Serving via rc on OpenBSD

<title>Serving via rc on OpenBSD</title>

OpenBSD provides [https://man.openbsd.org/rc.subr.8|rc.subr(8)],
a framework for writing [https://man.openbsd.org/rc.8|rc(8)] scripts.

<h2>Creating the daemon</h2>

Create the file /etc/rc.d/fossil with contents like the following.

<pre>
#!/bin/ksh
daemon="/usr/local/bin/fossil" # fossil executable
daemon_user="_fossil" # user to run fossil as
daemon_flags="server /home/_fossil/example --repolist --port 8888" # fossil command

. /etc/rc.d/rc.subr
# pexp="$daemon server .*" # See below.
rc_reload=NO # Unsupported by Fossil; 'rcctl reload fossil' kills the process.
rc_bg=YES # Run in the background, since fossil serve does not daemonize itself
rc_cmd $1
</pre>

<h3>pexp</h3>

You may need to uncomment the "pexp=". rc.subr typically
finds the daemon process based by matching the process name and argument list.
Without the "pexp=" line, rc.subr would look for this exact command:

<pre>
/usr/local/bin/fossil server /home/_fossil/example --repolist --port 8888
</pre>

Depending on the arguments and their order, fossil may rewrite the arguments
for display in the process listing ([https://man.openbsd.org/ps.1|ps(1)]),
so rc.subr may fail to find the process through the default match. The example
above does not get rewritten, but the same commands in a different order can
be rewritten.
For example, when I switch the order of the arguments in "daemon_flags",

<pre>
/usr/local/bin/fossil server --repolist --port 8888 /home/_fossil/example
</pre>

the process command is changed to this.

<pre>
/usr/local/bin/fossil server /home/_fossil/example /home/_fossil/example 8888 /home/_fossil/example
</pre>

The commented "pexp=" line instructs rc.subr to choose the process whose
command and arguments text starts with this:

<pre>
/usr/local/bin/fossil server 
</pre>

<h2>Enabling the daemon</h2>

Once you have created /etc/rc.d/fossil, run these commands.

<pre>
rcctl enable fossil # add fossil to pkg_scripts in /etc/rc.conf.local
rcctl start fossil # start the daemon now
</pre>

The daemon should now be running and set to start at boot.

<h2>Multiple daemons</h2>

You may want to serve multiple fossil instances with different options.
For example,

  *  If different users own different repositories, you may want different users
     to serve different repositories.
  *  You may want to serve different repositories on different ports so you can
     control them differently with, for example, HTTP reverse proxies or
     [https://man.openbsd.org/pf.4|pf(4)].

To run multiple fossil daemons, create multiple files in /etc/rc.d, and
enable each of them. Here are two approaches for creating
the files in /etc/rc.d: Symbolic links and copies.

<h3>Symbolic links</h3>

Suppose you want to run one fossil daemon as user "user1" on port 8881
and another as user "user2" on port 8882. Create the files with
[https://man.openbsd.org/ln.1|ln(1)], and configure them to run different
fossil commands.

<pre>
cd /etc/rc.d
ln -s fossil fossil1
ln -s fossil fossil2
rcctl enable fossil1 fossil2
rcctl set fossil1 user user1
rcctl set fossil2 user user2
rcctl set fossil1 flags 'server /home/user1/repo1.fossil --port 8881'
rcctl set fossil2 flags 'server /home/user2/repo2.fossil --port 8882'
rcctl start fossil1 fossil2
</pre>

<h3>Copies</h3>

You may want to run fossil daemons that are too different to configure
just with [https://man.openbsd.org/rcctl.8|rcctl(8)].
In particular, you can't change the "pexp" with rcctl.

If you want to run fossil commands that are more different,
you may prefer to create separate files in /etc/rc.d.
Replace "ln -s" above with "cp" to accomplish this.

<pre>
cp /etc/rc.d/fossil /etc/rc.d/fossil-user1
cp /etc/rc.d/fossil /etc/rc.d/fossil-user2
</pre>

You can still use commands like "rcctl set fossil-user1 flags", but you
can also edit the "/etc/rc.d/fossil-user1" file.