hi, I want to know what's the usage of wait_zeppelin_is_up_for_ci function in zeppelin-daemon.sh？thanks

[Taotao.Li]

thanks a lot, I'm reading the source code of zeppelin, hope to contribute 
something to this awesome project.

here is the source code:

function wait_zeppelin_is_up_for_ci() {
  if [[ "${CI}" == "true" ]]; then
    local count=0;
    while [[ "${count}" -lt 30 ]]; do
      curl -v localhost:8080 2>&1 | grep '200 OK'
      if [[ $? -ne 0 ]]; then
        sleep 1
        continue
      else
        break
      fi
        let "count+=1"
    done
  fi
}

here is the time to execute this function:

function start() {
  local pid

  if [[ -f "${ZEPPELIN_PID}" ]]; then
    pid=$(cat ${ZEPPELIN_PID})
    if kill -0 ${pid} >/dev/null 2>&1; then
      echo "${ZEPPELIN_NAME} is already running"
      return 0;
    fi
  fi

  initialize_default_directories

  nohup nice -n $ZEPPELIN_NICENESS $ZEPPELIN_RUNNER $JAVA_OPTS -cp $CLASSPATH 
$ZEPPELIN_MAIN >> "${ZEPPELIN_OUTFILE}" 2>&1 < /dev/null &
  pid=$!
  if [[ -z "${pid}" ]]; then
    action_msg "${ZEPPELIN_NAME} start" "${SET_ERROR}"
    return 1;
  else
    action_msg "${ZEPPELIN_NAME} start" "${SET_OK}"
    echo ${pid} > ${ZEPPELIN_PID}
  fi

  wait_zeppelin_is_up_for_ci
  sleep 2
  check_if_process_is_alive
}


thanks a lot