https://wiki.znc.in/Running_ZNC_as_a_system_daemon#Create_the_init.d_Scripts
====== Installation ======

<code bash>agi znc</code>

On va créer un user pour znc :
<code bash>sudo useradd --create-home -d /var/lib/znc --system --shell /sbin/nologin --comment "Account to run ZNC daemon" --user-group znc
sudo -u znc /usr/bin/znc --datadir=/var/lib/znc --makeconf</code>

Ensure the config file in /var/lib/znc/config/znc.conf instructs ZNC to create a PID file:
<code bash>echo "PidFile = /var/run/znc/znc.pid" | sudo su - znc -s /bin/bash -c "tee -a /var/lib/znc/configs/znc.conf"</code>

Après avoir répondu aux questions pour la config, on va créer un daemon :
<code bash>nano /etc/init.d/znc</code>

<code bash znc.txt[enable_line_numbers=1, highlight_lines_extra="8,76,79,98", skin=sons-of-obsidian]>
#! /bin/sh
### BEGIN INIT INFO
# Provides:          znc
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: ZNC IRC bouncer
# Description:       ZNC is an IRC bouncer
### END INIT INFO
 
PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC="ZNC daemon"
NAME=znc
DAEMON=/usr/bin/$NAME
DATADIR=/var/lib/znc
DAEMON_ARGS="--datadir=$DATADIR"
PIDDIR=/var/run/znc
PIDFILE=$PIDDIR/$NAME.pid
SCRIPTNAME=/etc/init.d/$NAME
USER=znc
GROUP=znc
 
# Exit if the package is not installed
[ -x "$DAEMON" ] || exit 0
 
# Read configuration variable file if it is present
[ -r /etc/default/$NAME ] && . /etc/default/$NAME
 
# Load the VERBOSE setting and other rcS variables
. /lib/init/vars.sh
 
# Define LSB log_* functions.
# Depend on lsb-base (>= 3.2-14) to ensure that this file is present
# and status_of_proc is working.
. /lib/lsb/init-functions
 
#
# Function that starts the daemon/service
#
do_start()
{
    # Return
    #   0 if daemon has been started
    #   1 if daemon was already running
    #   2 if daemon could not be started
    if [ ! -d $PIDDIR ]
    then
        mkdir $PIDDIR
    fi
    chown $USER:$GROUP $PIDDIR
    start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON --test --chuid $USER > /dev/null || return 1
    start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON --chuid $USER -- $DAEMON_ARGS > /dev/null || return 2
}
 
#
# Function that stops the daemon/service
#
do_stop()
{
    # Return
    #   0 if daemon has been stopped
    #   1 if daemon was already stopped
    #   2 if daemon could not be stopped
    #   other if a failure occurred
    start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 --pidfile $PIDFILE --name $NAME --chuid $USER
    RETVAL="$?"
    [ "$RETVAL" = 2 ] && return 2
    # Wait for children to finish too if this is a daemon that forks
    # and if the daemon is only ever run from this initscript.
    # If the above conditions are not satisfied then add some other code
    # that waits for the process to drop all resources that could be
    # needed by services started subsequently.  A last resort is to
    # sleep for some time.
    start-stop-daemon --stop --quiet --oknodo --retry=0/30/KILL/5 --exec $DAEMON --chuid $USER
    [ "$?" = 2 ] && return 2
    # Many daemons don't delete their pidfiles when they exit.
    rm -f $PIDFILE
    return "$RETVAL"
}
 
#
# Function that sends a SIGHUP to the daemon/service
#
do_reload() {
    start-stop-daemon --stop --signal 1 --quiet --pidfile $PIDFILE --name $NAME --chuid $USER
    return 0
}
 
case "$1" in
  start)
    [ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME"
    do_start
    case "$?" in
        0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
        2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
    esac
    ;;
  stop)
    [ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
    do_stop
    case "$?" in
        0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
        2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
    esac
    ;;
  status)
    status_of_proc -p $PIDFILE "$DAEMON" "$NAME" && exit 0 || exit $?
    ;;
  reload)
    log_daemon_msg "Reloading $DESC" "$NAME"
    do_reload
    log_end_msg $?
    ;;
  restart)
    log_daemon_msg "Restarting $DESC" "$NAME"
    do_stop
    case "$?" in
      0|1)
        do_start
        case "$?" in
            0) log_end_msg 0 ;;
            1) log_end_msg 1 ;; # Old process is still running
            *) log_end_msg 1 ;; # Failed to start
        esac
        ;;
      *)
        # Failed to stop
        log_end_msg 1
        ;;
    esac
    ;;
  *)
    echo "Usage: $SCRIPTNAME {status|start|stop|reload|restart}" >&2
    exit 3
    ;;
esac
</code>

<code bash>sudo chmod 755 /etc/init.d/znc</code>

Insert the script into the boot sequence :
<code bash>sudo update-rc.d znc defaults    # For Debian systems</code>

Start the service :
<code bash>sudo service znc start</code>

Verify that the service is running :
<code bash>sudo service znc status</code>

====== Ajout du certificat SSL ======

On en a déjà un, donc il suffit de faire une copie sur le certificat ZNC :
# on fait un backup avant
cp /var/lib/znc/znc.pem /var/lib/znc/znc.pem.bak
cat /etc/letsencrypt/live/$TON_DNS/{privkey,cert,chain}.pem > /var/lib/znc/znc.pem

====== Lancement du daemon lors du boot ======

Create the systemd unit
<code bash>nano /etc/systemd/system/znc.service</code>
<code bash znc.service[enable_line_numbers=1, highlight_lines_extra="8,76,79,98", skin=sons-of-obsidian]>
[Unit]
Description=ZNC, an advanced IRC bouncer
After=network-online.target
 
[Service]
ExecStart=/usr/bin/znc -f --datadir=/var/lib/znc
User=znc
 
[Install]
WantedBy=multi-user.target
</code>

Start the systemd unit and enable it for running on boot

With system service run:
<code bash>sudo systemctl start znc.service
sudo systemctl enable znc.service</code>

« start » starts the service now and « enable » starts it on boot.