On Sun, 5 Sep 2021 16:51:46 +1000 Nathan Scott <nath...@redhat.com> wrote:
Hi Petter,
On Sun, Sep 5, 2021 at 4:45 PM Petter Reinholdtsen <p...@hungry.com> wrote:
> [...] This approach is known as multilevel configuration.
>
> I recommend it over modifying conffiles in /etc/.
I'll discuss with other upstream folks and see if we can transition
to this style of solution & for all distros. It's a fairly major change,
so it won't happen overnight, but I agree it is a good way to tackle
this.
There is a simpler solution. The configuration option in question is an
environment variable. This can be passed to the daemon by shipping a
systemd service configuration file in pmlogger packaging.
$ cat /usr/lib/systemd/system/pmlogger.service.d/pcp-zeroconf.conf
[Service]
Environment=PMLOGGER_INTERVAL=10
When the package pcp-zeroconf is removed, the configuration will be
restored to previous state and this is often desirable. This, however,
works only on systemd systems.
Handling Dynamic Values:
Alternatively, if the file needs to contain dynamically calculated
options, pmlogger.postint can generate the file
/etc/systemd/system/pmlogger.service.d/pcp-zeroconf.conf . This file
will need to be removed by pmlogger.postrm (for purge).
Test:
I have tested this solution as follows:
(comment out PMLOGGER_INTERVAL in /etc/default/pmlogger)
# systemctl daemon-reload
# systemctl show pmlogger.service | grep Environment
Environment=PMLOGGER_INTERVAL=10
# systemctl restart pmlogger.service
# systemctl status pmlogger.service
(pickup main PID from output)
# cat /proc/{pid}/environ | tr '\0' '\n' | grep PMLOGGER_INTERVAL
PMLOGGER_INTERVAL=10
Non-systemd systems:
In addition to this solution the change in pmlogger.postinst can be
confined to non-systemd systems:
# increase default pmlogger recording frequency
if [ ! -e /run/systemd ]; then
sed -i 's/^\#\ PMLOGGER_INTERVAL.*/PMLOGGER_INTERVAL=10/g'
/etc/default/pmlogger
fi
If better approach for non-systemd systems is desired, then we canpatch
the /etc/init.d/pmlogger (src: src/pmlogger/rc_pmlogger) to read more
environment files from, say, /etc/pmlogger/*.conf and
/usr/share/pmlogger/*.conf. Then pcp-zeoconf can install the file
/etc/pmlogger/pcp-zeroconf.conf.
Severity:
Currently, this bug is threatening to remove all of pcp, cockpit and
freedombox from Debian on October 10th. Please consider adopting some
solution to avoid this.
Thanks you for pcp!
--
Sunil
