Building your first Fullstack Serverless App with AWS Amplify

In this workshop we'll learn how to build cloud-enabled web applications with Angular & AWS Amplify.

Topics we'll be covering:

• Authentication
• GraphQL API with AWS AppSync
• Hosting
• Multiple Environments
• Deploying via the Amplify Console
• Removing / Deleting Services

Pre-requisites

• Node: 11.13.0. Visit Node
• npm: 6.9.0. Packaged with Node otherwise run upgrade

npm install -g npm

Getting Started - Creating the Application

To get started, we first need to create a new Angular project & change into the new directory using the Angular CLI.

If you already have it installed, skip to the next step. If not, either install the CLI & create the app or create a new app using:

npm install -g @angular/cli
ng new amplify-app

Now change into the new app directory and make sure it runs

cd amplify-app
npm install
ng serve

Changes to Angular CLI project

Add type definitions for Node by changing tsconfig.app.json. This is a requirement from aws-js-sdk.

{
  "compilerOptions": {
    "types": ["node"]
  },
}

Add the following code, to the top of src/polyfills.ts. This is a requirement for Angular 6+.

declare global {
  interface Window { 
    global: any; 
    process: any;
  }
}
window.global = window;
window.process = {};

Installing the CLI & Initializing a new AWS Amplify Project

Let's now install the AWS Amplify & AWS Amplify Angular libraries:

npm install --save aws-amplify aws-amplify-angular

Installing the AWS Amplify CLI

Next, we'll install the AWS Amplify CLI:

npm install -g @aws-amplify/cli

Now we need to configure the CLI with our credentials:

amplify configure

If you'd like to see a video walkthrough of this configuration process, click here.

Here we'll walk through the amplify configure setup. Once you've signed in to the AWS console, continue:

• Specify the AWS Region: ap-southeast-1(Singapore)
• Specify the username of the new IAM user: amplify-app

In the AWS Console, click Next: Permissions, Next: Tags, Next: Review, & Create User to create the new IAM user. Then, return to the command line & press Enter.

• Enter the access key of the newly created user:
  accessKeyId: (<YOUR_ACCESS_KEY_ID>)
  secretAccessKey: (<YOUR_SECRET_ACCESS_KEY>)
• Profile Name: default

To view the new created IAM User go to the dashboard at https://console.aws.amazon.com/iam/home#/users/. Also be sure that your region matches your selection.

Initializing A New Project

amplify init

• Enter a name for the project: amplify-app
• Enter a name for the environment: dev
• Choose your default editor: Visual Studio Code
• Please choose the type of app that you're building javascript
• What javascript framework are you using angular
• Source Directory Path: src
• Distribution Directory Path: dist/amplify-app
• Build Command: npm run-script build
• Start Command: ng serve
• Please choose the profile you want to use: default
• Do you want to use an AWS profile? Yes
• Please choose the profile you want to use default

Now, the AWS Amplify CLI has iniatilized a new project & you will see a new folder: amplify. The files in this folder hold your project configuration.

<amplify-app>
    |_ amplify
      |_ .config
      |_ #current-cloud-backend
      |_ backend
      team-provider-info.json

Adding Authentication

To add authentication, we can use the following command:

amplify add auth

When prompted choose

• Do you want to use default authentication and security configuration?: Default configuration
• How do you want users to be able to sign in when using your Cognito User Pool?: Username
• What attributes are required for signing up? (Press to select, to toggle all, to invert selection): Email

Now, we'll run the push command and the cloud resources will be created in our AWS account.

amplify push

To quickly check your newly created Cognito User Pool you can run

amplify status

To access the AWS Cognito Console at any time, go to the dashboard at https://console.aws.amazon.com/cognito/. Also be sure that your region is set correctly.

Configuring the Angular Application

Now, our resources are created & we can start using them!

The first thing we need to do is to configure our Angular application to be aware of our new AWS Amplify project. We can do this by referencing the auto-generated aws-exports.js file that is now in our src folder.

To configure the app, open main.ts and add the following code below the last import:

import Amplify from 'aws-amplify';
import amplify from './aws-exports';
Amplify.configure(amplify);

Now, our app is ready to start using our AWS services.

Importing the Angular Module

Add the Amplify Module and Service to src/app/app.module.ts:

import { AmplifyAngularModule, AmplifyService } from 'aws-amplify-angular';

@NgModule({
  imports: [
    AmplifyAngularModule
  ],
  providers: [
    AmplifyService
  ]
});

Using Amplify Service

The AmplifyService provides access to AWS Amplify core categories via Dependency Injection: auth, analytics, storage, api, cache, pubsub; and authentication state via Observables.

Using the Authenticator Component

AWS Amplify provides UI components that you can use in your App. Let's add these components to the project

npm i --save @aws-amplify/ui

Also include these imports to the top of styles.css

@import "~@aws-amplify/ui/src/Theme.css";
@import "~@aws-amplify/ui/src/Angular.css";

In order to use the Authenticator Component add it to src/app.component.html:

<amplify-authenticator></amplify-authenticator>

Now, we can run the app and see that an Authentication flow has been added in front of our App component. This flow gives users the ability to sign up & sign in.

To view any users that were created, go back to the Cognito dashboard at https://console.aws.amazon.com/cognito/. Also be sure that your region is set correctly.

Alternatively we can also use

amplify console auth

Accessing User Data

We can access the user's info now that they are signed in by calling currentAuthenticatedUser() which returns a Promise.

import { AmplifyService } from 'aws-amplify-angular';

@Component(...)
export class AppComponent {
  constructor(public amplify: AmplifyService) {
    amplify.auth().currentAuthenticatedUser().then(console.log)
  }
}

Custom authentication strategies

The Authenticator Component is a really easy way to get up and running with authentication, but in a real-world application we probably want more control over how our form looks & functions.

Let's look at how we might create our own authentication flow.

To get started, we would probably want to create input fields that would hold user input data in the state. For instance when signing up a new user, we would probably need 2 inputs to capture the user's email & password.

To do this, we could create a form like:

<form [formGroup]="signup" (ngSubmit)="onSignup(signup.value)">
  <div>
    <label>Email: </label>
    <input type="email" formControlName="email">
  </div>
  <div>
    <label>Password: </label>
    <input type="password" formControlName="password">
  </div>
  <button type="submit">Submit</button>
</form>

We'd also need to have a method that signed up & signed in users. We can us the Auth class to do this. The Auth class has over 30 methods including things like signUp, signIn, confirmSignUp, confirmSignIn, & forgotPassword. These functions return a promise so they need to be handled asynchronously.

import { Auth } from 'aws-amplify';

export class SignupComponent implements OnInit {
  public signup: FormGroup;

  constructor(
    private fb: FormBuilder,
  ) { }

  ngOnInit() {
    this.signup = this.fb.group({
      'email': ['', Validators.required],
      'password': ['', Validators.required]
    });
  }

  onSignup(value: any) {
    const email = value.email, password = value.password;
    Auth.signUp(email, password).then( _ => {
      this.success = true;
    }).catch(console.log);
  }

Adding a GraphQL API

To add a GraphQL API, we can use the following command:

amplify add api

Answer the following questions

• Please select from one of the below mentioned services GraphQL
• Provide API name: RestaurantAPI
• Choose an authorization type for the API API key
• Do you have an annotated GraphQL schema? No
• Do you want a guided schema creation? Yes
• What best describes your project: Single object with fields (e.g., “Todo” with ID, name, description)
• Do you want to edit the schema now? Yes

When prompted, update the schema to the following:

type Restaurant @model {
  id: ID!
  clientId: String
  name: String!
  description: String!
  city: String!
}

Next, let's push the configuration to our account:

amplify push

• Are you sure you want to continue? Yes
• Do you want to generate code for your newly created GraphQL API Yes
• Choose the code generation language target typescript
• Enter the file name pattern of graphql queries, mutations and subscriptions src/graphql/**/*.ts
• Do you want to generate/update all possible GraphQL operations - queries, mutations and subscriptions Yes
• Enter maximum statement depth [increase from default if your schema is deeply nested] 2
• Enter the file name for the generated code src/API.ts

Notice your GraphQL endpoint and API KEY.

This step created a new AWS AppSync API. Use the command below to access the AWS AppSync dashboard. Make sure that your region is correct.

amplify console api

• Please select from one of the below mentioned services GraphQL

Adding mutations from within the AWS AppSync Console

In the AWS AppSync console, on the left side click on Queries.

Execute the following mutation to create a new restaurant in the API:

mutation createRestaurant {
  createRestaurant(input: {
    name: "Nobu"
    description: "Great Sushi"
    city: "New York"
  }) {
    id name description city
  }
}

Now, let's query for the restaurant:

query listRestaurants {
  listRestaurants {
    items {
      id
      name
      description
      city
    }
  }
}

We can even add search / filter capabilities when querying:

query searchRestaurants {
  listRestaurants(filter: {
    city: {
      contains: "New York"
    }
  }) {
    items {
      id
      name
      description
      city
    }
  }
}

Interacting with the GraphQL API from our client application - Querying for data

Now that the GraphQL API is created we can begin interacting with it!

The first thing we'll do is perform a query to fetch data from our API.

To do so, we need to define the query, execute the query, store the data in our state, then list the items in our UI.

Read more about the Amplify GraphQL Client here.

import { API, graphqlOperation } from 'aws-amplify';
import { listRestaurants } from '../graphql/queries';
import { Restaurant } from './types/restaurant';

@Component({
  template: `
    <div>
      <div *ngFor="let restaurant of restaurants">
        {{ restaurant.name }}
      </div>
    </div>`
})
export class AppComponent implements OnInit {
  restaurants: Array<Restaurant>;

  async ngOnInit() {
    var response = await API.graphql(graphqlOperation(listRestaurants))
    this.restaurants = (response as any).data.listRestaurants.items;
  }
}

Performing mutations

Now, let's look at how we can create mutations.

import { FormBuilder, FormGroup, Validators } from '@angular/forms';
import { createRestaurant } from '../../graphql/mutations'

@Component(...)
export class HomeComponent implements OnInit {
  public createForm: FormGroup;

  constructor(private fb: FormBuilder) { }

  async ngOnInit() {
    this.createForm = this.fb.group({
      'name': ['', Validators.required],
      'description': ['', Validators.required],
      'city': ['', Validators.required]
    });
    var response = await API.graphql(graphqlOperation(listRestaurants));
    this.restaurants = (response as any).data.listRestaurants.items;
  } 
  
  public async onCreate(restaurant: any) {
    try {
      await API.graphql(graphqlOperation(createRestaurant, {
        input: restaurant
      }));
      console.log('item created!');
      this.restaurants = [restaurant, ...this.restaurants];
      this.createForm.reset();
    } 
    catch (e) {
      console.log('error creating restaurant...', e);
    }
  }
}

GraphQL Subscriptions

Next, let's see how we can create a subscription to subscribe to changes of data in our API.

To do so, we need to define the subscription, listen for the subscription, & update the state whenever a new piece of data comes in through the subscription.

import * as Observable from 'zen-observable';
import { onCreateRestaurant } from '../../graphql/subscriptions';

@Component(...)
export class HomeComponent implements OnInit {
  ngOnInit() {
    var subscription = API.graphql(
      graphqlOperation(onCreateRestaurant)
    ) as Observable<object>;
    
    subscription.subscribe({
      next: (sourceData) => {
        const newRestaurant = (sourceData as any).value.data.onCreateRestaurant
        this.restaurants = [newRestaurant, ...this.restaurants];
      }
    });
  }
}

Hosting

To deploy & host your app on AWS, we can use the hosting category.

amplify add hosting

• Select the environment setup: DEV (S3 only with HTTP)
• hosting bucket name YOURBUCKETNAME
• index doc for the website index.html
• error doc for the website index.html

Now, everything is set up & we can publish it:

amplify publish

Working with multiple environments

You can create multiple environments for your application in which to create & test out new features without affecting the main environment which you are working on.

When you create a new environment from an existing environment, you are given a copy of the entire backend application stack from the original project. When you make changes in the new environment, you are then able to test these new changes in the new environment & merge only the changes that have been made since the new environment was created back into the original environment.

Let's take a look at how to create a new environment. In this new environment, we'll re-configure the GraphQL Schema to have another field for the pet owner.

First, we'll initialize a new environment using amplify init:

amplify init

• Do you want to use an existing environment? N
• Enter a name for the environment: apiupdate
• Do you want to use an AWS profile? Y
• amplify-workshop-user

Once the new environment is initialized, we should be able to see some information about our environment setup by running:

amplify env list

| Environments |
| ------------ |
| dev          |
| *apiupdate   |

Now we can update the GraphQL Schema in amplify/backend/api/RestaurantAPI/schema.graphql to the following (adding the owner field):

type Restaurant @model {
  ...
  owner: String
}

Now, we can create this new stack by running amplify push:

amplify push

After we test it out, we can now merge it into our original dev environment:

amplify env checkout dev

amplify status

amplify push

• Do you want to update code for your updated GraphQL API? Y
• Do you want to generate GraphQL statements? Y

Deploying via the Amplify Console

We have looked at deploying via the Amplify CLI hosting category, but what about if we wanted continous deployment? For this, we can use the Amplify Console to deploy the application.

The first thing we need to do is create a new GitHub repo for this project. Once we've created the repo, we'll copy the URL for the project to the clipboard & initialize git in our local project:

git init

git remote add origin git@github.com:username/project-name.git

git add .

git commit -m 'initial commit'

git push origin master

Next we'll visit the Amplify Console in our AWS account at https://ap-southeast-1.console.aws.amazon.com/amplify/home.

Here, we'll click Get Started to create a new deployment. Next, authorize Github as the repository service.

Next, we'll choose the new repository & branch for the project we just created & click Next.

In the next screen, we'll create a new role & use this role to allow the Amplify Console to deploy these resources & click Next.

Finally, we can click Save and Deploy to deploy our application!

Now, we can push updates to Master to update our application.

Removing Services

If at any time, or at the end of this workshop, you would like to delete a service from your project & your account, you can do this by running the amplify remove command:

amplify remove auth

amplify push

If you are unsure of what services you have enabled at any time, you can run the amplify status command:

amplify status

amplify status will give you the list of resources that are currently enabled in your app.