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Kafka binding spec

Detailed documentation on the Kafka binding component

Component format

To setup Kafka binding create a component of type bindings.kafka. See this guide on how to create and apply a binding configuration. For details on using secretKeyRef, see the guide on how to reference secrets in components.

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: kafka-binding
  namespace: default
spec:
  type: bindings.kafka
  version: v1
  metadata:
  - name: topics # Optional. Used for input bindings.
    value: "topic1,topic2"
  - name: brokers # Required.
    value: "localhost:9092,localhost:9093"
  - name: consumerGroup # Optional. Used for input bindings.
    value: "group1"
  - name: publishTopic # Optional. Used for output bindings.
    value: "topic3"
  - name: authRequired # Required.
    value: "true"
  - name: saslUsername # Required if authRequired is `true`.
    value: "user"
  - name: saslPassword # Required if authRequired is `true`.
    secretKeyRef:
      name: kafka-secrets
      key: saslPasswordSecret
  - name: maxMessageBytes # Optional.
    value: 1024

Spec metadata fields

Field Required Binding support Details Example
topics N Input A comma-separated string of topics. "mytopic1,topic2"
brokers Y Input/Output A comma-separated string of Kafka brokers. "localhost:9092,dapr-kafka.myapp.svc.cluster.local:9093"
consumerGroup N Input A kafka consumer group to listen on. Each record published to a topic is delivered to one consumer within each consumer group subscribed to the topic. "group1"
publishTopic Y Output The topic to publish to. "mytopic"
authRequired Y Input/Output Enable SASL authentication with the Kafka brokers. "true", "false"
saslUsername N Input/Output The SASL username used for authentication. Only required if authRequired is set to "true". "adminuser"
saslPassword N Input/Output The SASL password used for authentication. Can be secretKeyRef to use a secret reference. Only required if authRequired is set to "true". "", "KeFg23!"
maxMessageBytes N Input/Output The maximum size in bytes allowed for a single Kafka message. Defaults to 1024. 2048

Binding support

This component supports both input and output binding interfaces.

This component supports output binding with the following operations:

  • create

Specifying a partition key

When invoking the Kafka binding, its possible to provide an optional partition key by using the metadata section in the request body.

The field name is partitionKey.

Example:

curl -X POST http://localhost:3500/v1.0/bindings/myKafka \
  -H "Content-Type: application/json" \
  -d '{
        "data": {
          "message": "Hi"
        },
        "metadata": {
          "partitionKey": "key1"
        },
        "operation": "create"
      }'
Last modified November 24, 2021 : Merge pull request #1993 from tanvigour/v1.3 (a919b47)