user-defined-sinks.md

User Defined Sinks

A Pipeline may have multiple Sinks, those sinks could either be a pre-defined sink such as kafka, log, etc., or a User Defined Sink.

A pre-defined sink vertex runs single-container pods, a user defined sink runs two-container pods.

A user defined sink vertex looks like below.

spec:
  vertices:
    - name: output
      sink:
        udsink:
          container:
            image: my-sink:latest

Available Environment Variables

Some environment variables are available in the user defined sink container:

• NUMAFLOW_NAMESPACE - Namespace.
• NUMAFLOW_POD - Pod name.
• NUMAFLOW_REPLICA - Replica index.
• NUMAFLOW_PIPELINE_NAME - Name of the pipeline.
• NUMAFLOW_VERTEX_NAME - Name of the vertex.