Intro to AWS

[Advanced] - AWS Intro, Set up AWS and Serverless, Lambda, API Gateway

What is AWS?

Amazon Web Services(AWS) is a platform of cloud computing which provides a simple way to access servers, storage, databases and a broad set of applications. We are basically renting out AWS servers to host our application instead of having to maintain our own. There are many type of services in AWS, each performing a specific functionality.

Why use AWS?

Low Cost - As developers, we pay end up paying less if we want to host our application on AWS servers. Since AWS has many active users, it drives down the cost of server use.
Advanced security features - Expert security staff are continually upgrading and maintaining servers.
Highly reliable - your data is matained in many different data centers just in case one goes down

What is Serverless Framework?

AWS allows us to access the their platform through programmatic access or AWS management console access. In this course, we will be using programmatic access through the Serverless Framework which allows us to access AWS through the command line and code editor.

What is AWS Lambda?

An AWS service that allows developers to run code without having to manage a server. No express server needed. A Lambda is basically a function in the cloud.

What is API Gateway?

An AWS service that enables developers to create, publish, maintain, monitor, and secure APIs at any scale. You can create APIs that access AWS or other web services, as well as data stored in the AWS Cloud. It allows developers to create CRUD routes(GET, POST, PUT, DELETE).

What does deploy mean?

Moving our application to the AWS cloud/servers. In our case, we will be deploying our Lambda function.

What will we be doing?

We will conifgure our AWS credentials and Serverless credentials, then will set up our Lambda function and API Gateway to deploy a GET url enpoint for our frontend client.

Configuring AWS and Serverless

Your instructor should have provided you with a Access Key ID and a Secret Access Key. Please save them in a safe location.
Open up your git-bash terminal
Install aws-cli for windows
- Install AWS Command Line
Configure Access_ID, Secrect_Access_id, and region on our computer
- Type aws configure then hit enter
  - Input the following
    - access_id
    - access_secret_id
    - region: us-west-2
npm install Serveless Framework npm install -g serverless
Set Serverless provider credentials

serverless config credentials --provider aws --key YOUR_ACCESS_KEY --secret YOUR_SECRET_KEY

Create Serverless Template and Lambda Function

Create a new directory/projectmkdir YOUR_PROJECT_NAME
CD into your directory/project cd YOUR_PROJECT_NAME
Create boilerplate/template to use Serverless**

serverless create --template aws-nodejs

Change service name in serverless.yml file
Uncomment the following:*

stage: dev
region: us-east-1

Then set region to us-west-2

Deploy your code

serverlesss deploy

Invoke deployed function

serverless invoke -f FUNCTION_NAME

Change message in lambda function then redeploy function only

serverless deploy -f FUNCTION_NAME

Invoke deployed function

serverless invoke -f FUNCTION_NAME

Get logs from deployed function

serverless logs -f FUNCTION_NAME -t

If need help with serverless commands

serverless --help

Create API Gateway GET request

Paste in the following code snippet in serverless.yml

functions:
  FUNCTION_NAME:
    handler: handler.FUNCTION_NAME
    events:
      - http:
          path: PATH_NAME
          method: get
          cors: true

Paste in the following in your response object, above the body property

This allows CORS

headers: {
     'Access-Control-Allow-Origin': '*',
     'Access-Control-Allow-Credentials': true
   },

Deploy your code

serverless deploy

You should see a GET endpoint url under endpoints:

Serverless Workflow

Write your functions
Useserverless deployonly when you've made changes toserverless.yml
Useserverless deploy function -f FUNCTION_NAMEto rapidly deploy changes when you are working on a specific AWS Lambda Function.
Useserverless invoke -f FUNCTION_NAMEto test your AWS Lambda Functions on AWS.
Open up a separate tab in your console and stream logs in there viaserverless logs -f FUNCTION_NAME -t.

Class Exercise

In your Lambda function, create a random food generator
Create file structure in your root path for you frontend

serverless-demo
|
+ --public
    |
    +-- index.html
    +-- styles.css
    +-- app.js

Use axios in your app.js to get a random food from your newly created GET endpoint
Render the following to your browser Today, I will eat a ${INSERT_FOOD_VALUE}
Your browser should render a different food everytime you refresh