Joachim Wiberg
b9ad9bcb21
The syntax overview no longer describes a line-based format, since that is not what the rest of the documentation shows. It now covers the grammar, the two naming conventions, the nine aliases, and the leading '-' on a path, and it says plainly that both formats are still read and told apart per file by content. Without that, a reader with an existing configuration is left wondering what happened to it. service-opts.md was a list of modifiers to place between a directive and its command, so it needed rewriting rather than translating: there are no positions left to describe. It is now grouped by what the settings do. conditions.md needed correcting. It presented '!' as a condition prefix alongside '~'. It is neither a condition nor a negation, it is a flag on the block that means one thing on a service and another on a run or task, so it is spelled reload-signal and required here, and the page maps the old form to both. Two things the pages claimed are not true. The kill delay range is 1-300, not 1-60, and stop and reload scripts are no longer run without a timeout. ChangeLog.md keeps its line-based examples. Those sit in historical release entries, and rewriting them in a syntax that did not exist at the time would misdate the format. Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
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SysV Init Compatibility
It is not possible to run unmodified SysV init systems with Finit. This was never the intention and is not the strength of Finit. However, it comes with a few SysV Init compatibility features to ease the transition from a serialized boot process.
SysV Init Scripts
Syntax: sysv [LVLS] <COND> /path/to/init-script -- Optional description
<COND>is described in the Services section.
Similar to task is the sysv stanza, which can be used to call SysV
style scripts. The primary intention for this command is to be able to
reuse much of existing setup and init scripts in Linux distributions.
When entering an allowed runlevel, Finit calls init-script start, when
entering a disallowed runlevel, Finit calls init-script stop, and if
the Finit .conf, where sysv stanza is declared, is modified, Finit
calls init-script restart on initctl reload. Similar to how
service stanzas work.
Forking services started with sysv scripts can be monitored by Finit
by declaring the PID file to look for: pidfile = "/path/to/file.pid".
Finit does not create that file, it watches it for the resulting
forked-off PID, which is the default; pidfile-create = true is what
asks Finit to write it instead. This
syntax also works for forking daemons that do not have a command line
option to run it in the foreground, more on this below in service.
Tip
See also SysV Init Compatibility.
runparts DIRECTORY
For a directory with traditional start/stop scripts that should run, in
order, at bootstrap, Finit provides the runparts directive. It runs
in runlevel S, at the very end of it (before calling /etc/rc.local)
making it perfect for most scenarios.
For syntax details, see the Run-parts Scripts section. Here is an example take from a Debian installation:
runparts /etc/rc2.d
Files in these directories are usually named SNNfoo and KNNfoo,
which Finit knows about and automatically appends the correct argument:
/bin/sh -c /etc/rc2.d/S01openbsd-inetd start
or
/bin/sh -c /etc/rc0.d/K01openbsd-inetd stop
Files that do not match this pattern are started similarly but without the extra command line argument.
Start/Stop Scripts
For syntax details, see SysV Init Scripts, above. Here follows an example taken from a Debian installation:
sysv inetd {
description = "OpenBSD inet daemon"
runlevel = "2345"
conditions = { "pid/syslogd" }
command = "/etc/init.d/openbsd-inetd"
}
The init script header could be parsed to extract Default-Start: and
other parameters for the sysv command to Finit. There is currently no
way to detail a generic syslogd dependency in Finit, so Should-Start:
in the header must be mapped to the condition system in Finit using an
absolute reference, here we depend on the sysklogd project's syslogd.
/etc/rc.local
One often requested feature, early on, was a way to run a site specific
script to set up, e.g., static routes or firewall rules. A user can add
a task or run command in the Finit configuration for this, but for
compatibility reasons the more widely know /etc/rc.local is used if
it exists, and is executable. It is called very late in the boot process
when the system has left runlevel S, stopped all old and started all new
services in the target runlevel (default 2).
In Finit releases before v4.5 this script blocked Finit execution and made it as good as impossible to call
initctlduring that time.
init q
When /sbin/finit is installed as /sbin/init, it is possible to use
init q to reload the configuration. This is the same as calling
initctl reload.