[Ubuntu 16.04] systemd service unit + monit task

[lord-alfred]

I made a small script/service to start and stop guerrillad after system startup (and a little more). This is my first experience, so I will be glad to hear comments. :)

#!/bin/sh
# kFreeBSD do not accept scripts as interpreters, using #!/bin/sh and sourcing.
if [ true != "$INIT_D_SCRIPT_SOURCED" ] ; then
    set "$0" "$@"; INIT_D_SCRIPT_SOURCED=true . /lib/init/init-d-script
fi
### BEGIN INIT INFO
# Provides:          guerrillad
# Required-Start:    $remote_fs $syslog $mysqld
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: mini smtp server
# Description:       mini smtp server guerrillad
### END INIT INFO

DESC="mini smtp server"
NAME="guerillad"

# some configuration variables (change to your!)
USER="guser"
CONFIG="/etc/guerrilla.conf.json"
DAEMON_FILE="/usr/local/bin/guerrillad"
DAEMON_LOG="/var/log/guerrilla/daemon.log"
PID_FILE="/var/run/guerrillad/guerrillad.pid"

PID_DIR=$(dirname $PID_FILE)

start_service() {
    # create directory (/var/run - is tmpfs, after reboot directory is removed)
    mkdir -p $PID_DIR
    chown -R $USER:$USER $PID_DIR

    # wait mysql start (fix "dial tcp 127.0.0.1:3306: connect: connection refused" in logs)
    sleep_iter=0
    sleep_max=30
    # mysql host and port (change if you use another!)
    until nc -z -v -w30 127.0.0.1 3306
    do
        if [ $sleep_iter -ge $sleep_max ]; then
            echo "sleep iter greater than max: $sleep_max"
            break
        fi

        echo "Waiting for database connection... iter: $sleep_iter"
        # wait for 1 seconds before check again
        sleep 1

        sleep_iter=$(expr $sleep_iter + 1)
    done

    # run guerrillad daemon
    sudo -i -u $USER $DAEMON_FILE -c $CONFIG serve >> $DAEMON_LOG 2>&1 &
}

stop_service() {
    PID=$(cat $PID_FILE)
    /bin/kill -TERM $PID
    RETVAL="$?"
    return "$RETVAL"
}

reload_config() {
    PID=$(cat $PID_FILE)
    /bin/kill -HUP $PID
    return 0
}

rotate_logs() {
    PID=$(cat $PID_FILE)
    /bin/kill -USR1 $PID
    return 0
}

case "$1" in
        start)
                echo "Starting $DESC"
                start_service
                echo "start exit code: $?"
                ;;
        stop)
                echo "Stopping $DESC"
                stop_service
                echo "stop exit code: $?"
                ;;
        restart)
                echo "Restarting $DESC"
                stop_service
                sleep 1
                start_service
                echo "restart exit code: $?"
                ;;
        reload)
                echo "Reloading $DESC configuration"
                reload_config
                echo "reloading configuration exit code: $?"
                ;;
        rotate)
                echo "Re-opening $DESC log files"
                rotate_logs
                echo "re-opening log files exit code: $?"
                ;;
        *)
                echo "Usage: $NAME {start|stop|restart|reload|rotate}" >&2
                exit 3
                ;;
esac

How to use it:

1. create file and put this script: sudo vim /etc/init.d/guerrillad
2. update services: update-rc.d guerrillad defaults
3. run service: systemctl start guerrillad
4. If you change /etc/init.d/guerrillad - reload service: systemctl daemon-reload

Use:

• start: /bin/systemctl start guerrillad
• stop: /bin/systemctl stop guerrillad
• restart: /bin/systemctl restart guerrillad
• reload (config): /bin/systemctl reload guerrillad
• status (with sudo for to view logs): sudo /bin/systemctl status guerrillad
• rotate (reopen log files): service guerrillad rotate (not systemctl rotate(!))

Bonus: monit task:

check process guerrillad with pidfile /var/run/guerrillad/guerrillad.pid
    start program = "/bin/systemctl start guerrillad"
    stop program = "/bin/systemctl stop guerrillad"
    if failed host 127.0.0.1 port 25 protocol smtp then restart
    if cpu > 60% for 2 cycles then alert
    if cpu > 80% for 5 cycles then restart
    if 5 restarts within 5 cycles then timeout
    group service

[flashmob]

Awesome! Do you allow me to add this to the wiki?

Have you tested the rotate and reload options? Sorry, out of time to try myself.

[lord-alfred]

Yes of course you can add this to the wiki! :)

I tested this options and they work (but I tested this only on Ubuntu 16.04)