Quick and dirty. Provides the basics for starting, stopping, viewing/using console, and updating to latest Spigot.

TODO: Possibly run as a system service.

#! /bin/bash
set -o errexit

# Minecraft Server Management Script
# By tmad40blue - http://tmad40.blue/

# !!! EDIT THE VARIABLES BELOW TO MATCH YOUR SERVER'S INFO !!!
# !!! DO NOT EDIT ANY OTHER PART OF THIS SCRIPT !!!

SERVDIR="" # The complete directory path where your JAR file is - example: /home/minecraft/servers/

SERVNAME="" # What you want your server's process to be called - lower-case, no spaces please - example: mcserver

MAXRAM="" # How much RAM (in GB) you want to allocate to this Minecraft server - example: 4

JARFILE="" # The full name of your server JAR - example: minecraft_server.jar

USERNAME="" # The name of the user (hopefully you) who is running the server - example: tmad40blue

# !!! DO NOT EDIT BELOW THIS LINE !!!

STARTCMD="java -Dname=${SERVNAME} -d64 -server -Xms512M -Xmx${MAXRAM}G -XX:+UseG1GC -XX:MaxGCPauseMillis=50 -jar ${JARFILE}"

ME=`whoami`

# Functions
as_user() {
  if [ "$ME" = "$USERNAME" ] ; then
    bash -c "$1"
  else
    su - "$USERNAME" -c "$1"
  fi
}

is_running() {
  # echo "DEBUG: U: ${USERNAME} S: {$SERVNAME}"
  return `pgrep -u ${USERNAME} -f "$SERVNAME" > /dev/null`
}

server_start() {
  if is_running ; then
    echo -e "$(tput setaf 1)$(tput bold)ERROR: $(tput sgr 0)Server is already running!"
  else
    echo -e "$(tput dim) Starting $(tput setaf 3)$SERVNAME$(tput sgr 0)..."
    as_user "tmux new-session -d -s mcserver -n mcserver $STARTCMD"
    as_user "tmux send-keys -t mcserver Enter"
    sleep 3
    if is_running ; then
      echo -e "$(tput setaf 2)Server is now running.$(tput sgr 0)"
    else
      echo -e "$(tput setaf 1)$(tput bold)ERROR: $(tput sgr 0)Server did not start!"
    fi
  fi
}

server_stop() {
  if is_running ; then
    echo -e "$(tput dim)Saving $(tput setaf 3)$SERVNAME$(tput sgr 0)..."
    as_user "tmux send-keys -t mcserver "save-all" Enter"
    sleep 5
    echo -e "$(tput dim)Stopping $(tput setaf 3)$SERVNAME$(tput sgr 0)..."
    as_user "tmux send-keys -t mcserver "stop" Enter"
    counter=0
    while is_running ; do
      sleep 1
      let counter=counter+1
      if [ "${counter}" -gt "1" ]; then
        echo -e "$(tput dim)${counter}$(tput sgr 0)"
      fi
    done
    # as_user "tmux kill-session -t mcserver" &
    echo -e "$(tput setaf 2)Server stopped.$(tput sgr 0)"
  else
    echo -e "$(tput setaf 1)$(tput bold)ERROR: $(tput sgr 0)Server is not running!"
  fi
}

server_console() {
  echo -e "$(tput setaf 3)Opening server console..."
  echo -e "$(tput setaf 1)$(tput bold)$(tput blink)!!! PRESS $(tput setaf 5)Ctrl-B $(tput setaf 1)THEN $(tput setaf 5)D $(tput setaf 1)TO EXIT CONSOLE !!! $(tput sgr 0)"
  echo -e "\n \n \n"
  while true; do
    read -e -i "y" -p "Continue? $(tput dim)[$(tput setaf 2)y$(tput sgr 0)$(tput dim)/$(tput setaf 1)n$(tput sgr 0)$(tput dim)] $(tput sgr 0)" yn
    case $yn in
      [Yy]*)
        break
        ;;
      [Nn]*)
        echo -e "$(tput dim)Exiting. $(tput sgr 0)"; return
        ;;
      *)
        echo "Please answer 'y' or 'n'."
        ;;
    esac
  done
  as_user "tmux a -t mcserver"
}
server_update() {
  if is_running ; then
    echo -e "$(tput setaf 1)$(tput bold)ERROR: $(tput sgr 0)Cannot update server while it is still running!"
  else
    echo -e "$(tput setaf 3)Updating to latest Spigot...$(tput sgr 0)"
    echo -e "$(tput setaf 1)$(tput bold)$(tput blink)!!! THIS WILL TAKE A LONG TIME !!!$(tput sgr 0)"
    sleep 3
    cd $SERVDIR
    rm -rf .m2
    rm -rf _buildtools
    mkdir "_buildtools"
    cd "_buildtools"
    wget -O "BuildTools.jar" "https://hub.spigotmc.org/jenkins/job/BuildTools/lastSuccessfulBuild/artifact/target/BuildTools.jar"
    # git config --global --unset core.autocrlf
    sleep 2
    java -d64 -Xms512M -Xmx${MAXRAM}G -XX:+UseG1GC -XX:MaxGCPauseMillis=50 -jar BuildTools.jar
    echo -e "$(tput setaf 2)Update complete! $(tput sgr 0)Cleaning up..."
    cd $DIRECTORY
    cp _buildtools/spigot-*.jar ${SERVDIR}/spigot.jar
    rm -rf .m2
    rm -rf _buildtools
    tput clear
    echo "$(tput setaf 2)All done! $(tput sgr 0)The latest Spigot should now be in your server directory."
  fi
}
echo -e "\n \n \n"
echo -e "$(tput bold)$(tput smul)Minecraft Server Management Script$(tput rmul) $(tput sgr 0)"
echo -e "$(tput bold)Written by $(tput setaf 6)tmad40blue $(tput sgr 0) -- $(tput setaf 4)http://tmad40.blue/ $(tput sgr 0)"
echo -e "$(tput dim)Version 1.0 $(tput sgr 0)"
echo -e "\n \n \n"
sleep 1

# Command processing
case "$1" in
  start)
    server_start
    ;;
  stop)
    server_stop
    ;;
  update)
    server_update
    ;;
  console)
    server_console
    ;;
  restart)
    server_stop
    server_start
    ;;
  running)
    if is_running ; then
      echo -e "$(tput setaf 2)Server is running. $(tput sgr 0)"
    else
      echo -e "$(tput setaf 1)Server is not running. $(tput sgr 0)"
    fi
    ;;

  *)
    echo -e "Usage: $(tput setaf 2)$0 $(tput sgr 0)$(tput dim){start|stop|restart|console|running|update}$(tput sgr 0)"
    exit 1
    ;;
esac

exit 0