Re: spiped process matching on OpenBSD

["Jared Harper" <jared@hrpr.us>]

Yes, I ended up successfully escaping the square brackets before. However,
your suggestion makes me realize that my target of matching the whole
daemon+daemon_flags set is probably unnecessary, all I need to match is the
-s, which should be unique on the host.

Thanks!

P.S. I looked at `setproctitle` a bit more and realized that it's really,
_really_ un-portable so that's definitely not an option.

On Sat, Apr 8, 2023, at 7:32 PM, Graham Percival wrote:
> Hi Jared,
>
> Sorry if this seems like "too obvious" of a solution, but have you tried
> escaping the square brackets with \ ?  i.e.
>
>     pexp="${daemon} -s \[127.0.0.1\] .*"
>
> or something like that?
>
> I'm not familiar with rc files, so it's possible that they use a different
> character for escaping, but I'm certain they have that capability somehow.
>
> Cheers,
> - Graham
>
> On Sat, Apr 08, 2023 at 03:22:25PM -0700, Jared Harper wrote:
>> I have spiped running on two OpenBSD 7.2 hosts, installed via `pkg_add`,
>> and it works great.
>> 
>> The port's rc script for spiped, however, is only usable for a single
>> instance because it sets `pexp="${daemon} .*"`[1], which will match
>> every running instance of spiped. 
>> 
>> (For those unfamiliar with `pexp`, it is the regex used to identify a
>> running process via `pgrep`. OpenBSD's rc system relies on this process
>> matching method and does not support pid files.)
>> 
>> I spent some time trying to configure the pexp to not be so greedy by
>> using the default `${daemon} ${daemon_flags}`.  This approach is
>> unsuccessful due to the brackets surrounding the IP address (e.g.,
>> `[127.0.0.1]`) becoming a regex matching list.
>> 
>> Some options I could use to workaround this limitation:
>> 
>> 1) Use hostnames and no brackets; This apparently works but it limits
>> usefulness.
>> 
>> 2) Manually set `pexp`; This does work but requires that I remember to
>> update it whenever the `daemon_flags` change. Also, across multiple
>> processes this becomes borderline umaintainable.
>> 
>> (Unfortunately, using the pidfile is a no-go because of how the rc
>> subroutines use `pexp` in multiple places.)
>> 
>> Since the primary author of spiped is a long-time contributor to
>> FreeBSD, and FreeBSD supports pidfiles in their rc-system[2], I want to
>> be clear I'm not saying that spiped does anything wrong, or that OpenBSD
>> is doing something right. I just want to come up with a solution that I
>> can contribute to the OpenBSD port so that we don't have to have this
>> issue.
>> 
>> A potential solution I can see would be to support `setproctitle(3)`[3]
>> via a flag, such as `--name <name>`, which could result in a process
>> title like `spiped: myname`.  What's the appetite for this sort of
>> change?
>> 
>> However, since I'm new to a lot of these technologies, I'm fairly
>> certain I've missed something obvious or easy (other than "switch to
>> FreeBSD" ;). Do you have any other ideas? 
>> 
>> Thanks in advance. 
>> 
>> [1]: https://github.com/openbsd/ports/blob/master/security/spiped/pkg/spiped.rc#L9
>> [2]: https://man.freebsd.org/cgi/man.cgi?rc.subr(8)
>> [3]: https://man.freebsd.org/cgi/man.cgi?query=setproctitle&sektion=3&format=html
>> 
>> -jh

-- 
-jh