Very Lightweight framework for serverless APIs

The UMD serverless router is a lightweight framework for AWS API Gateway+Lambda. It has minimal dependencies, supports both callback and async+await and does not mask errors as success, so CloudWatch metrics shows accurate error counts for lambda invocations.

Example

# index.js

const APIROUTER = require ('umd-serverless-router');

const PEOPLE = require ('./lib/people');

/* Saved outside of the lambda entrypoint for cold start re-use/optimization. */
let apiRouter;


module.exports.routeProcessorLambdaEntrypoint = async (event, context) => {
    if ( !apiRouter ) {
        apiRouter = new APIROUTER ();

        let people = new PEOPLE ();
        apiRouter.registerRoutes ({
            'setupFunction': people.routeSetup.bind (people),
            'prefix':        'v1/people',
        });
    }

    return await apiRouter.routeRequests (event, context);
};



# lib/people.js

let people = function ()
{
}

# setup routes for the people service
people.prototype.routeSetup = function (apiRouter, params)
{
    /* GET /v1/people */
    apiRouter.addRoute ({
        'method':  'GET',
        'path':    '',
        'handler': self.listPeople.bind (self),
    });

    /* POST /v1/people/${personId} */
    apiRouter.addRoute ({
        'method':  'POST',
        'path':    '{personId}',
        'handler': self.addPerson.bind (self),
    });
};


people.prototype.listPeople = function (request)
{
    return new Promise ((resolve, reject) => {
        return resolve ([
            {
                'name': 'homer',
                'age':  42,
            },
            {
                'name': 'marge',
                'age':  41,
            },
        ]);
    });
};

module.exports = people;

References

Request Object Details

{
  "version": "2.0",
  "routeKey": "GET /{proxy+}",
  "rawPath": "/v1/people",
  "rawQueryString": "",
  "headers": {
      "accept": "*\/*",
      "access-control-request-method": "GET",
      "authorization": "Bearer SECRET_JWT",
      "content-length": "0",
      "host": "abcdefg.execute-api.us-east-1.amazonaws.com",
      "origin": "http://localhost:8080",
      "user-agent": "curl/7.19.6 (x86_64-unknown-linux-gnu) ...",
      "x-amzn-trace-id": "Root=1-61645450-ABCDEFG",
      "x-forwarded-for": "127.0.0.1",
      "x-forwarded-port": "443",
      "x-forwarded-proto": "https"
  },
  "requestContext": {
      "accountId": "123456789012",
      "apiId": "abcdefg1234",
      "authorizer": {
          "lambda": {
              "authInfo": {
                  "stuff": "returned",
                  "by the": "authorizer"
              }
          }
      },
      "domainName": "abcdefg.execute-api.us-east-1.amazonaws.com",
      "domainPrefix": "abcdefg",
      "http": {
          "method": "GET",
          "path": "/v1/people",
          "protocol": "HTTP/1.1",
          "sourceIp": "127.0.0.1",
          "userAgent": "curl/7.19.6 (x86_64-unknown-linux-gnu) ...",
      },
      "requestId": "ABCEDFGHIJ=",
      "routeKey": "GET /{proxy+}",
      "stage": "$default",
      "time": "11/Oct/2021:15:12:16 +0000",
      "timeEpoch": 1633965136901
  },
  "pathParameters": {
      "proxy": "v1/people"
  },
  "body": "{ \"This\": \"is a request body\", \"a\": 3 }",
  "isBase64Encoded": false
}