#!/bin/bash
# jeremystartm's jobrunner

# Check for PID file
if [ -f "/tmp/jobrunner/jobrunner.pid" ]; then
 echo ":: Error: The jobrunner daemon is already running."
 echo "          If you think that this is an error, remove"
 echo "          \"/tmp/jobrunner/jobrunner.pid\"."
 exit 1
fi

# Logging functions
function log() {
 [[ -z "${JOBRUNNER_DISABLEOUTPUT}" ]] && echo "${*}"
 echo "${*}" >> "/tmp/jobrunner/jobrunner.log"
}
function logcmd() {
 log ":: Execute: ${*}"
 ${*} &>> "/tmp/jobrunner/jobrunner.log"
}

# Set default timeout
[[ -z "${JOBRUNNER_TIMEOUT}" ]] && export "JOBRUNNER_TIMEOUT=0.1s"

# Create runtime directory
if [ -a "/tmp/jobrunner/" ] && [ ! -d "/tmp/jobrunner/" ]; then
 echo ":: Error: \"/tmp/jobrunner/\" is not a directory, aborting."
else
 echo ":: Creating runtime directory"
 mkdir -p "/tmp/jobrunner/"
 
 echo -n "" > /tmp/jobrunner/jobrunner.log
 rm -rf /tmp/jobrunner/jobrunner.cmd
fi

# Write PID file
log ":: Writing PID"
echo "$$" > "/tmp/jobrunner/jobrunner.pid"

log ":: Started jobrunner daemon"

# Enter loop
while true; do
 # Create jobrunner runtime directory if missing
 if [ ! -d "/tmp/jobrunner/" ]; then
  logcmd mkdir -p "/tmp/jobrunner/"
  echo "$$" > "/tmp/jobrunner/jobrunner.pid"
 fi
 
 if [ -f "/tmp/jobrunner/jobrunner.cmd" ]; then
  log ":: Executing command"
  
  # Read command file
  JOBRUNNER_COMMAND="$(cat "/tmp/jobrunner/jobrunner.cmd")"
  logcmd rm -rf "/tmp/jobrunner/jobrunner.cmd"
  
  # Check if contains exit action
  if [ "${JOBRUNNER_COMMAND}" == "EXIT" ]; then
   log ":: Exiting, as requested"
   logcmd rm -rf "/tmp/jobrunner/"
   exit 0
  fi
  
  # Execute command in subprocess
  echo ":: Execute: ${JOBRUNNER_COMMAND}" &>> /tmp/jobrunner/jobrunner.log
  ( ${JOBRUNNER_COMMAND} ) &>> /tmp/jobrunner/jobrunner.log &
 fi
 
 # Sleep specified amount
 sleep "${JOBRUNNER_TIMEOUT}"
done