Self installing service

self-installing-service.sh

#!/bin/bash -e
SERVICE_NAME="self-installing-service"
SERVICE_DESCRIPTION="A self installing service bash script"

SELF_FILE=$(readlink -f $0)
SELF_DIR=$(dirname $SELF_FILE)
SELF_FILENAME=$(basename $SELF_FILE)
SERVICE_CONFIG="/etc/systemd/system/${SERVICE_NAME}.service"
SERVICE_FILENAME=$(basename $SERVICE_CONFIG)

function daemon () {
  while true; do
    echo "I am a service..."
    sleep 5
  done
}

function install () {
  echo "Installing ${SERVICE_NAME}..."
  cat <<EOL | sudo tee $SERVICE_CONFIG > /dev/null
[Unit]
Description=${SERVICE_DESCRIPTION}
After=network.target

[Service]
ExecStart=${SELF_FILE} daemon
WorkingDirectory=${SELF_DIR}
User=${USER}
Restart=always
KillSignal=SIGINT
SyslogIdentifier=${SERVICE_NAME}

[Install]
WantedBy=multi-user.target
EOL
  sudo systemctl daemon-reload
  sudo systemctl enable $SERVICE_FILENAME
  start
}

function start () {
  echo "Starting ${SERVICE_NAME}..."
  sudo systemctl start $SERVICE_FILENAME
}

function restart () {
  echo "Restarting ${SERVICE_NAME}..."
  sudo systemctl restart $SERVICE_FILENAME
}

function stop () {
  echo "Stopping ${SERVICE_NAME}..."
  sudo systemctl stop $SERVICE_FILENAME  
}

function uninstall () {
  echo "Uninstalling ${SERVICE_NAME}..."
  sudo systemctl stop $SERVICE_FILENAME
  sudo systemctl disable $SERVICE_FILENAME
  sudo rm $SERVICE_CONFIG
  sudo systemctl daemon-reload
}

function logs () {
  journalctl -u $SERVICE_FILENAME $1
}

function usage () {
  echo "Usage: $SELF_FILENAME {install|start|restart|stop|uninstall|logs [-f]}"
}

action=$1

case $action in
  daemon)
    daemon
    ;;

  install)
    install
    ;;

  start)
    start
    ;;

  restart)
    restart
    ;;

  stop)
    stop
    ;;

  uninstall)
    uninstall
    ;;

  logs)
    logs $2
    ;;

  *)
    echo "Usage: $SELF_FILENAME {install|start|restart|stop|uninstall|logs [-f]}"
    ;;
esac