koatty_serverless

Serverless adapter for Koatty framework - deploy to AWS Lambda, Alibaba Cloud FC, Tencent SCF.

Installation

npm install koatty_serverless

For AWS Lambda, also install the optional dependency:

npm install @codegenie/serverless-express

Quick Start

AWS Lambda

// src/lambda.ts
import { createHandler } from 'koatty_serverless';
import { App } from './App';

export const handler = createHandler(App, {
  platform: 'aws',
  healthCheck: async (app) => {
    // Check database connections after Lambda thaw
    // const ds = IOC.get('TypeormStore')?.getDataSource();
    // if (ds && !ds.isInitialized) await ds.initialize();
  },
  eventHandlers: {
    scheduled: async (event, context, app) => {
      // Handle CloudWatch scheduled events
      return { statusCode: 200 };
    },
  },
});

Alibaba Cloud Function Compute (FC)

// src/fc.ts
import { createHandler } from 'koatty_serverless';
import { App } from './App';

export const handler = createHandler(App, { platform: 'alicloud' });

Tencent Cloud SCF

// src/scf.ts
import { createHandler } from 'koatty_serverless';
import { App } from './App';

export const handler = createHandler(App, { platform: 'tencent' });

Without koatty-serverless

For platforms like Alibaba Cloud FC HTTP trigger where the input is already a standard HTTP object:

// src/handler.ts
import { createApplication } from 'koatty';
import { App } from './App';

let handler: (req: any, res: any) => Promise<any>;

export async function httpHandler(req: any, resp: any, context: any) {
  if (!handler) {
    const app = await createApplication(App);
    handler = app.getRequestHandler();
  }
  return handler(req, resp);
}

API Reference

createHandler(AppClass, options?)

Creates a serverless handler function.

Parameters:

• AppClass - Your Koatty application class
• options - Configuration options

Options:

| Option | Type | Default | Description | |--------|------|---------|-------------| | platform | 'aws' \| 'alicloud' \| 'tencent' | 'aws' | Target cloud platform | | adapter | ServerlessAdapter | - | Custom adapter (overrides platform) | | bootFunc | Function | - | Custom bootstrap function | | eventHandlers | Record<string, EventHandler> | - | Non-HTTP event handlers | | healthCheck | (app) => Promise<void> | - | Health check before each invocation |

EventHandler

type EventHandler = (
  event: any,
  context: any,
  app: KoattyApplication,
) => Promise<any>;

ServerlessAdapter Interface

interface ServerlessAdapter {
  readonly name: string;
  createHandler(app: KoattyApplication): (...args: any[]) => Promise<any>;
}

Custom Adapters

Implement ServerlessAdapter for other platforms:

import type { ServerlessAdapter } from 'koatty_serverless';
import type { KoattyApplication } from 'koatty_core';

class CloudflareAdapter implements ServerlessAdapter {
  readonly name = 'cloudflare-workers';

  createHandler(app: KoattyApplication) {
    const httpHandler = app.getRequestHandler();
    return async (request: Request) => {
      // Convert Cloudflare Request to Node.js HTTP format
      // ...
    };
  }
}

// Usage
export const handler = createHandler(App, {
  adapter: new CloudflareAdapter(),
});

License

BSD-3-Clause