Services and daemons

Void uses the runit(8) supervision suite to run system services and daemons.

Services are enabled by simply linking them into the /var/service service directory.

# ln -s /etc/sv/<service name> /var/service/

To disable them again you just remove the link.

# rm /var/service/<service name>

Activated services can be controlled with the sv(8) command, following commands are available and can be used like sv <command> <services...>.

  • up to start, down to stop and once to start services once.
  • pause, cont, hup, alarm, interrupt, quit, 1, 2, term and kill to send the corresponding signal.
  • start, stop, reload and restart for LSB init compatibility.

See the sv(8) manual page for further information.

The status command can be used to retrieve the current status of one or more services. It accepts either service names or service directories, which makes it possible to use shell wildcards to retrieve the status for all activated services.

# sv status dhcpcd
run: /var/service/dhcpcd: (pid 659) 561392s
# sv status /var/service/*
run: /var/service/agetty-tty1: (pid 658) 561392s
run: /var/service/agetty-tty2: (pid 639) 561392s
run: /var/service/agetty-tty3: (pid 662) 561392s
run: /var/service/agetty-ttyS0: (pid 650) 561392s
run: /var/service/dhcpcd: (pid 659) 561392s
run: /var/service/nanoklogd: (pid 666) 561391s
run: /var/service/ntpd: (pid 665) 561391s; run: log: (pid 664) 561391s
run: /var/service/opensmtpd: (pid 661) 561392s
run: /var/service/socklog-unix: (pid 646) 561392s; run: log: (pid 645) 561392s
run: /var/service/sshd: (pid 674) 561391s
run: /var/service/udevd: (pid 660) 561392s
run: /var/service/uuidd: (pid 640) 561392s

Extra options can be passed to most services using a conf file in the service directory.

$ cat /etc/sv/sshd/run
#!/bin/sh
ssh-keygen -A >/dev/null 2>&1 # Will generate host keys if they don't already exist
[ -r conf ] && . ./conf
exec /usr/bin/sshd -D $OPTS
# echo 'OPTS="-p 2222"' >>/etc/sv/sshd/conf

Another example is the wpa_supplicant service which has other available variables.

# cat /etv/sv/wpa_supplicant/run
#!/bin/sh
[ -r ./conf ] && . ./conf
exec 2>&1
exec wpa_supplicant -c ${CONF_FILE:=/etc/wpa_supplicant/wpa_supplicant.conf} -i ${WPA_INTERFACE:=wlan0} ${OPTS:=-s}
# echo WPA_INTERFACE=wlp3s0 >>/etc/sv/wpa_supplicant/conf