Monday, February 27, 2017

AWS Step Functions

Step function is a new AWS service. AWS Step Functions makes it easy to coordinate the components of distributed applications and microservices using visual workflows. Building applications from individual components that each perform a discrete function lets you scale and change applications quickly. Step Functions is a reliable way to coordinate components and step through the functions of your application. Step Functions provides a graphical console to arrange and visualize the components of your application as a series of steps. This makes it simple to build and run multi-step applications. Step Functions automatically triggers and tracks each step, and retries when there are errors, so your application executes in order and as expected. Step Functions logs the state of each step, so when things do go wrong, you can diagnose and debug problems quickly. You can change and add steps without even writing code, so you can easily evolve your application and innovate faster.

AWS Step Functions manages the operations and underlying infrastructure for you to help ensure your application is available at any scale.

With regards to pricing you only pay for the transitions, that is the steps between tasks.

Friday, February 17, 2017

Custom Authorization HTTP Request in AWS NodeJS Lambda function

Below is the sample code for AWS NodeJS lambda function. This will show how to make an HTTP request with Custom Authorization using "request" node module.
request v2.79.0 - Simplified HTTP request client.
Request package is designed to be the simplest way possible to make http calls. It supports HTTPS and follows redirects by default.

/// Module to test HTTP POST Request
/// Created By: Sohan Fegade
/// Created Date: 17-Feb-2017

var request = require('request');
var buffer = require('buffer');

console.log('Loading http-test-module');

exports.handler = function (event, context, callback) {

    if (event != null) {
        console.log('event = ' + JSON.stringify(event));

        var username = 'sampleuser';
        var password = 'samplepassword';
       
        var auth = 'Basic ' + buffer.Buffer(username + ':' + password).toString('base64');
       
        var options = {
            url: 'https://www.sample-auth-url.com/oauth/token',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': auth
            },
            json: {
                'type': 'test',
                'input': 'test',
                'field': 'test',
                'scope': 'urn:scope-api',
                'token-type': 'auth-token'
            }
        }

        request.post(options, function (error, response, body) {
            if (!error && response.statusCode === 200) {
               console.log('Access Token : ' + body.access-token);
            }
               
            context.callbackWaitsForEmptyEventLoop = false;
            callback(null, 'SUCCESS');
       });
    }
    else {
        console.log('No event object');
    }
};