G. Pape
runit
runsv - starts and monitors a service and optionally an appendant log
service
runsv service
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 is 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.
The named pipes
service/supervise/control, and (optionally) service/log/supervise/control
are provided to give commands to runsv. You can use runsvctrl(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 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, 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
# runsvctrl term /var/service/socklog-unix
or
# echo -n t >/var/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.
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. 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.
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.
runsvctrl(8), runsvstat(8),
chpst(8), svlogd(8), runit(8), runit-init(8), runsvdir(8), runsvchdir(8),
utmpset(8)
http://smarden.org/runit/
Gerrit Pape <pape@smarden.org>
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