Wait for kubernetes job to complete on either failure/success using command line

Question

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/myjob
         


        

Answer 1

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=failed 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_pid

Finally, 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_code

Complete 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=failed 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_code