kafka-producer-js/src/config.js

A configurable Kafka producer package for Node.js applications with NFL event examples and AWS MSK integration

/**
 * Kafka Configuration Module
 * Handles connection configuration for Kafka producer
 */

const { Partitioners } = require('kafkajs');

class KafkaConfig {
  constructor(config = {}) {
    this.validateConfig(config);
    this.config = this.buildConfig(config);
  }

  /**
   * Validates the required configuration parameters
   * @param {Object} config - Configuration object
   */
  validateConfig(config) {
    if (!config.brokers || !Array.isArray(config.brokers) || config.brokers.length === 0) {
      throw new Error('brokers array is required and must contain at least one broker');
    }

    config.brokers.forEach((broker, index) => {
      if (typeof broker !== 'string' || !broker.trim()) {
        throw new Error(`Invalid broker at index ${index}. Must be a non-empty string`);
      }
    });
  }

  /**
   * Builds the complete Kafka configuration
   * @param {Object} config - User provided configuration
   * @returns {Object} Complete Kafka configuration
   */
  buildConfig(config) {
    const defaultConfig = {
      ssl: true,
      retry: {
        initialRetryTime: 100,
        retries: 8
      }
    };

    return {
      ...defaultConfig,
      ...config,
      brokers: config.brokers,
      // Merge retry configuration if provided
      retry: config.retry ? { ...defaultConfig.retry, ...config.retry } : defaultConfig.retry
    };
  }

  /**
   * Gets the Kafka configuration
   * @returns {Object} Kafka configuration
   */
  getConfig() {
    return this.config;
  }

  /**
   * Gets producer specific configuration
   * @returns {Object} Producer configuration
   */
  getProducerConfig() {
    const defaultProducerConfig = {
      maxInFlightRequests: 1,
      idempotent: false,
      transactionTimeout: 30000,
      allowAutoTopicCreation: true,
      createPartitioner: Partitioners.LegacyPartitioner
    };

    return {
      ...defaultProducerConfig,
      ...(this.config.producer || {})
    };
  }
}

module.exports = KafkaConfig;