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.

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: <NAME>
  namespace: <NAMESPACE>
spec:
  type: bindings.kafka
  version: v1
  metadata:
  - name: topics # Optional. in use for input bindings
    value: topic1,topic2
  - name: brokers
    value: localhost:9092,localhost:9093
  - name: consumerGroup
    value: group1
  - name: publishTopic # Optional. in use for output bindings
    value: topic3
  - name: authRequired # Required. default: "true"
    value: "false"
  - name: saslUsername # Optional.
    value: "user"
  - name: saslPassword # Optional.
    value: "password"
  - name: maxMessageBytes # Optional.
    value: 1024

Warning

The above example uses secrets as plain strings. It is recommended to use a secret store for the secrets as described here.

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,localhost:9093”`
consumerGroup	N	Input	A kafka consumer group to listen on	`“group1”`
publishTopic	Y	Output	The topic to publish to	`“mytopic”`
authRequired	Y	Input/Output	Determines whether to use SASL authentication or not. Defaults to `“true”`	`“true”`, `“false”`
saslUsername	N	Input/Output	The SASL username for authentication. Only used if `authRequired` is set to - `“true”`	`“user”`
saslPassword	N	Input/Output	The SASL password for authentication. Only used if `authRequired` is set to - `“true”`	`“password”`
maxMessageBytes	N	Input/Output	The maximum size 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"
      }'