Need help specifying args in rc.conf for a service

[Scott]

On Mon, Jan 11, 2021 at 01:21:07PM +0100, Polytropon wrote:
> On Mon, 11 Jan 2021 22:57:23 +1100, Scott wrote:
> > Hi all,
> > 
> > I posted this on the forums and was unsuccessful so I thought I'd try here:
> > 
> > I've been struggling to pass additional arguments to the Prometheus 
> > node_exporter daemon in /etc/rc.conf.
> > 
> > The help for node_exporter provides an example argument (mount points to 
> > ignore) as:
> > 
> > --collector.filesystem.ignored-mount-points="^/(dev)($|/)"
> >                                 Regexp of mount points to ignore for filesystem collector.
> > 
> > The rc script says to use the _args variable to specify arguments to 
> > node_exporter:
> > # node_exporter_args (string):          Set extra arguments to pass to 
> > # Default is "".
> > 
> > Adding the line:
> > 
> > node_exporter_args="--collector.filesystem.ignored-mount-points=\"^/(dev)($|/)\""
> > 
> > to /etc/rc.conf and running sh -x /usr/local/etc/rc.d/node_exporter start 
> > results in:
> > 
> > + limits -C daemon su -m nobody -c 'sh -c "/usr/sbin/daemon  -f -p /var/run/node_exporter.pid -T node_exporter     /usr/bin/env /usr/local/bin/node_exporter     --web.listen-address=:9100     --collector.textfile.directory=/var/tmp/node_exporter     --collector.filesystem.ignored-mount-points="^/(dev)($|/)""'
> > 
> > Illegal variable name.
> > 
> > [...]
> > 
> > Can anyone please help?
> 
> If I see this correctly, the argument given to to the program's
> option --collector.filesystem.ignored-mount-points= is to be a
> regex, not the result of evaluating the regex (which the program
> surely does internally). So my suggestion, without knowing any
> further details, is to use this in /etc/rc.conf:
> 
> 	node_exporter_args='--collector.filesystem.ignored-mount-points="^/(dev)($|/)"'
> 
> Always remember that /etc/rc.conf is, more or less, just a simple
> shell script, so all rules applying to sh will apply to rc.conf
> exactly. That's why 'single quotes' will stop any expansion and
> transfer the value 1:1, which I think is what you are require to
> do here. Characters such as $, " or ^ will be part of the string
> handed over to the program, and will _not_ be interpreted by the
> shell prior to assigning to the _args variable.
> 
> Within "double quotes", symbols such as $ have a specific meaning,
> that's why you see the error ($ not properly quoted). So the
> error message is completely valid and logical - and expected. ;-)
> 
> 
> 
> 
> -- 
> Polytropon
> Magdeburg, Germany
> Happy FreeBSD user since 4.0
> Andra moi ennepe, Mousa, ...
>
Thanks Poly,

here's what I get using:
        node_exporter_args='--collector.filesystem.ignored-mount-points="^/(dev)($|/)"'

+ _doit=$' limits -C daemon su -m nobody -c \'sh -c "/usr/sbin/daemon  -f -p /var/run/node_exporter.pid -T node_exporter     /usr/bin/env /usr/local/bin/node_exporter     --web.listen-address=:9100     --collector.textfile.directory=/var/tmp/node_exporter     --collector.filesystem.ignored-mount-points="^/(dev)($|/)""\''
+ _run_rc_doit $' limits -C daemon su -m nobody -c \'sh -c "/usr/sbin/daemon  -f -p /var/run/node_exporter.pid -T node_exporter     /usr/bin/env /usr/local/bin/node_exporter     --web.listen-address=:9100     --collector.textfile.directory=/var/tmp/node_exporter     --collector.filesystem.ignored-mount-points="^/(dev)($|/)""\''
+ debug $'run_rc_command: doit:  limits -C daemon su -m nobody -c \'sh -c "/usr/sbin/daemon  -f -p /var/run/node_exporter.pid -T node_exporter     /usr/bin/env /usr/local/bin/node_exporter     --web.listen-address=:9100     --collector.textfile.directory=/var/tmp/node_exporter     --collector.filesystem.ignored-mount-points="^/(dev)($|/)""\''
+ eval $' limits -C daemon su -m nobody -c \'sh -c "/usr/sbin/daemon  -f -p /var/run/node_exporter.pid -T node_exporter     /usr/bin/env /usr/local/bin/node_exporter     --web.listen-address=:9100     --collector.textfile.directory=/var/tmp/node_exporter     --collector.filesystem.ignored-mount-points="^/(dev)($|/)""\''
+ limits -C daemon su -m nobody -c 'sh -c "/usr/sbin/daemon  -f -p /var/run/node_exporter.pid -T node_exporter     /usr/bin/env /usr/local/bin/node_exporter     --web.listen-address=:9100     --collector.textfile.directory=/var/tmp/node_exporter     --collector.filesystem.ignored-mount-points="^/(dev)($|/)""'
Illegal variable name.

Thanks