an enviroment variable/option to know inside running pod at which time this pod was expected to be running?
Consider script that downloads everything from last hour - instead of 2 pods getting data from 10:00 to 11:00, I want option to utilize information of scheduled time;
anticipating questions - yes, I know i could do some queue/coding to avoid this problem, but I'm interested only in plain kubernetes possibilities.
If you do kubectl describe cj <name_of_cronjob> it will show you Last Schedule Time
Last Schedule Time: Tue, 07 May 2019 16:58:00 +0200
also You will see the events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal SuccessfulCreate 2m25s cronjob-controller Created job hello-1
Normal SawCompletedJob 2m15s cronjob-controller Saw completed job: hello-1
Normal SuccessfulCreate 85s cronjob-controller Created job hello-2
Normal SawCompletedJob 75s cronjob-controller Saw completed job: hello-2
Normal SuccessfulCreate 24s cronjob-controller Created job hello-3
Normal SawCompletedJob 14s cronjob-controller Saw completed job: hello-3You can add date as a command at the beginning on your CronJob it will tell you in logs when it started.
Yaml might look like this:
apiVersion: batch/v1beta1
kind: CronJob
metadata:
name: hello
spec:
schedule: "* * * * *"
jobTemplate:
spec:
template:
spec:
containers:
- name: hello
image: busybox
args:
- /bin/sh
- -c
- date; echo Hello from the Kubernetes cluster
restartPolicy: OnFailureYou can check for logs which will show you the data being executed.
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
hello-1-nrf5b 0/1 Completed 0 3m
hello-2-kk8t5 0/1 Completed 0 119s
hello-3-tpffz 0/1 Completed 0 59s
$ kubectl logs pods/hello-2-kk8t5
Tue May 7 14:58:09 UTC 2019
Hello from the Kubernetes clusterYou can see this example and other in the Kubernetes documentation Running Automated Tasks with a CronJob.