Package: pdns-recursor Version: 2.9.17-10 Severity: normal Tags: patch First I report some problems, then I suggest a solution. :)
* On stop, resolvconf is told to delete the resolvconf record after the
daemon is stopped. It would be better to do this before the daemon is
stopped so that no new queries are sent to the daemon just when it is
about to be killed.
* The record should be called 'lo.pdns-recursor' so that it does not
conflict with records created by other nameservers which could
conceivably by running on the same machine. (pdns-recursor does not
Conflict with any other packages, so I infer that this is possible.
Anyway, there is no reason not to give the record a unique name.)
* Currently in the stop method the initscript sends a signal and then
exits immediately and unconditionally. However, the script should not
exit before the daemon has really stopped. More precisely, it should
not exit before the daemon releases resources that could be needed by
other daemons that are starting in the same runlevel change or dpkg run.
Furthermore, if the daemon could not be stopped then the script should
exit with an error status. (Admittedly, many initscripts in Debian
have this shortcoming.)
* On restart, a "sleep 3" is used to ensure that the daemon is restarted
after it is stopped. This either wastes time or is unreliable. For
the same reason, the previous problem isn't best solved by adding a
sleep to the end of the stop method.
* The script does "test -x $DAEMON" runs the daemon using $NAME, which
is inconsistent.
* The daemon is started using the command
$NAME --daemon 2>&1 /dev/null
As the daemon does not take any non-option arguments (according to the
man page), I infer that you really meant to do:
$NAME --daemon 2>&1 >/dev/null
However, I don't see why you want to hide the daemon's rather brief
startup message.
[EMAIL PROTECTED]:~$ sudo /usr/sbin/pdns_recursor --daemon
Apr 16 18:53:50 Incoming query source port: 53
Apr 16 18:53:50 Done priming cache with root hints
The cost is great: you also hide the daemon's error messages, if any.
If the startup messages are superfluous then the daemon source should
be patched in order to suppress them.
* Neither the daemon nor the initscript deletes the pidfile on stop.
* Solution
I wrote the initscripts for dnsmasq and pdnsd which, although possibly
imperfect, are less imperfect. Each uses start-stop-daemon to test for
running instances of the daemon, properly handles various failure cases
and interfaces with resolvconf correctly. I attach an initscript like
theirs for pdns-recursor.
I have implemented the "Don't really start unless a certain environment
variable is set to a certain value" feature even though I don't like it
when maintainers try to undermine the standard mechanism for enabling
and disabling services in runlevels. :/
If you find any problems with the initscript then please discuss them
with me. If the problem turns out to be real then I would like to fix
any similar problems in the dnsmasq and/or pdnsd initscripts.
The following log shows that the initscript works. The daemon does
produce ugly messages, but as I said earlier, these should be dealt
with in the daemon source. One possibility would be to change the
daemon to print them on standard output rather than on standard
error and then divert only standard output to /dev/null. This would
eliminate the unwanted startup messages without hiding error messages.
# # Note that in the following case START is unset
# ./pdns-recursor start
Not starting PowerDNS recursor -- disabled.
# START=yes ./pdns-recursor start
Starting PowerDNS recursor: pdns_recursorApr 16 19:26:55 Incoming query
source port: 53
Apr 16 19:26:55 Done priming cache with root hints
.
# START=yes ./pdns-recursor start
Starting PowerDNS recursor: pdns_recursor (already running).
# ./pdns-recursor stop
Stopping PowerDNS recursor: pdns_recursor.
# ./pdns-recursor stop
Stopping PowerDNS recursor: pdns_recursor (not running).
# START=yes ./pdns-recursor restart
Restarting PowerDNS recursor: pdns_recursorApr 16 19:27:19 Incoming
query source port: 53
Apr 16 19:27:19 Done priming cache with root hints
.
# START=yes ./pdns-recursor restart
Restarting PowerDNS recursor: pdns_recursorApr 16 19:27:21 Incoming
query source port: 53
Apr 16 19:27:21 Done priming cache with root hints
.
# # Note that in the following cases START is unset
# ./pdns-recursor restart
Stopping PowerDNS recursor: pdns_recursor.
# ./pdns-recursor restart
Stopping PowerDNS recursor: pdns_recursor (not running).
-- System Information:
Debian Release: 3.1
APT prefers testing
APT policy: (500, 'testing'), (50, 'unstable'), (1, 'experimental')
Architecture: i386 (i686)
Kernel: Linux 2.6.11
Locale: [EMAIL PROTECTED], [EMAIL PROTECTED] (charmap=ISO-8859-15)
Versions of packages pdns-recursor depends on:
ii libc6 2.3.2.ds1-20 GNU C Library: Shared libraries an
ii libgcc1 1:3.4.3-12 GCC support library
ii libstdc++5 1:3.3.5-8 The GNU Standard C++ Library v3
-- no debconf information
pdns-recursor
Description: application/shellscript
