Connect to Pulsar cluster using Node.js client

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Connect to a Pulsar cluster using a token

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Prerequisites

• Get the service URL.
• Get a service account token.

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Steps

1. Connect to the Pulsar cluster.
   const Pulsar = require('pulsar-client')
   const auth_params = process.env.AUTH_PARAMS
   const service_url = process.env.SERVICE_URL
   
   ;(async () => {
     const auth = new Pulsar.AuthenticationToken({
       token: 'AUTH_PARAMS',
     })
   
     // Create a client
     const client = new Pulsar.Client({
       serviceUrl: 'your-service-url',
       authentication: auth,
       operationTimeoutSeconds: 30,
     })
   
     await client.close()
   })()
   
   Set the serviceUrl and token parameters based on the descriptions in the prepare to connect to a Pulsar cluster user guide.
2. Create a Node.js consumer and use the Node.js consumer to consume messages.
   const Pulsar = require('pulsar-client')
   const auth_params = process.env.AUTH_PARAMS
   const service_url = process.env.SERVICE_URL
   
   ;(async () => {
     const auth = new Pulsar.AuthenticationToken({
       token: 'AUTH_PARAMS',
     })
   
     // Create a consumer
     const consumer = await client.subscribe({
       topic: 'your-topic',
       subscription: 'your-sub-name',
       subscriptionType: 'Shared',
       ackTimeoutMs: 10000,
     })
   
     // Receive messages
     for (let i = 0; i < 10; i += 1) {
       const msg = await consumer.receive()
       console.log(msg.getData().toString())
       await consumer.acknowledge(msg)
     }
   
     await consumer.close()
     await client.close()
   })()
   
3. Create a Node.js producer and use the Node.js producer to produce messages.
   const Pulsar = require('pulsar-client')
   const auth_params = process.env.AUTH_PARAMS
   const service_url = process.env.SERVICE_URL
   
   ;(async () => {
     const auth = new Pulsar.AuthenticationToken({
       token: 'AUTH_PARAMS',
     })
   
     const producer = await client.createProducer({
       topic: 'your-topic',
       sendTimeoutMs: 30000,
       batchingEnabled: true,
     })
   
     // Send messages
     for (let i = 0; i < 10; i += 1) {
       const msg = `my-message-${i}`
       producer.send({
         data: Buffer.from(msg),
       })
       console.log(`Sent message: ${msg}`)
     }
     await producer.flush()
   
     await producer.close()
     await client.close()
   })()
   

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Connect to a Pulsar cluster using an OAuth2 credential file

1. Generate the App credentials by following similar instructions in configure OAuth2 authentication.
2. Save the App credentials into an OAuth2 credential file.
3. Connect to a Pulsar cluster through the OAuth2 credential file.
   const Pulsar = require('pulsar-client')
   const issuer_url = process.env.ISSUER_URL
   const private_key = process.env.PRIVATE_KEY
   const audience = process.env.AUDIENCE
   const scope = process.env.SCOPE
   const service_url = process.env.SERVICE_URL
   const client_id = process.env.CLIENT_ID
   const client_secret = process.env.CLIENT_SECRET
   
   ;(async () => {
     const params = {
       issuer_url: 'your-issuer-url',
     }
     if (private_key.length > 0) {
       params['private_key'] = 'file:///path/to/private-key-file.json'
     } else {
       params['client_id'] = 'your-client-id'
       params['client_secret'] = 'your-client-secret'
     }
     if (audience.length > 0) {
       params['audience'] = 'your-audience'
     }
     if (scope.length > 0) {
       params['scope'] = 'your-scope'
     }
     const auth = new Pulsar.AuthenticationOauth2(params)
     // Create a client
     const client = new Pulsar.Client({
       serviceUrl: 'pulsar-service-url',
       tlsAllowInsecureConnection: true,
       authentication: auth,
     })
     await client.close()
   })()
   
   • issuer_url: the URL of your OAuth2 identity provider.
   • private_key: the path to your OAuth2 credential file.
   • client_id: the Pulsar application client ID.
   • client_secret: the Pulsar application client secret.
   • audience: the audience of your Pulsar cluster.
   • serviceUrl: the URL of your Pulsar cluster.
4. Create a Node.js consumer and use the Node.js consumer to consume messages.
   const Pulsar = require('pulsar-client')
   const issuer_url = process.env.ISSUER_URL
   const private_key = process.env.PRIVATE_KEY
   const audience = process.env.AUDIENCE
   const scope = process.env.SCOPE
   const service_url = process.env.SERVICE_URL
   const client_id = process.env.CLIENT_ID
   const client_secret = process.env.CLIENT_SECRET
   
   ;(async () => {
     const params = {
       issuer_url: 'your-issuer-url',
     }
     if (private_key.length > 0) {
       params['private_key'] = 'file:///path/to/private-key-file.json'
     } else {
       params['client_id'] = 'your-client-id'
       params['client_secret'] = 'your-client-secret'
     }
     if (audience.length > 0) {
       params['audience'] = 'your-audience'
     }
     if (scope.length > 0) {
       params['scope'] = 'your-scope'
     }
     const auth = new Pulsar.AuthenticationOauth2(params)
   
     const consumer = await client.subscribe({
       topic: 'your-topic',
       subscription: 'your-sub-name',
       subscriptionType: 'Shared',
       ackTimeoutMs: 10000,
     })
     // Receive messages
     for (let i = 0; i < 10; i += 1) {
       const msg = await consumer.receive()
       console.log(msg.getData().toString())
       await consumer.acknowledge(msg)
     }
     await consumer.close()
     await client.close()
   })()
   
5. Create a Node.js producer and use the Node.js producer to produce messages.
   const Pulsar = require('pulsar-client')
   const issuer_url = process.env.ISSUER_URL
   const private_key = process.env.PRIVATE_KEY
   const audience = process.env.AUDIENCE
   const scope = process.env.SCOPE
   const service_url = process.env.SERVICE_URL
   const client_id = process.env.CLIENT_ID
   const client_secret = process.env.CLIENT_SECRET
   
   ;(async () => {
     const params = {
       issuer_url: 'your-issuer-url',
     }
     if (private_key.length > 0) {
       params['private_key'] = 'file:///path/to/private-key-file.json'
     } else {
       params['client_id'] = 'your-client-id'
       params['client_secret'] = 'your-client-secret'
     }
     if (audience.length > 0) {
       params['audience'] = 'your-audience'
     }
     if (scope.length > 0) {
       params['scope'] = 'your-scope'
     }
     const auth = new Pulsar.AuthenticationOauth2(params)
   
     const producer = await client.createProducer({
       topic: 'your-topic',
       sendTimeoutMs: 30000,
       batchingEnabled: true,
     })
     // Send messages
     for (let i = 0; i < 10; i += 1) {
       const msg = `my-message-${i}`
       producer.send({
         data: Buffer.from(msg),
       })
       console.log(`Sent message: ${msg}`)
     }
     await producer.flush()
     await producer.close()
     await client.close()
   })()