What is the best way to wait for kubernetes job to be complete? I noticed a lot of suggestions to use:
kubectl wait --for=condition=complete job/myjobbut i think that only works if the job is successful. if it fails, i have to do something like:
kubectl wait --for=condition=failure job/myjobis there a way to wait for both conditions using wait? if not, what is the best way to wait for a job to either succeed or fail?
Run the first wait condition as a subprocess and capture its PID. If the condition is met, this process will exit with an exit code of 0.
kubectl wait --for=condition=complete job/myjob &
completion_pid=$!Do the same for the failure wait condition. The trick here is to add && exit 1 so that the subprocess returns a non-zero exit code when the job fails.
kubectl wait --for=condition=failure job/myjob && exit 1 &
failure_pid=$!
Then use the Bash builtin wait -n $PID1 $PID2 to wait for one of the conditions to succeed. The command will capture the exit code of the first process to exit:
wait -n $completion_pid $failure_pidFinally, you can check the actual exit code of wait -n to see whether the job failed or not:
exit_code=$?
if (( $exit_code == 0 )); then
echo "Job completed"
else
echo "Job failed with exit code ${exit_code}, exiting..."
fi
exit $exit_codeComplete example:
# wait for completion as background process - capture PID
kubectl wait --for=condition=complete job/myjob &
completion_pid=$!
# wait for failure as background process - capture PID
kubectl wait --for=condition=failure job/myjob && exit 1 &
failure_pid=$!
# capture exit code of the first subprocess to exit
wait -n $completion_pid $failure_pid
# store exit code in variable
exit_code=$?
if (( $exit_code == 0 )); then
echo "Job completed"
else
echo "Job failed with exit code ${exit_code}, exiting..."
fi
exit $exit_codekubectl wait --for=condition=<condition name is waiting for a specific condition, so afaik it can not specify multiple conditions at the moment.
My workaround is using oc get --wait, --wait is closed the command if the target resource is updated. I will monitor status section of the job using oc get --wait until status is updated. Update of status section is meaning the Job is complete with some status conditions.
If the job complete successfully, then status.conditions.type is updated immediately as Complete. But if the job is failed then the job pod will be restarted automatically regardless restartPolicy is OnFailure or Never. But we can deem the job is Failed status if not to updated as Complete after first update.
Look the my test evidence as follows.
Job yaml for testing successful complete
apiVersion: batch/v1 kind: Job metadata: name: pi spec: parallelism: 1 completions: 1 template: metadata: name: pi spec: containers: - name: pi image: perl command: ["perl", "-wle", "exit 0"] restartPolicy: Never
It will show you Complete if it complete the job successfully.
oc get job/pi -o=jsonpath='{.status}' -w && oc get job/pi -o=jsonpath='{.status.conditions[*].type}' | grep -i -E 'failed|complete' || echo "Failed"
job.batch/pi created map[startTime:2019-03-09T12:30:16Z active:1]Complete
Job yaml for testing failed complete
apiVersion: batch/v1 kind: Job metadata: name: pi spec: parallelism: 1 completions: 1 template: metadata: name: pi spec: containers: - name: pi image: perl command: ["perl", "-wle", "exit 1"] restartPolicy: Never
It will show you Failed if the first job update is not Complete. Test if after delete the existing job resource.
job.batch "pi" deleted
oc get job/pi -o=jsonpath='{.status}' -w && oc get job/pi -o=jsonpath='{.status.conditions[*].type}' | grep -i -E 'failed|complete' || echo "Failed"
job.batch/pi created map[active:1 startTime:2019-03-09T12:31:05Z]Failed
I hope it help you. :)