runsv(8)runsv(8)NAMErunsv - starts and monitors a service and optionally an appendant log
service
SYNOPSISrunsv service
DESCRIPTION
service must be a directory.
runsv switches to the directory service and starts ./run. If ./run
exits and ./finish exists, runsv starts ./finish. If ./finish doesn't
exist or ./finish exits, runsv restarts ./run.
If ./run or ./finish exit immediately, runsv waits a second before
starting ./finish or restarting ./run.
Two arguments are given to ./finish. The first one is ./run's exit
code, or -1 if ./run didn't exit normally. The second one is the least
significant byte of the exit status as determined by waitpid(2); for
instance it is 0 if ./run exited normally, and the signal number if
./run was terminated by a signal. If runsv cannot start ./run for some
reason, the exit code is 111 and the status is 0.
If the file service/down exists, runsv does not start ./run immedi‐
ately. The control interface (see below) can be used to start the ser‐
vice and to give other commands to runsv.
If the directory service/log exists, runsv creates a pipe, redirects
service/run's and service/finish's standard output to the pipe,
switches to the directory service/log and starts ./run (and ./finish)
exactly as described above for the service directory. The standard
input of the log service is redirected to read from the pipe.
runsv maintains status information in a binary format (compatible to
the daemontools' supervise program) in service/supervise/status and
service/log/supervise/status, and in a human-readable format in ser‐
vice/supervise/stat, service/log/supervise/stat, service/supervise/pid,
service/log/supervise/pid.
CONTROL
The named pipes service/supervise/control, and (optionally) ser‐
vice/log/supervise/control are provided to give commands to runsv. You
can use sv(8) to control the service or just write one of the following
characters to the named pipe:
u Up. If the service is not running, start it. If the service
stops, restart it.
d Down. If the service is running, send it a TERM signal, and
then a CONT signal. If ./run exits, start ./finish if it
exists. After it stops, do not restart service.
o Once. If the service is not running, start it. Do not restart
it if it stops.
p Pause. If the service is running, send it a STOP signal.
c Continue. If the service is running, send it a CONT signal.
h Hangup. If the service is running, send it a HUP signal.
a Alarm. If the service is running, send it a ALRM signal.
i Interrupt. If the service is running, send it a INT signal.
q Quit. If the service is running, send it a QUIT signal.
1 User-defined 1. If the service is running, send it a USR1 sig‐
nal.
2 User-defined 2. If the service is running, send it a USR2 sig‐
nal.
t Terminate. If the service is running, send it a TERM signal.
k Kill. If the service is running, send it a KILL signal.
x Exit. If the service is running, send it a TERM signal, and
then a CONT signal. Do not restart the service. If the service
is down, and no log service exists, runsv exits. If the service
is down and a log service exists, runsv closes the standard
input of the log service, and waits for it to terminate. If the
log service is down, runsv exits. This command is ignored if it
is given to service/log/supervise/control.
Example: to send a TERM signal to the socklog-unix service, either do
# sv term /var/servicesocklog-unix
or
# printf t >/var/servicesocklog-unix/supervise/control
printf(1) usually blocks if no runsv process is running in the service
directory.
CUSTOMIZE CONTROL
For each control character c sent to the control pipe, runsv first
checks if service/control/c exists and is executable. If so, it starts
service/control/c and waits for it to terminate, before interpreting
the command. If the program exits with return code 0, runsv refrains
from sending the service the corresponding signal. The command o is
always considered as command u. On command d first service/control/t
is checked, and then service/control/d. On command x first ser‐
vice/control/t is checked, and then service/control/x. The control of
the optional log service cannot be customized.
SIGNALS
If runsv receives a TERM signal, it acts as if the character x was
written to the control pipe.
EXIT CODESrunsv exits 111 on an error on startup or if another runsv is running
in service.
runsv exits 0 if it was told to exit.
SEE ALSOsv(8), chpst(8), svlogd(8), runit(8), runit-init(8), runsvdir(8),
runsvchdir(8), utmpset(8)
http://smarden.org/runit/
AUTHOR
Gerrit Pape <pape@smarden.org>
runsv(8)
