The Power of Serverless GraphQL with AppSync

ServerlessDays Virtual, October 2020. https://virtual.serverlessdays.io/speakers/202010/slobodan/

Transcript

1. he!o! ServerlessDays Virtual
2. every story n"ds a hero
4. Our hero
5. Works in a sma! team on a mid-sized application
6. Most of the time enjoys the job
7. Just sent a test push notification to thousands of customers
8. We need to build this new complex app.
9. Ok, no problem
10. But we have a short deadline.
11. Ok, how short?
12. It needs to be ready for yesterday. And it needs to be scalable and real-time!
13. …
14. How should I build this?
15. Don't worry, we have a famous consultant that will help you architecture the app.
16. Great!
17. multi-cloud guru
18. Just use Kubernetes! multi-cloud guru
19. But I don't know Kubernetes.
20. I don't have time to learn Kubernetes now.
21. What should I do?
22. Am I the only one who don't know Kubernetes?
23. Maybe I am not good enough for this!
25. Serverless GraphQL You should try
26. Serverless GraphQL?
27. Serverless GraphQL with AppSync The Power of
28. @slobodan_ Before we continue…
29. Slobodan Stojanović CTO @ Cloud Horizon & CTO @ Vacation Tracker co-author of Serverless Applications with Node.js book AWS Serverless Hero @slobodan_
30. Serverless GraphQL with AppSync The Power of
31. Serverless GraphQL ?
32. What's GraphQL?
33. @slobodan_ "Our biggest mistake was betting too much on HTML5" Mark Zuckerberg, 2012
34. @slobodan_
35. @slobodan_ HTML HTML
36. @slobodan_ "Our biggest mistake was betting too much on HTML5" Mark Zuckerberg, 2012
37. @slobodan_ REST? FQL? REST? FQL?
38. @slobodan_ "We were frustrated with the differences between the data we wanted to use in our apps and the server queries they required." L" Byron, 2015 GraphQL: A data query language article
39. @slobodan_ Data app needs Data app needs
40. @slobodan_
41. Nice. But, why should I care about GraphQL?
42. I don't have the same problems as Facebook.
43. Ok, but let's s" if you have one of the fo!owing problems
44. Distinct frontend clients for multiple platforms (i.e., web and mobile) has different data requirements.
45. A backend serves data to clients from different sources.
46. A complex state and caching managements for both frontend and backend.
47. Slow pages especia!y on mobile, caused by multiple dependant HTTP requests.
48. These are just some "symptoms" that GraphQL can cure.
49. • Defines a data shape • Hierarchical • Strongly typed • Protocol, not storage • Introspective • Version fr"
52. Types type Author { id: Int name: String posts: [Post] } type Post { id: Int title: String text: String author: Author }
53. Schema type Query { getAuthor(id: Int): Author getPostsByTitle(titleContains: String): [Post] } schema { query: Query }
54. Resolvers getAuthor(_, args){ return sql.raw('SELECT * FROM authors WHERE id = %s', args.id); } posts(author){ return request(`https://api.blog.io/by_author/${author.id}`); }
55. Queries { getAuthor(id: 5){ name posts { title author { # this will be the same as the name above name } } } }
56. 1. Parse 2. Validate 3. Execute
57. Result { "name": "Slobodan", "posts": [{ "title": "Hello World", "author": { "name": "Slobodan" } }, { "title": "GraphQL", "author": { "name": "Slobodan" } }] }
58. GraphQL supports: • Queries • Mutations • Subscriptions
59. Interesting!
60. Serverless GraphQL
61. Serverless GraphQL Why?
62. GraphQL using Kubernetes We!, you can deploy
63. BUT there's an easier way
65. You sti! n"d to scale these
66. Unless you make it serverless
67. How can I make my GraphQL app serverless?
68. You can make it manua!y
69. Or you can use AWS AppSync!
70. What's AWS AppSync?
71. AppSync is a managed service that uses GraphQL to make it easy for applications to get exactly the data they n"d.
72. AppSync to develop your app faster You can use
73. I can? How?
74. • Define GraphQL schema • Automatically provision a DynamoDB data source and connect resolvers • Write GraphQL queries and mutations • Use the API in the frontend app
75. It's easy to start with Let's give it a try
76. You can start with the guided schema wizard on AWS Web Console
77. But you should use AWS Amplify, CloudFormation or CDK for more serious apps
79. > amplify init > amplify add api > amplify push
80. Wow, that was fast!
81. I should show it to the consultant.
82. That will never work! Amplify is not good enough. multi-cloud guru
83. You can always start with Amplify and then move to CloudFormation or CDK
84. AppSync with CDK import * as cdk from '@aws-cdk/core'; import * as appsync from '@aws-cdk/aws-appsync'; export class AppsyncCdkAppStack extends cdk.Stack { constructor(scope: cdk.Construct, id: string, props?: cdk.StackProps) { super(scope, id, props); // Creates the AppSync API const api = new appsync.GraphqlApi(this, 'Api', { name: 'my-awesome-app', schema: appsync.Schema.fromAsset('graphql/schema.graphql'), }); // Prints out the AppSync GraphQL endpoint to the terminal new cdk.CfnOutput(this, "GraphQLAPIURL", { value: api.graphqlUrl }); } }
85. Ok, but the app needs to be real-time multi-cloud guru
86. AWS AppSync lets you specify which part of your data should be available in a real-time manner using GraphQL Subscriptions.
87. Real-time subscriptions type Subscription { addedPost: Post @aws_subscribe(mutations: ["addPost"]) updatedPost: Post @aws_subscribe(mutations: ["updatePost"]) deletedPost: Post @aws_subscribe(mutations: ["deletePost"]) }
88. And it needs to be scalable! multi-cloud guru
90. But what if you need a search functionality? multi-cloud guru
91. AWS AppSync supports Amazon Elasticsearch! the GraphQL operations can be simple lookups, complex queries & mappings, fu! text searches, fuzzy/keyword searches or geo lookups.
92. But what if you need to connect to an existing app? multi-cloud guru
93. You can connect AWS AppSync to AWS Lambda!
94. What about roles and permissions? multi-cloud guru
95. • API_KEY Authorization • AWS_IAM Authorization • OPENID_CONNECT Authorization • AMAZON_COGNITO_USER_POOLS Authorization
96. Multi-tenant? multi-cloud guru
97. You can use Cognito Groups.
98. use Resolver Mapping Template For fine-grained permissions
99. ? multi-cloud guru
100. ?
101. You can use Apache Velocity Template Language (VTL)
102. What's VTL?
103. I would say it’s an alien language (we!, its Java-based) hard to test in isolation in a serverless application, especia!y in AWS CloudForamation.
104. Alien language a.k.a. VTL #if($context.result["Owner"] == $context.identity.username) $utils.toJson($context.result) #else $utils.unauthorized() #end
105. How do you test that? multi-cloud guru
106. Testing Alien language Templates import { AppSyncMockFile } from 'amplify-appsync-simulator' import { VelocityTemplate } from 'amplify-appsync-simulator/lib/velocity' import { readFileSync } from 'fs' import { join } from 'path' import { getAppSyncSimulator } from './helpers/get-appsync-simulator' import { getVelocityRendererParams } from './helpers/get-velocity-renderer-params' // Read the VTL file from the disc const vtl = readFileSync(join(__dirname, '..', 'get-company-resolver-request.vtl'), 'utf8') const template: AppSyncMockFile = { content: vtl } // Create a simulator instance const simulator = getAppSyncSimulator() // Create a VelocityTemplate instance const velocity = new VelocityTemplate(template, simulator)
107. Testing Alien language Templates describe('some-file.vtl', () => { const { ctxValues, requestContext, info } = getVelocityRendererParams('username', { 'custom:companyId': 'company', }) test('should render a template', () => { const result = velocity.render(ctxValues, requestContext, info) expect(result).toEqual({ errors: [], isReturn: false, stash: {}, result: { version: '2018-05-29', operation: 'GetItem', key: { id: { S: 'company' }, }, }, }) }) })
108. Ha! I don't like that! multi-cloud guru
109. Me neither!
110. AppSync supports Direct Lambda Resolvers, which skips VTL completely
111. But what if you want to reuse some logic? multi-cloud guru
112. You can do that in AWS Lambda or use Pipeline Resolvers
113. Ok, ok, but this is still complex for the frontend multi-cloud guru
114. AWS Amplify gives us nice libraries for the frontend
115. And it can automatica!y generate queries, mutations, subscriptions and types for us!
116. I give up! multi-cloud guru
117. But this is not a!!
118. AppSync supports caching and offline data synchronization
119. Ok, but how do you test it? multi-cloud guru
120. It depends on your approach. It's good to have end-to-end tests, but you can test your Lambda code or VTL templates in isolation.
121. You can also run the app loca!y using AWS Amplify
122. What if we need to use more complex architecture, i.e. CQRS multi-cloud guru
123. Mutation Event storage Subscription Query Read-only table EventBridge Business logic Business logic
124. Mutation Event storage Subscription Query Read-only table EventBridge Business logic Business logic
125. Mutation Event storage Subscription Query Read-only table EventBridge Business logic Business logic
126. multi-cloud guru
128. Serverless GraphQL Guru
130. Quick Summary: • GraphQL makes your frontend and backend connection effortless • AppSync makes GraphQL management effortless • Serverless GraphQL makes you a super hero
131. @slobodan_ vacationtracker.io