How to use metadata field in templates like path?

[0akarma]

I have noticed that vector have supported setting metadata field like %kafka.partition = del(.partition), but how can I use this metadata field in the template syntax?
I want to split file by kafka partition like path = "/output/%Y-%m-%d-%H-{{ %kafka.partition) }}.json.gz"

[jszwedko]

Hi @0akarma !

I believe that should work. I take it that it is not working for you though?

[spencergilbert]

%kafka.partition implies it's stored in the metadata, where the partition_key is stored on the event itself (at least until log namespacing is enabled).

[jszwedko]

Ah, I see. I may have misread their question. I thought they were setting %kafka.partition in a remap transform (via %kafka.partition = del(.partition)) but maybe they were just offering that as an example.

[spencergilbert]

Oh, I also might have misread it then 😅 - then I would expect it to work as provided as well (removing the stray ) that got added after the word partition though)

[spencergilbert]

Hey @0akarma - I believe the configuration you want to use is:

path = "/output/%Y-%m-%d-%H-{{ .partition }}.json.gz"