Optimal Approach for Multi-Database Connections in Nitro Server?

[tberk]

Hello! I have been connecting to multiple databases using plugins, with each connection pool attached to the Nitro context. Here’s a sample of my setup:

export default defineNitroPlugin(async (nitroApp) => {
  const runtimeConfig = useRuntimeConfig();

  // MAIN Database Pool
  const pool = new PG.Pool({
    user: runtimeConfig.db.user,
    host: runtimeConfig.db.host.main,
    database: 'postgres',
    password: runtimeConfig.db.password,
    port: 5432,
    max: 250,
    ssl: true,
    statement_timeout: 3 * 60 * 1000,
    maxUses: 10000,
  });

  // ... other pools

  // Test connections
  try {
    await pool.query('SELECT NOW()');
    await pool_meta.query('SELECT NOW()');
  } catch (error) {
    console.error('🚨 Failed to connect to the database!');
    process.exit(1);
  }

  // Attach pools and Redis to request context
  nitroApp.hooks.hook('request', (event) => {
    event.context.pools = {
      main: pool,
      meta: pool_meta,
      // ... other pools
    };
    event.context.redis = redis;
  });

  // Handle graceful shutdown
  nitroApp.hooks.hook('close', async () => {
    console.log('-> Shutting down PG pools.');
    await pool.end();
    await pool_meta.end();
    console.log('-> Shutting down Redis.');
    await redis.quit();
  });
});

This setup mostly works, but I occasionally encounter errors like "Cannot read properties of undefined (reading 'main')". I suspect it could be due to how the context is initialized or the way I’m attaching pools to requests.

Is there a better way to handle multi-database connections in Nitro, or a way to prevent this error? Any insights would be appreciated! Thanks!