Koa Framework

Koa is a Node.js middleware framework that is minimal and expressive in nature, and enables you to build robust web applications and APIs. Koa uses async functions that remove the need for callbacks, handles errors efficiently, and substantially reduces your time in building servers through a multitude of other features it offers.

This example illustrates the steps to build a simple Node.js app with the Koa framework. This application will then be bundled and associated with an AppSail service, and deployed to the console.

1. Create a new folder in your local system for the Koa app.

2. Navigate to the directory from your terminal and initialize Node with the following command:

    

        
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         npm init
    

Follow the steps in the terminal and provide the required details.

3. Add the Koa module to your application using npm by executing the command:

    

        
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         npm install --save koa
npm install --save @koa/router
    

4. You can now add the logic you require in the application’s code in the main file. Given below is a sample code for a basic “Hello World” program.

    

        
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         var Koa = require('koa');
var Router = require('@koa/router');

const app = new Koa();
const router = new Router();

router.get('/', (ctx, next) => {
    ctx.body = "Hello World"
});

app.use(router.routes())


app.listen(process.env.X_ZOHO_CATALYST_LISTEN_PORT | 9000);
    

5. You can now initialize an AppSail service in the same directory from the CLI or add it in an existing project directory. The app’s source must be your application’s directory. Provide the following value while initializing the app service:

   Stack: Node16

6. Ensure the main file, configuration files, and the node modules are present in the build directory you specify during initialization. Catalyst will automatically ZIP your app files during deployment to the remote console.

7. Deploy the app service to the console.

8. You can then configure the startup command given below from the console:

    

        
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         node index.js
    

You can also configure this in the app-config.json file before deploying.

Access the deployed app service from its endpoint URL.