A log driver is a container-runtime component that captures a container’s stdout and stderr streams and routes them to a configured destination or backend. It can reduce extraction effort, support routing, and preserve container context such as IDs, names, and output sources. section 4.5 section 4.11
Choose the driver and collection path according to the runtime and deployment environment:
- Use Docker’s Fluentd logging driver to send events using the forward protocol to Fluent Bit. section 4.5
- Expect Podman to default to journald; collect those records with Fluent Bit’s systemd plugin. section 4.5
- Fall back to a known accessible file when the runtime cannot use a Fluentd or Fluent Bit-compatible driver. section 4.5
- Treat Kubernetes logging as runtime-dependent: cluster-wide collection commonly uses a sidecar or a node-level agent such as a DaemonSet. section 4.7.1
Send Docker logs to Fluent Bit
Configure Fluent Bit with a forward input on port 24224 and a stdout output, start it with `fluent-bit -c ./fluentbit/docker-log-driver-out.conf`, then run `docker run --log-driver=fluentd --log-opt fluentd-address=localhost:24224 hello-world`. The console receives log records containing fields such as `container_id`, `container_name`, `source`, and `log`. section 4.5
Listing 4.3 Receiving Docker log events: docker-log-driver-out.conf
[SERVICE] flush 1 [INPUT] name forward #1 port 24224 listen 0.0.0.0 [OUTPUT] #2 name stdout match *
Inspect the minimal Fluent Bit configuration that receives Docker forward events and writes every record to stdout. section 4.5
