First, take a look at the logs of the current container:
$ kubectl logs ${POD_NAME} ${CONTAINER_NAME}
If your container has previously crashed, you can access the previous container’s crash log with:
$ kubectl logs --previous ${POD_NAME} ${CONTAINER_NAME}
Alternately, you can run commands inside that container with exec:
$ kubectl exec ${POD_NAME} -c ${CONTAINER_NAME} -- ${CMD} ${ARG1} ${ARG2} ... ${ARGN}