Learn about what a serverless architecture is, why they are growing in popularity, and who the key players are in a serverless API build on the AWS platform. Then get started building your own servless API!

1. MAKE NEXT POSSIBLE Ⓡ
Kenzan Providence Hack Nights
October 26th, 2017
Serverless Architectures in Modern
Applications

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What Are Serverless Architectures?
They are not actually “serverless”...
Instead, serverless architectures remove the need for managing and handling
the servers where the application or services run.
Server management is handled by third parties for you!

3. 3
What Are Serverless Architectures?
They are not actually “serverless”...
Instead, serverless architectures remove the need for managing and handling
the servers where the application or services run.
Server management is handled by third parties for you!

4. The Benefits of Serverless
Serverless architectures have a lot of upside, not least of which is $$ saved.
No Server Maintenance Flexible Scaling
High Availability No Idle Capacity
Lambda Costs vs EC2: https://www.trek10.com/blog/lambda-cost/

5. The Current Shortcomings of Serverless
Serverless architectures are still new, and there are some growing pains.
Limited Execution
Duration
Statelessness
Limited Run-Time
Support
Cold Start Time
Logging & Debugging

6. When Does a Serverless
API Make Sense?
A serverless API is a good choice when you
want low server maintenance and low cost, with
a microservice application of moderate security,
that is not exceptionally sensitive to latency.

7. How Do Serverless
Architectures Work?
Let’s go over the key components of a serverless
architecture, AWS style.
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8. The Overall View

9. Route 53 is a DNS service that allows you to assign a
custom domain name to your web IP address.
This is an optional piece of the serverless configuration but
is commonly used.
API gateway assigns a default route to your API that can be
used without extra configuration.
We won’t be using this in our example today but it is an
important AWS service to know about.
Route 53
The Resource Router

10. AWS API Gateway is integral to designing a serverless web
API.
A series of configuration that handling API routing and
Lambda execution. Can be configured with a
swagger.yaml file.
The API Gateway performs a series of tasks:
- Authorizes incoming requests
- Routes incoming requests
- Formats responses into HTTP response format for
consumption by the client
- Handles errors responses from the Lambda functions
AWS API Gateway
The Gatekeeper/Router to the Microservices

11. Without access to your servers, you must secure your
resources through IAM policies both at the API Gateway
level and the Lambda level.
Many options to secure traffic including:
- JWT tokens
- IP Address
- Headers
- Cookies
API Gateway allows for custom, dynamically generated IAM
policies provided by custom authorizers.
AWS Identity Access Management (IAM)
The Security Around the Gateway

12. The basic component of Function-as-a-Service (F.a.a.S)
architecture.
Lambdas are the holding place and configuration for code
that will be executed in any one of many servers in the cloud.
Can be configured with unique IAM roles, environment
variables, memory, timeout, and more.
Currently support the following runtime environments :
- Node.js 6.10, Edge Node.js 4.3, Node.js 4.3
- C#
- Java 8
- Python 3.6 & 2.7
AWS Lambda Functions
The Serverless Functions Where the Code is Run

13. AWS DynamoDB is a No-SQL database that is commonly
paired with serverless frameworks because of it’s similar
benefits :
- Fast & Consistent Performance
- Highly Scalable
- Fully Managed
- Event Driven Programming (Integrates with Lambda
function to process DB events)
- Flexible
- Integrates with IAM for security and access control
We will not be using this in our example today but it is a
good technology to know about.
AWS DynamoDB
The Database Layer

14. DIY Serverless Framework
Let’s get started building our own serverless web
API!
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Step 1: Download the Repository
This is going to be our client code, server code, and configuration. This is the jumping off point for
our serverless web API.
Repository URL
www.github.com/mschmidt712/serverless-counter
Repository Holder Username: mschmidt712
Repository Name: serverless-counter

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Step 2: Install Dependencies and Run UI
Here we will get the UI for our application up and running. This is going to be a simple web
application that allows the user to increment and decrement a counter.
Install Dependencies
yarn install or npm install
Run UI
npm start

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Step 3: Sign in to AWS Console
Immediately, the application is configured to run off of a pre-made serverless backend. Let’s start
the process of building our own to hook up to.

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Step 4: Create the Lambda Functions
To speed up the process of building the backend, the code for each lambda function is located in the
serverless-counter repository under the server folder

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Step 5: Create the API Gateway
The suggested route to configure the API gateway is using a swagger.yaml file. For this exercise
we will use the swaggerWithApiGatewayExtensions.yaml file to save some configuration time.

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Step 6: Configure the API Gateway
As you will see, the API Gateway requires a large amount of configuration. We’ll walk through that
now.

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Step 7: Deploy Your API
Once the configuration is done your API is ready to deploy!

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Step 8: Connect Your API to Your Counter
Now that your API is deployed, you will be given a unique url to access it. Copy/Paste this url into the
appConfig.json file in the UI and watch your API go live.

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Questions?
Resources
Introduction to Serverless Computing with AWS Lambda:
https://www.contino.io/files/Contino-Introduction-to-Serverless-
Computing-with-AWS-Lambda.pdf
Amazon Docs for Lambdas: https://aws.amazon.com/lambda/
Amazon Docs for API Gateway: https://aws.amazon.com/api-
gateway/
Serverless Framework: https://serverless.com/
How to Build a Serverless API with AWS API Gateway (python):
https://www.twilio.com/blog/2017/06/build-serverless-api-
amazon-web-services-api-gateway.html
Serverless Architectures (denser informational blog):
https://martinfowler.com/articles/serverless.html

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Backup Slides

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Step 4: Create the Lambda Functions
Uploading the Lambda Code.

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Step 4: Create the Lambda Functions
Configuring the Lambda function.

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Step 4: Create the Lambda Functions
Testing the Lambda function after creation.

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Step 6: Configure the API Gateway
Configuration of the Method Request.

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Step 6: Configure the API Gateway
Configuration of the Integration Request.

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Step 6: Configure the API Gateway
Configuration of the Integration Response.

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Step 6: Configure the API Gateway
Configuration of the Method Response.

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Step 7: Deploy Your API
Creating the deployment stage for the API.