Cardano => Kafka

This guide walks through streaming data from a Cardano node into a Kafka topic with Oura — a typical setup for feeding chain data into an existing stream-processing platform.

Kafka needs a custom build

The Kafka sink isn’t in the default binary. Build Oura with the kafka feature first — see Install from source.

Prerequisites

• A running Cardano node, reachable locally via a unix socket.
• A Kafka cluster reachable over the network, with the destination topic already created.
• Oura installed with the kafka feature enabled.

Instructions

1. Create a config file named cardano2kafka.toml:

   cardano2kafka.toml

   [source]
   type = "N2C"
   socket_path = "/opt/cardano/cnode/sockets/node0.socket"
   
   [sink]
   type = "Kafka"
   brokers = ["kafka-broker-0:9092"]
   topic = "cardano-events"

   What this configures:

   • [source] pulls chain data from your node.
     • N2C reads from the node over Node-to-Client mini-protocols (chain-sync in full-blocks mode).
     • socket_path is the path to your local node’s unix socket.
   • [sink] sends the data on.
     • Kafka uses a Kafka producer client as the output.
     • brokers lists the Kafka brokers; add several hostname:port pairs for a cluster.
     • topic is the topic to publish messages to.

2. Run Oura in daemon mode against the config:

   RUST_LOG=info oura daemon --config cardano2kafka.toml