Unable to write pid file

[nandlab]

Linux distribution: Devuan GNU/Linux 4 (chimaera) x86_64
Init system: sysvinit

Mosquitto version: 2.0.11

/etc/mosquitto/mosquitto.conf:

# Place your local configuration in /etc/mosquitto/conf.d/
#
# A full description of the configuration file is at
# /usr/share/doc/mosquitto/examples/mosquitto.conf.example

pid_file /run/mosquitto/mosquitto.pid

persistence true
persistence_location /var/lib/mosquitto/

log_dest file /var/log/mosquitto/mosquitto.log

include_dir /etc/mosquitto/conf.d

When I type sudo mosquitto -c /etc/mosquitto/mosquitto.conf it says Unable to write pid file and does not start.

Apparently it does not have the required permissions to create the /run/mosquitto directory. If I create it manually it works, but the directory disappears after reboot.

[ptjm]

As of version 2.0, mosquitto drops down from root to the run-time user before the pid file is created. As far as I know, all you can do is create the pid file in advance and change ownership to mosquitto's run-time user before starting mosquitto.

[nandlab]

I have changed /etc/init.d/mosquitto as follows:

#!/bin/sh

### BEGIN INIT INFO
# Provides:		mosquitto
# Required-Start:	$remote_fs $syslog
# Required-Stop:	$remote_fs $syslog
# Default-Start:	2 3 4 5
# Default-Stop:		0 1 6
# Short-Description:	mosquitto MQTT v3.1 message broker
# Description:
#  This is a message broker that supports version 3.1 of the MQ Telemetry
#  Transport (MQTT) protocol.
#
#  MQTT provides a method of carrying out messaging using a publish/subscribe
#  model. It is lightweight, both in terms of bandwidth usage and ease of
#  implementation. This makes it particularly useful at the edge of the network
#  where a sensor or other simple device may be implemented using an arduino for
#  example.
### END INIT INFO

set -e

PIDDIR=/run/mosquitto
PIDFILE="${PIDDIR}/mosquitto.pid"
DAEMON=/usr/sbin/mosquitto

# /etc/init.d/mosquitto: start and stop the mosquitto MQTT message broker

test -x ${DAEMON} || exit 0

umask 022

. /lib/lsb/init-functions

# Are we running from init?
run_by_init() {
    ([ "$previous" ] && [ "$runlevel" ]) || [ "$runlevel" = S ]
}

export PATH="${PATH:+$PATH:}/usr/sbin:/sbin"

create_pid_dir() {
    mkdir -p "$PIDDIR"
    chown mosquitto: "$PIDDIR"
}

case "$1" in
  start)
	if init_is_upstart; then
	    exit 1
	fi
	create_pid_dir
	log_daemon_msg "Starting network daemon" "mosquitto"
	if start-stop-daemon -u mosquitto -c mosquitto --start --quiet --oknodo --background --pidfile ${PIDFILE} --exec ${DAEMON} -- -c /etc/mosquitto/mosquitto.conf ; then
	    log_end_msg 0
	else
	    log_end_msg 1
	fi
	;;
  stop)
	if init_is_upstart; then
	    exit 0
	fi
	log_daemon_msg "Stopping network daemon" "mosquitto"
	if start-stop-daemon -u mosquitto --stop --quiet --oknodo --pidfile ${PIDFILE}; then
	    log_end_msg 0
	    rm -f ${PIDFILE}
	else
	    log_end_msg 1
	fi
	;;


  reload|force-reload)
	if init_is_upstart; then
	    exit 1
	fi
	log_daemon_msg "Reloading network daemon configuration" "mosquitto"
        if start-stop-daemon -u mosquitto --stop --signal HUP --quiet --oknodo --pidfile $PIDFILE; then
            log_end_msg 0
        else
            log_end_msg 1
        fi
	;;

  restart)
	if init_is_upstart; then
	    exit 1
	fi
	log_daemon_msg "Restarting network daemon" "mosquitto"
	if start-stop-daemon -u mosquitto --stop --quiet --oknodo --retry 30 --pidfile ${PIDFILE}; then
	    rm -f ${PIDFILE}
	fi
	create_pid_dir
	if start-stop-daemon -c mosquitto -u mosquitto --start --quiet --oknodo --background --pidfile ${PIDFILE} --exec ${DAEMON} -- -c /etc/mosquitto/mosquitto.conf ; then
	    log_end_msg 0
	else
	    log_end_msg 1
	fi
	;;

  try-restart)
	if init_is_upstart; then
	    exit 1
	fi
	log_daemon_msg "Restarting Mosquitto message broker" "mosquitto"
	set +e
	start-stop-daemon -u mosquitto --stop --quiet --retry 30 --pidfile ${PIDFILE}
	RET="$?"
	set -e
	case $RET in
	    0)
		# old daemon stopped
		rm -f ${PIDFILE}
		if start-stop-daemon -c mosquitto -u mosquitto --start --quiet --oknodo --background --pidfile ${PIDFILE} --exec ${DAEMON} -- -c /etc/mosquitto/mosquitto.conf ; then
		    log_end_msg 0
		else
		    log_end_msg 1
		fi
		;;
	    1)
		# daemon not running
		log_progress_msg "(not running)"
		log_end_msg 0
		;;
	    *)
		# failed to stop
		log_progress_msg "(failed to stop)"
		log_end_msg 1
		;;
	esac
	;;

  status)
	if init_is_upstart; then
	    exit 1
	fi
	status_of_proc -p ${PIDFILE} ${DAEMON} mosquitto && exit 0 || exit $?
	;;

  *)
	log_action_msg "Usage: /etc/init.d/mosquitto {start|stop|reload|force-reload|restart|try-restart|status}"
	exit 1
esac

exit 0

Now it works.