[Pdns-users] Alternative way to log in pdns_recursor when OS holds Syslog hostage

[Brian Candler]

On 04/11/2017 05:22, Nick Williams wrote:
> If I start `/usr/sbin/pdns_recursor --daemon=no --write-pid=no --disable-syslog=no` manually from the command prompt (as root), it logs to syslog-ng perfectly. If I start it with `systemctl start pdns-recursor`, it does not log to syslog-ng no matter what I do.

Assuming that the systemd unit file is starting pdns_recursor with the 
right flags - which it seems to be according to your ps output - then 
the two most likely differences are:

1. something to do with running as pdns user.  Try switching to the pdns 
user (with su) before starting pdns_recursor at the command line, and 
see if you get any additional output, and whether it can write to logs.

2. something to do with environment variables, although I'm not aware of 
any that pdns_recursor needs.

You could also try attaching strace to the pdns_recursor process to see 
if you can see its attempts to find or open the log; that depends 
whether your tiny Linux distro has strace though.

I am guessing this tiny Linux doesn't do SELinux or AppArmor, but might 
be worth checking.

Sorry can't be more specific; those are just general Linux debugging hints.