tencent cloud

Overview

This document describes how to access CKafka to send/receive messages with the SDK for Node.js through SASL_PLAINTEXT over public network.

Prerequisites

• Install GCC
• Install Node.js
• Configure an ACL policy
• Download demo

Directions

Step 1. Install the C++ dependent library

1. Run the following command to switch to the yum source configuration directory /etc/yum.repos.d/.

   cd /etc/yum.repos.d/
   

2. Create the yum source configuration file confluent.repo.

   [Confluent.dist]
   name=Confluent repository (dist)
   baseurl=https://packages.confluent.io/rpm/5.1/7
   gpgcheck=1
   gpgkey=https://packages.confluent.io/rpm/5.1/archive.key
   enabled=1   
   [Confluent]
   name=Confluent repository
   baseurl=https://packages.confluent.io/rpm/5.1
   gpgcheck=1
   gpgkey=https://packages.confluent.io/rpm/5.1/archive.key
   enabled=1
   

3. Run the following command to install the C++ dependent library.

   yum install librdkafka-devel
   

Step 2. Install the Node.js dependent library

1. Run the following command to specify the OpenSSL header file path for the preprocessor.

   export CPPFLAGS=-I/usr/local/opt/openssl/include
   

2. Run the following command to specify the OpenSSL library path for the connector.

   export LDFLAGS=-L/usr/local/opt/openssl/lib
   

3. Run the following command to install the Node.js dependent library.

   npm install i --unsafe-perm node-rdkafka
   

Step 3. Prepare configurations

Create the CKafka configuration file setting.js.

module.exports = {
  'sasl_plain_username': 'ckafka-xxxxxxx#ckafkademo',
  'sasl_plain_password': 'ckafkademo123',
  'bootstrap_servers': ["xxx.ckafka.tencentcloudmq.com:6018"],
  'topic_name': 'xxx',
  'group_id': 'xxx'
}

Parameter	Description
sasl_plain_username	Username in the format of instance ID + # + username. The instance ID can be obtained in Basic Info on the instance details page in the CKafka console, and the username is set when the user is created in User Management
sasl_plain_password	User password, which is set when the user is created in User Management on the instance details page in the CKafka console.
bootstrap_servers	SASL access point, which can be obtained in Basic Info > Access Mode on the instance details page in the CKafka console.
topic_name	Topic name, which can be created and obtained in Topic Management on the instance details page in the CKafka console.
group_id	Consumer group ID, which can be customized based on business requirements.

Step 4. Send messages

1. Write a message production program named producer.js.
   const Kafka = require('node-rdkafka');
   const config = require('./setting');
   console.log("features:" + Kafka.features);
   console.log(Kafka.librdkafkaVersion);
    var producer = new Kafka.Producer({
       'api.version.request': 'true',
       'bootstrap.servers': config['bootstrap_servers'],
       'dr_cb': true,
       'dr_msg_cb': true,
       'security.protocol' : 'SASL_PLAINTEXT',
       'sasl.mechanisms' : 'PLAIN',
       'sasl.username' : config['sasl_plain_username'],
       'sasl.password' : config['sasl_plain_password']
   });
    var connected = false
    producer.setPollInterval(100);
    producer.connect();
    producer.on('ready', function() {
   connected = true
   console.log("connect ok")
    });
    function produce() {
   try {
       producer.produce(
       config['topic_name'],
       new Buffer('Hello CKafka SASL'),
       null,
       Date.now()
       );
   } catch (err) {
       console.error('Error occurred when sending message(s)');
       console.error(err);
   }
   }
    producer.on("disconnected", function() {
   connected = false;
   producer.connect();
   })
    producer.on('event.log', function(event) {
       console.log("event.log", event);
   });
    producer.on("error", function(error) {
       console.log("error:" + error);
   });
    producer.on('delivery-report', function(err, report) {
       console.log("delivery-report: producer ok");
   });
   // Any errors we encounter, including connection errors
   producer.on('event.error', function(err) {
       console.error('event.error:' + err);
   })
    setInterval(produce,1000,"Interval");

2. Execute the following command to send messages.

   node producer.js
   

3. View the execution result.
   

4. On the Topic Management tab page on the instance details page in the CKafka console, select the target topic, and click More > Message Query to view the message just sent.
   

Step 5. Subscribe to messages

1. Create a message consumption program named consumer.js.
   consumer.on('event.log', function(event) {
      console.log("event.log", event);
   });
   consumer.on('error', function(error) {
      console.log("error:" + error);
   });
   consumer.on('event', function(event) {
          console.log("event:" + event);
   });const Kafka = require('node-rdkafka');
   const config = require('./setting');
   console.log(Kafka.features);
   console.log(Kafka.librdkafkaVersion);
   console.log(config)
   var consumer = new Kafka.KafkaConsumer({
      'api.version.request': 'true',
      'bootstrap.servers': config['bootstrap_servers'],
      'security.protocol' : 'SASL_PLAINTEXT',
      'sasl.mechanisms' : 'PLAIN',
      'message.max.bytes': 32000,
      'fetch.message.max.bytes': 32000,
      'max.partition.fetch.bytes': 32000,
      'sasl.username' : config['sasl_plain_username'],
      'sasl.password' : config['sasl_plain_password'],
      'group.id' : config['group_id']
   });
   consumer.connect();
   consumer.on('ready', function() {
   console.log("connect ok");
   consumer.subscribe([config['topic_name']]);
   consumer.consume();
   })
   consumer.on('data', function(data) {
   console.log(data);
   });
   consumer.on('event.log', function(event) {
      console.log("event.log", event);
   });
   consumer.on('error', function(error) {
      console.log("error:" + error);
   });
   consumer.on('event', function(event) {
          console.log("event:" + event);
   });

2. Execute the following command to send messages.

   node consumer.js
   

3. View the execution result.
   

4. On the Consumer Group tab page on the instance details page in the CKafka console, select the corresponding consumer group name, enter the topic name, and click Query Details to view the consumption details.