Lambda-api-router NPM

Lamb Chop

Lamb Chop provides an elegant and expressive syntax for using a single Lambda function as a proxy service for API Gateway routes. Write serverless code in a server oriented manner.

Getting Started

Before you can use this service make sure you setup your AWS API Gateway as a proxy service. You can create a single route which accepts any http request and path using the special /{path+}. Please see this AWS document for more information on setting up your lambda function as a proxy service.

Installing

You can install this package through NPM with

npm i --save lambda-api-router

Check out the following example for using the service in a live system:

const Api = require('lambda-api-router');
const app = new Api();

app.get('/foo/bar', (req, res) => {
    res.json({ success: true, test: 'Its working!', response: response.substring(0, 21) });
});

app.post('/foo/bar', (req, res) => {
    // ...
});

app.put('/users/find', (req, res) => {
    // ...
});

app.delete('/user/:id', (req, res) => {
    // ...
});

exports.handler = async (event, context) => app.listen(event, context);

Async Actions

You can also use asynchronous actions and promises within your route handlers:

const Api = require('lambda-api-router');
const request = require('request-promise-native');

const app = new Api();

app.get('/foo/bar', async (req, res) => {
    const response = await request('http://google.com');
    res.json({ success: true, response: response.substring(0, 21) });
});

exports.handler = (event, context) => app.listen(event, context);

Query & Request Params

You can easily access query and request parameters through req.query and req.params respectively.

const Api = require('lamb-chop');

const app = new Api();

app.get('/foo/bar', (req, res) => {
    res.json({ query: req.query, params: req.params });
});

exports.handler = (event, context) => app.listen(event, context);

Set Response Status & Headers

You can easily access query and request parameters through req.query and req.params respectively.

const Api = require('lambda-api-router');

const app = new Api();

app.get('/foo/bar', (req, res) => {
    const headers = { 
        Accept: 'application/json',
        'Content-Type': 'application/json'
    };
   
    res.headers(headers)
       .status(200)
       .json({ query: req.query, params: req.params });
});

exports.handler = (event, context) => app.listen(event, context);

Set Response Status & Headers

You can also add middleware to your routes. Middleware is simply a function which has access to the request and response objects which execute before the actual route handler is executed. Middleware is useful for things like checking authentication, adding headers, logging and other common web tasks.

You can register middleware using the use function like so:

const Api = require('lambda-api-router');
const jwt = require('jsonwebtoken');

const app = new Api();

// Logging Middleware
app.use((req, res) => {
    console.log(`[${req.httpMethod}] -- ${req.path} --`);
});

// Custom header Middleware
app.use((req, res) => {
    res.headers({
       'X-Custom-Header': 'my-custom-value', 
    });
});

// Authentication Middleware
app.use((req, res) => {
    const token = req.body.token;
    jwt.verify(token, 'shhhhh', function(err, decoded) {
        console.log(decoded.foo) // bar
        // if decoded.foo => proceed with request
        // else return res.error({ ... });
    });
});

app.get('/foo/bar', (req, res) => {
    const headers = { 
        Accept: 'application/json',
        'Content-Type': 'application/json'
    };
   
    res.headers(headers)
       .status(200)
       .json({ query: req.query, params: req.params });
});

exports.handler = (event, context) => app.listen(event, context);