This QuickStart assumes that you have created a StreamNative cluster with the Kafka protocol enabled, created a service account, and granted the service account produce and consume permissions to a namespace for the target topic.
This document describes how to connect to your StreamNative cluster using the Kafka Node.js client using API Keys authentication.

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Before you begin

  • Before using an API key, verify that the service account is authorized to access the resources, such as tenants, namespaces, and topics.
  • The password for different utilities as kcat will be equal to token:<API KEY>.
You can follow the instructions to create an API key for the service account you choose to use.

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Steps

  1. Install the Kafka Nodejs client. 
    npm install kafkajs
  2. Build a Nodejs application to produce and consume messages. 
    const { Kafka } = require('kafkajs')

// Step 1: replace with your configurations
let serverUrl = 'SERVER-URL'
let jwtToken = 'API-KEY'
let topicName = 'test-js-topic'
let namespace = 'public/default'

// Step 2: create the kafka client
const kafka = new Kafka({
  clientId: 'my-app',
  brokers: [serverUrl],
  ssl: true,
  sasl: {
    mechanism: 'plain',
    username: namespace,
    password: 'token:' + jwtToken,
  },
})

// Step 3: send a message to your topic
async function send() {
  const producer = kafka.producer()
  await producer.connect()

  let resp = await producer.send({
    topic: topicName,
    messages: [
      {
        value: 'Hello KafkaJS user!',
      },
    ],
  })

  console.log(`Send message:`, resp)

  await producer.disconnect()
}

// Step 4: read messages from the beginning of your topic
async function receive() {
  const consumer = kafka.consumer({
    groupId: 'my-group',
    readUncommitted: true, // Note: Ursa does not support read_committed for now
  })
  await consumer.connect()
  console.log('Connected to Kafka')

  await consumer.subscribe({ topic: topicName, fromBeginning: true })

  await consumer.run({
    eachMessage: async ({ topic, partition, message }) => {
      console.log(`Received message:`, {
        value: message.value.toString(),
        headers: message.headers,
        topic: topic,
        partition: partition,
        offset: message.offset,
      })
    },
  })
}

// Step 5: send one message then receive
send().then(function () {
  receive()
})
    • SERVER-URL: the Kafka service URL of your StreamNative cluster.
    • API-KEY: an API key of your service account.
  3. Run the Node.js application with your saved scripts. This example runs the Node.js application assuming that you save the scripts as kop_test.js. 
    node kop_test.js
    You should see the following output: 
    Send message: [
  {
    topicName: 'test-js-topic',
    partition: 0,
    errorCode: 0,
    baseOffset: '7',
    logAppendTime: '-1',
    logStartOffset: '-1'
  }
]
Connected to Kafka
Received message: {
  value: 'Hello KafkaJS user!',
  headers: {},
  topic: 'test-js-topic',
  partition: 0,
  offset: '0'
}
...