Q:

Configuring Logstash when installed as a service

I have installed logstash as a service using the logstash APT repository on Ubuntu 13.10.
So now I can run:
dpkg -s logstash

And it outputs:
Package: logstash
Status: install ok installed
Priority: extra
Section: default
Installed-Size: 93362
Maintainer: <jls@ds4172>
Architecture: all
Version: 1.4.0-1-c82dc09
Depends: java7-runtime-headless | java6-runtime-headless | j2re1.7
Conffiles:
 /etc/default/logstash 399f19c4d762840a36f6bc056c3739b8
 /etc/default/logstash-web d94db9f8dc1d4ced449175a96e8df09d
 /etc/logrotate.d/logstash 9bb11b4b058868bb41c658c9c3152a83
Description: An extensible logging pipeline
License: Apache 2.0
Vendor: Elasticsearch
Homepage: http://logstash.net

So I see that the logstash service was successfully installed.  
I know that running logstash (not as a service) I can specify a configuration like so:
bin/logstash -f /path/to/config-file

But how would I specify a specific configuration when I am running logstash as a service?

A:

you got configuration of logstash in directory /etc/logstash/conf.d/
You got all paths in /etc/init.d/logstash
# logstash configuration directory
CONF_DIR=/etc/logstash/conf.d
I got there file /etc/logstash/conf.d/logstash.conf which is automaticlly generated by puppet logstash module :)

