Configuration Example¶
This example /etc/finit.conf can also be split up in multiple .conf
files in /etc/finit.d. Available, but not yet enabled, services can
be placed in /etc/finit.d/available and enabled by an operator using
the initctl tool.
See the contrib/ directory on GitHub for examples, or take a peek at systems using Finit, like Infix OS and myLinux.
Tip
A block spans as many lines as it needs, so no continuation character is called for. For the full syntax, see the finit.conf(5) manual or the Configuration section.
# Fallback if /etc/hostname is missing
hostname = "default"
# Runlevel to start after bootstrap, 'S', default: 2
#runlevel = 2
# Global environment variables, be careful though with variables like
# PATH, SHELL, LOGNAME, etc.
#environment {
# PATH = "/usr/bin:/bin:/usr/sbin:/sbin"
#}
# Max file size for each log file: 100 kiB, rotate max 4 copies:
# log => log.1 => log.2.gz => log.3.gz => log.4.gz
log {
size = 100k
count = 4
}
# Services to be monitored and respawned as needed
service watchdog {
description = "System watchdog daemon"
runlevel = "S12345"
envfile = "-/etc/conf.d/watchdog"
command = "watchdog $WATCHDOG_OPTS $WATCHDOG_DEV"
}
service syslogd {
description = "System log daemon"
runlevel = "S12345"
envfile = "-/etc/conf.d/syslog"
command = "syslogd -n $SYSLOGD_OPTS"
}
service klogd {
description = "Kernel log daemon"
runlevel = "S12345"
conditions = { "pid/syslogd" }
envfile = "-/etc/conf.d/klogd"
command = "klogd -n $KLOGD_OPTS"
}
service lldpd {
description = "LLDP daemon (IEEE 802.1ab)"
runlevel = "2345"
envfile = "-/etc/conf.d/lldpd"
command = "lldpd -d $LLDPD_OPTS"
}
# The BusyBox ntpd does not use syslog when running in the foreground
# So we use this trick to redirect stdout/stderr to a log file. The
# log file is rotated with the above settings. The condition declares
# a dependency on a system default route (gateway) to be set. ntpd
# does not respect SIGHUP, so Finit restarts it on reload instead.
service ntpd {
description = "NTP daemon"
runlevel = "2345"
conditions = { "net/route/default" }
reload-signal = "none"
log { file = "/var/log/ntpd.log" }
command = "ntpd -n -l -I eth0"
}
# For multiple instances of the same service, add :ID to the block title.
service merecat:80 {
description = "Web server"
runlevel = "2345"
command = "merecat -n -p 80 /var/www"
}
service merecat:8080 {
description = "Old web server"
runlevel = "2345"
command = "merecat -n -p 8080 /var/www"
}
# Alternative method instead of below runparts, can also use /etc/rc.local
#sysv keyboard-setup {
# description = "Setting up preliminary keymap"
# runlevel = "S"
# command = "/etc/init.d/keyboard-setup"
#}
# Hidden from boot progress, using an empty description
#sysv acpid {
# description = ""
# runlevel = "S"
# command = "/etc/init.d/acpid"
#}
# Run start scripts from this directory
#runparts = "/etc/start.d"
# Virtual consoles run BusyBox getty, keep kernel default speed
tty tty1 {
runlevel = "12345"
command = "/sbin/getty -L 0 /dev/tty1 linux"
nowait = true
noclear = true
}
tty tty2 {
runlevel = "2345"
command = "/sbin/getty -L 0 /dev/tty2 linux"
nowait = true
noclear = true
}
tty tty3 {
runlevel = "2345"
command = "/sbin/getty -L 0 /dev/tty3 linux"
nowait = true
noclear = true
}
# Use built-in getty for serial port and USB serial
#tty ttyAMA0 { runlevel = "12345" device = "/dev/ttyAMA0" noclear = true nowait = true }
#tty ttyUSB0 { runlevel = "12345" device = "/dev/ttyUSB0" noclear = true }
# Just give me a shell, I need to debug this embedded system!
#tty console { runlevel = "12345" device = "@console" noclear = true nologin = true }
The service block, as well as task, run and others are described in
full in the Services Syntax section.
Here's a quick overview of some of the most common components needed to start a UNIX daemon:
service NAME { <-- Supervised program (daemon)
description = "Example daemon" <-- Optional description
runlevel = "2345" <-- Optional runlevels
conditions = { "net/route/default" } <-- Optional conditions
envfile = "-/etc/default/daemon" <-- Optional env. file
log { } <-- Redirect output to log
command = "daemon ARGS" <-- Path to daemon, and its arguments
}
Only command is required, which makes simple cases short while leaving
room for more advanced uses:
service sshd {
command = "/usr/sbin/sshd -D"
}
Dependencies are handled using conditions. One of the most common conditions is to wait for basic networking to become available:
service nginx {
description = "High performance HTTP server"
conditions = { "net/route/default" }
command = "nginx"
}
Here is another example where we instruct Finit to not start BusyBox
ntpd until syslogd has started properly. Finit waits for syslogd
to create its PID file, by default /var/run/syslogd.pid.
service ntpd {
runlevel = "2345"
conditions = { "pid/syslogd" }
reload-signal = "none"
log { }
command = "ntpd -n -N -p pool.ntp.org"
}
service syslogd {
description = "Syslog daemon"
runlevel = "S12345"
command = "syslogd -n"
}
Notice the empty log block, BusyBox ntpd uses stderr for logging
when run in the foreground. With it Finit redirects stdout +
stderr to the system log daemon using the command line logger(1)
tool.
A service, or task, can have multiple dependencies listed. Here we wait
for both syslogd to have started and basic networking to be up:
service ntpd {
runlevel = "2345"
conditions = { "pid/syslogd", "net/route/default" }
log { }
command = "ntpd -n -N -p pool.ntp.org"
}
If either condition fails, e.g. loss of networking, ntpd is stopped
and as soon as it comes back up again ntpd is restarted automatically.
Note
Make sure daemons do not fork and detach themselves from the controlling
TTY, usually an -n or -f flag, or -D as in the case of OpenSSH above.
If it detaches itself, Finit cannot monitor it and will instead try to
restart it.