G. Pape
runit

Name

runsv - starts and monitors a service and optionally an appendant log service

Synopsis

runsv 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.

If the file service/down exists, runsv does not start ./run immediately. The control interface (see below) can be used to start the service 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 a redirected to read from the pipe.

runsv maintains status information in a binary format compatible to supervise(8) in service/supervise/status and service/log/supervise/status, and in a human-readable format in service/supervise/stat, service/log/supervise/stat, service/supervise/pid, service/log/supervise/pid.

Control

The named pipes service/supervise/control, and (optionally) service/log/supervise/control are provided to give commands to runsv. You can use svc(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. 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.
1
User-defined 1. If the service is running, send it a USR1 signal.
2
User-defined 2. If the service is running, send it a USR2 signal.
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 or e
Exit. If the service is running, send it a TERM 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.

For example, to send a TERM signal to /service/socklog-unix, either do # svc -t /service/socklog-unix
or
# echo -n t >/service/socklog-unix/supervise/control

If echo(1) on your systems does not provide the -n option, leave it out, runsv ignores unknown characters written to the control pipe. echo(1) usually blocks if no runsv process is running in the service directory.

Signals

If runsv receives a TERM signal, it acts as if the character x was written to the control pipe.

Exit Codes

runsv 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 Also

runsvctrl(8), runsvstat(8), runit(8), runit-init(8), runsvdir(8), runsvchdir(8), svlogd(8), svwaitdown(8), svwaitup(8), svc(8), supervise(8)

http://smarden.org/runit/
http://cr.yp.to/daemontools.html

Author

Gerrit Pape <pape@smarden.org>


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