How to extract a new field from 'source' (or others metadata) fields?

[tcmarquesi]

I need to extract a field that is a substring from 'source' field. My intention was to use something like a regex in transforms.conf, but seems I can't do it because 'source' is metadata. So, once 'source' is not in raw event, what is the better (or only) way to do this extraction?

[gcusello]

Hi bshuler [Splunk]
if you want to maintain the original source and create a new field, you could extract this field in your search

your_search | rex field=source "your_regex"

or using the web field extraction inserting in the regex

your_regex in source

Bye.
Giuseppe

[bshuler_splunk · Accepted solution]

SOURCE_KEY = MetaData:Source

[tcmarquesi]

Thank you!

I should had read more the docs before asking... lol