filter program logs in freebsd syslog

I had the need to filter logs from different programs into different places - in this case the postgres and nginx logs. The man page of syslog.conf describes it pretty good, but misses some examples to make it more clear. So here is how I configured it, to make it easier.

First, I edited the syslog.conf

# filter everything apart from postgres and nginx
*.err;kern.warning;auth.notice;mail.crit    /dev/console
# and all the other stuff

# filter only postgres
*.*        /var/log/postgresql.log

# filter only nginx
*.*        /var/log/nginx.log

The next step is to setup the log rotate. This happens in /etc/newsyslog.conf. The man page is very helpful, so if you want to adjust something, take a peek into it.

# postgresql                                                                                                                                                                                  
/var/log/postgresql.log     640  5     100  * JC                                                                                                                                              

# nginx                                                                                                                                                                                       
/var/log/nginx.log      640  5     100  * JC

And that is all. If you want to add more program filtes, you have to define them in the syslog.conf as notfilter and filter and add the rotate to newsyslog.conf.