qapinterface/lib/logging/logger-creator.js

Comprehensive API utilities for Node.js applications including authentication, security, request processing, and response handling with zero external dependencies

/**
 * Logger Creator
 * Single Responsibility: Create logger instances ONLY
 */

const pino = require('pino');
const fs = require('fs');
const path = require('path');
const { 
  LOG_LEVELS, 
  NODE_ENV, 
  CLOUDWATCH_LOG_GROUP, 
  CLOUDWATCH_LOG_STREAM, 
  AWS_REGION, 
  AWS_ACCESS_KEY_ID, 
  AWS_SECRET_ACCESS_KEY 
} = require('../../config/localVars');

// Singleton logger instance
let logger = null;

/**
 * Creates and returns a singleton logger instance.
 * @param {object} [options] - Pino logger options.
 * @returns {pino.Logger} - A Pino logger instance.
 */
async function createLogger(options = {}) {
  if (logger) {
    return logger;
  }

  const {
    logFilePath = './logs/app.log',
    level = LOG_LEVELS.INFO,
    prettyPrint = NODE_ENV !== 'production',
  } = options;

  const logDir = path.dirname(logFilePath);
  try {
    await fs.promises.access(logDir);
  } catch (err) {
    if (err.code === 'ENOENT') {
      await fs.promises.mkdir(logDir, { recursive: true });
    } else {
      throw err;
    }
  }

  // Build transport targets array
  const targets = [
    {
      target: 'pino-roll',
      options: {
        file: logFilePath,
        frequency: 'daily',
        size: '10m',
        mkdir: true,
      },
      level: level,
    }
  ];

  // Add pretty print in non-production
  if (prettyPrint) {
    targets.push({
      target: 'pino-pretty',
      options: {
        colorize: true,
        translateTime: 'SYS:standard',
        ignore: 'pid,hostname',
      },
      level: level,
    });
  }

  // Add CloudWatch in production
  if (NODE_ENV === 'production') {
    targets.push({
      target: 'pino-cloudwatch',
      options: {
        group: CLOUDWATCH_LOG_GROUP || 'qapi-logs',
        stream: CLOUDWATCH_LOG_STREAM || 'app',
        aws_region: AWS_REGION || 'us-west-2',
        aws_access_key_id: AWS_ACCESS_KEY_ID,
        aws_secret_access_key: AWS_SECRET_ACCESS_KEY,
      },
      level: level,
    });
  }

  const transport = pino.transport({ targets });
  logger = pino(transport);

  // Add graceful shutdown hooks
  process.on('beforeExit', () => logger.flush());
  process.on('SIGINT', () => {
    logger.flush();
    process.exit(0);
  });

  return logger;
}

module.exports = {
  createLogger
};