Module: Build a Multi-Region Serverless Application for Resilience and High Availability

In this workshop you will use Amazon API Gateway, AWS Lambda and Amazon DynamoDB to build a Customer Ticketing application so we can provide a great experience to Wild Rydes users.

The Wild Rydes team wants this application to meet the following requirements:

1. Users must be able to submit and view tickets through the ticketing application
2. Users must be able to log in with their Facebook user id
3. The application should use an entirely serverless architecture (we don't have an operations team to manage our infrastructure!)
4. The application must be able to failover to another region in the case of a disaster. The RTO and RPO must both be less than 15 minutes.
   • RTO: Recovery time objective – the targeted duration of time and a service level within which a business process must be restored after a disaster.
   • RPO: Recovery point objective – the maximum targeted period in which data might be lost from a service due to a major incident.

Architecture Overview

The application will utilize three layers:

1. A UI layer built using HTML, Javascript and CSS and hosted directly from AWS S3
2. An API layer built using Node.js running on AWS Lambda and exposed via Amazon API Gateway.
3. A data layer storing customer tickets in DynamoDB.

For the purposes of this workshop, our failover is focused on the path from our application (in this case, a web application) through API Gateway, Lambda and DynamoDB.

The backend components will be replicated to the second region so that we can failover in the event of a disaster. In addition, all data in DynamoDB will be replicated from the primary region to the secondary region ensuring that our application data will be available when we failover.

A few additional components will be utilized to assist us including AWS Cognito to allow the application to authenticate users and authorize access to the API layer. AWS Route53 will be used for DNS and will allow us to perform health checks on our primary region, and upon detecting an issue, automatically switching to our secondary region using Route53 DNS updates.

Implementation Instructions

This workshop is broken up into multiple modules. In each, we will walk through a high level overview of how to implement or test a part of this architecture. You will expand sections for detailed command or console instructions.

Region Selection

We will be using the following two regions for this workshop. Please remember these and check before creating resources to ensure you are in the correct region:

• Primary: eu-west-1 (Ireland)
• Secondary: ap-southeast-1 (Singapore)

Using the two regions above for this workshop is mandatory. We will start with eu-west-1 (Ireland) and then ap-southeast-1 (Singapore).

Modules

0. Create AWS Cloud9 Environment
1. Build an API layer
2. Build a UI layer
3. Replicate to a second region
4. Test failover
5. Cleaning Up
6. Optional Lab - S3 Cross Region Replication and CloudFront Custom Domain

Prerequisites

(please read these carefully and do not jump ahead and start setting things up unless specifically called out)

AWS Account

In order to complete this workshop you'll need an AWS Account with access to create AWS IAM, S3, DynamoDB, Lambda and API Gateway. The code and instructions in this workshop assume only one student is using a given AWS account at a time. If you try sharing an account with another student, you'll run into naming conflicts for certain resources - we do not recommend this as there may be unpredictable results or difficult to identify configuration issues.

Domain Name (this is covered in Module 3)

You will also need to either purchase a domain (Purchase it now before you start the lab as it takes a while), or repurpose an existing unused domain you already own. You will need to delegate DNS to Route53 if the domain is not already acquired through AWS. You may also need access to the email account associated with the domain name registration.

Facebook Developer Account and App ID

Our application requires a Facebook federated identity to allow users to login with an existing account. In order to set this up you will need a Facebook Developer account. You may set up the account now, but do not start configuring anything else yet.

You can sign up using this link.

Note that you will create the App ID later on in this guide using the website URL you will set up in Module 2.

Important Note

If your laptop's security policy blocks Facebook or any 3rd party cookies (required by Cloud9), pair up with someone else who has a laptop which is not blocked. Please use only Chrome or Firefox browsers.

AWS Cloud9 for AWS Command Line Interface

To complete parts of this workshop you'll need the AWS Command Line Interface (CLI). The front end application is written in AngularJS and requires node and npm. To avoid spending time on configuring your laptop, we will use AWS Cloud9 as our IDE. It has AWS CLI preconfigured.

Follow the instruction here to launch a AWS Cloud9 IDE before we start the lab. Once you have AWS Cloud9 and nodejs installed, you can start the lab.