Ubuntu Manpage: invoke-run - runscript interpreter

Provided by: runit_2.1.2-44ubuntu2_amd64

NAME

       invoke-run - runscript interpreter

SYNOPSIS

       /usr/bin/env /lib/run/invoke-run

DESCRIPTION

The runit supervision system uses scripts, called runscripts to start services. By convention, runscript
for a service foo is located at /etc/sv/foo/run

Debhelper addon dh_runit installs runscript according this convention.

Runscript can be any executable file. Runscript can use invoke-run interpreter only if it is installed
according convention,

To use invoke-run interpreter, runscript /etc/sv/foo/run for service foo must begin with following line:

#!/usr/bin/env /lib/runit/invoke-run

If the script /usr/sbin/policy-rc.d exists the policy layer is checked (see below). If init.d script
/etc/init.d/foo exists, it is invoked with stop argument to gracefully handle package upgrade to version,
introducing runscript. After that, /bin/sh shell interpret rest of runscript, with some additional
environment set according following rules:

A NAME=foo variable is exported.

The /etc/default/runit file is interpreted with /bin/sh and all variable assignment are accessible to
runscript.

If file /etc/default/foo exists, it is interpreted with /bin/sh and all variable assignment are
accessible to runscript.

If directory /etc/sv/foo/conf exists, variables are set according to rules, documented in envdir
section of chpst(8) manual.

If both /etc/default/foo file and /etc/sv/foo/conf directory define some variable, value from directory
takes precedence.

SPECIAL ERROR CODE

       Looking in the foo service log it's possible to see messages in the form of

         invoke-run: ERROR [NNN] in foo: reason for the error

       These messages don't come from runsv itself but from invoke-run, the run file or  the  finish  file.  The
       purpose  of these message is to detail a permanent failure condition that prevents foo service from being
       up.  For each foo service, possible errors and messages are:

         invoke-run: foo binary not installed

           this happens when the package containing foo binary has been removed, but not purged.

         invoke-run: ERROR -1 in foo: runscript didn't exit normally

           this message comes from the finish file, but the exit code comes from runsv(8) and is  documented  in
           its manpage.

         invoke-run: WARNING for foo: disabled by local settings

           Some service specific setting prevent foo from starting; it's likely something in /etc/default/foo

         invoke-run: ERROR 162 in foo: configtest or early setup failed

           A  configuration  file  of foo is malformed and the configtest failed; foo log may contain additional
           info from the test itself.  Alternatively the runscript has failed to do some setup that is essential
           to the foo service.

         invoke-run: ERROR 170 in foo: a runtime hard dependency is missing

           A dependency failed the check and can't be bring up; to know dependencies of foo service look for "sv
           start" in "run" script.

FINISH FILE AND FINISH-DEFAULT

       Since version 2.1.2-36 the Debian runit package ships a /lib/runit/finish-default file that contains code
       that can be shared across different services.  This file can be sourced inside the regular finish file of
       a service, like the following example

        $ cat /etc/sv/foo/finish
        #!/bin/sh
        set -e
        . /lib/runit/finish-default "$@"

       Services that need to put specific code into the finish file  should  do  after  the  line  that  sources
       finish-default.  For  each foo service, finish-default file sources /etc/default/runit, export a NAME=foo
       variable and defines special error codes as described in the previous section.  Also, when  VERBOSE  mode
       is on, EXIT is trapped so that a 'foo stopped' message gets printed at the very end of the finish file.

POLICY-RC.D LAYER