logs-interceptor/preload.js

High-performance, production-ready log interceptor for Node.js applications with Loki integration

/**
 * Preload script for automatic initialization of logs-interceptor
 * 
 * Usage:
 * NODE_OPTIONS="--require logs-interceptor/preload" \
 * LOGS_INTERCEPTOR_URL="http://localhost:3100/loki/api/v1/push" \
 * LOGS_INTERCEPTOR_TENANT_ID="tenant1" \
 * LOGS_INTERCEPTOR_APP_NAME="my-app" \
 * node app.js
 */

const { init, loadConfigFromEnv, validateConfig } = require('./dist/index.js');

try {
  // Load configuration from environment
  const envConfig = loadConfigFromEnv();
  
  // Only initialize if we have required config and it's not explicitly disabled
  if (
    envConfig.transport?.url && 
    envConfig.transport?.tenantId && 
    envConfig.appName &&
    process.env.LOGS_INTERCEPTOR_ENABLED !== 'false'
  ) {
    // Validate configuration
    const errors = validateConfig(envConfig);
    if (errors.length > 0) {
      console.error('[logs-interceptor:preload] Configuration errors:', errors);
      process.exit(1);
    }
    
    // Initialize with console interception enabled by default
    init({
      ...envConfig,
      interceptConsole: true,
      debug: process.env.LOGS_INTERCEPTOR_DEBUG === 'true',
    });
    
    console.log('[logs-interceptor:preload] Initialized successfully');
  } else {
    console.log('[logs-interceptor:preload] Skipped - missing required configuration');
  }
} catch (error) {
  console.error('[logs-interceptor:preload] Initialization failed:', error.message);
  
  // Don't exit on error in preload - let the app continue
  if (process.env.LOGS_INTERCEPTOR_FAIL_ON_ERROR === 'true') {
    process.exit(1);
  }
}