For Scribe <-> Fluentd, there is fluent-plugin-scribe:
For Fluentd <-> Logstash, a couple of options:
- Use Redis in the middle, and use fluent-plugin-redis and input_redis on Logstash's side. So it would be Fluentd -> Redis -> Logstash. This is what Logstash recommends anyway with log shippers + Logstash.
- Alternatively, you can use Fluentd's out_forward plugin with Logstash's TCP input. Logstash has Fluentd codec to handle the input coming from Fluentd.