Insert text into certain logs going to a 3rd party?

[eblackburn]

I'm looking to insert some text at our heavy forwarder into certain sourcetypes that a 3rd party running syslog-ng will see and be able to better identify what the logs are. For example, "IISLog", or "DHCPLog". Does anyone have any experience doing this?

Here's a sample log:

2021-01-26 20:12:28 192.168.58.11 POST /PerspectiveServices/SecureService.asmx - 443 - 192.168.49.24 Mozilla/4.0+(compatible;+MSIE+6.0;+SV1;+MS+Web+Services+Client+Protocol+4.0.30319.42000) - 200 0 0 26

This is an IIS log. I'd like to add the text somewhere (anywhere) into these logs. If it works, I'll do the same with some other sourcetypes. So the end result might be:

2021-01-26 20:12:28 192.168.58.11 IISLog POST /PerspectiveServices/SecureService.asmx - 443 - 192.168.49.24 Mozilla/4.0+(compatible;+MSIE+6.0;+SV1;+MS+Web+Services+Client+Protocol+4.0.30319.42000) - 200 0 0 26

We are sending them the logs from a heavy forwarder using syslog output. I was looking into potentially using SEDCMD within a props.conf file, but I'm not too experienced with doing this, and just getting started with RegEx.

[scelikok · Accepted solution]

Hi @eblackburn,

You use below sample. It is adding some text to end of the log since it is safer and easier.

props.conf
[iis_log]
TRANSFORMS-logtype = append_logtype

transforms.conf
[append_logtype]
REGEX = (?m)^(.*)$
FORMAT = $1 IISLog
DEST_KEY = _raw