syslog-ng installation

You will need syslog-ng >= 3.7.x

If your favorite Linux distribution does not provide a recent enough version read this

In a nutshell, below is an example for Ubuntu / Debian

Add the repo keys:

$ wget -qO -  http://download.opensuse.org/repositories/home:/laszlo_budai:/syslog-ng/xUbuntu_16.04/Release.key | sudo apt-key add -

Add the repo sources:

$ vim /etc/apt/sources.list.d/syslog-ng-obs.list

deb  http://download.opensuse.org/repositories/home:/laszlo_budai:/syslog-ng/xUbuntu_16.04 ./

Pin down version:

$ vim /etc/apt/preferences.d/syslog-ng

Package: syslog-ng-core
Pin: origin "download.opensuse.org"
Pin: version 3.7.*
Pin-Priority: 550

Package: syslog-ng-mod-python
Pin: origin "download.opensuse.org"
Pin: version 3.7.*
Pin-Priority: 550

Finally update and install:

$ apt-get update
$ apt-get install syslog-ng-core syslog-ng-mod-python

Note, syslog-ng-mod-python has been introduced in syslog-ng 3.7.x