I think I may have misunderstood how that worked. We are running sling inside kubernetes cronjobs and using

Loki

to get the pod logs. Is there a way to get the console logs in JSON format?

yes, set env var

SLING_LOGGING=JSON

I have the following set in my replication.yaml

...
        select: [-password]
    env:
      SLING_THREADS: 1
      SLING_LOGGING: JSON

This does not seem to have taken effect.

Yeah, it's because the logger inits before the replication is loaded. Can you try setting at shell level?

Yepp, that fixed it