idanielbot / cdk-http-openapi

CDK Construct that lets you build AWS Api Gateway Http Api, backed by Lambdas, based on a OpenAPI spec file.

cdk-http-openapi

CDK Construct that lets you build AWS Api Gateway Http Api, backed by Lambdas, based on a OpenAPI spec file.

Features

• Deploy Api Gateway Http Api based on a OpenAPI spec file.
• Each API Route will be backed by 1 NodeJS lambda.
• Configure CORS for your API.
• Add custom domain (eg: https://my-awesome-api.my-domain.com) to your API.
• Enable custom authorizers to Http Api Lambda integrations.
• Customize your lambdas's memory, timeouts, log retention, env variables and other stuff.

Setup

Add latest package to your project with npm/yarn

npm i --save cdk-http-openapi
yarn add -D cdk-http-openapi

Start using cdk constructs in your infrastructure definition

Examples

1. Define an Http API + 1 lambda for each route

import { HttpOpenApi } from 'cdk-http-openapi'
import { Construct } from 'constructs'
import { Stack } from 'aws-cdk-lib'

export class MyServiceStack extends Stack {
  constructor(
    scope: Construct,
    id: string,
  ) {
    super(scope, id)
    // other resources for your microservice

    // define your API + lambdas
    const api = new HttpOpenApi(this, 'MyApi', {
      functionNamePrefix: 'cool-api',
      openApiSpec: './openapi.yml',
      lambdasSourcePath: './dist/src', // optional. It defaults to './.build/src'
      integrations: [
        {
          operationId: 'getEntity', // for each operation you define in your OpenAPI spec
          handler: 'api.getEntity', // you can register a lambda handler to handle your http request
        },
        {
          operationId: 'storeEntity',
          handler: 'api.storeEntity',
          timeoutSeconds: 5,        // timeout configuration for lambda
          memorySize: 512,          // memory configuration for lambda
          env: {                    // you can also inject ENV variables into your lambda
            DB_HOST: '...',
            DB_USERNAME: '...',
            DB_PASSWORD: '...'
          },
        }
      ]
    });

  }
}

2. Enable Custom Domain for your API: my-awesome-api.cool.io

const api = new HttpOpenApi(this, 'MyApi', {
    ...
})

const domainName = 'my-awesome-api.cool.io';
const certificateArn = `arn:aws:acm:${AWS_REGION}:${AWS_ACCOUNT}:certificate/${CERTIFICATE_ID}`;
const hostedZone = 'cool.io';

api.enableCustomDomain(domainName, certificateArn, hostedZone);

3. Configure wildcard CORS (allow '*')

const api = new HttpOpenApi(this, 'MyApi', {
    functionNamePrefix: 'my-service',
    openApiSpec: './openapi.yml',

    // ... other props

    corsAllowAllOrigins: true,
    
});

4. Configure CORS more specific

const api = new HttpOpenApi(this, 'MyApi', {
    functionNamePrefix: 'my-service',
    openApiSpec: './openapi.yml',

    // ... other props

    // See AWS Docs for more info: https://docs.aws.amazon.com/apigateway/latest/developerguide/http-api-cors.html
    corsConfig: {
        allowMethods: ['GET', 'POST'],
        allowHeaders: ['application/json', 'authorization'],
        allowOrigins: ['https://my-frontend.com']
    }
});

5. Enable Customer Authorizer Lambda for your endpoints

const api = new HttpOpenApi(this, 'MyApi', {
    functionNamePrefix: 'my-service',
    openApiSpec: './openapi.yml',

    // ... other props
    
    customAuthorizerLambdaArn: `arn:aws:lambda:${AWS_REGION}:${AWS_ACCOUNT}:function:${AUTHORIZER_LAMBDA_NAME}`
   
});

cdk-http-openapi's Issues

Adding support for separation of the lambda codebase

Currently, all code that is landing in the build directory is uploaded to each lambda with all dependencies and files. It would be super cool if we could optionally separate each source code file to its specific lambda function. Shared code could be added to each lambda by using a common base layer which is attached to each lambda.

the directory structure could be looking like this:

lambda/
├─ common/
│  ├─ client.ts
│  ├─ utils.ts
├─ function-a/
│  ├─ handler.ts
│  ├─ package.json
│  ├─ package-lock.json
│  ├─ node_modules/
│  ├─ calculate.ts
├─ function-b/
│  ├─ handler.ts
│  ├─ package.json
│  ├─ package-lock.json
│  ├─ node_modules/
│  ├─ external.ts

Code example doesn't work

I copied the code example from the repo, and it doesn't work for me.

First of all there's a typo, there's a comma missing at the end of the line with lambdasSourcePath.

After fixing that, I get the error:

Argument of type '{ serviceName: string; openApiSpec: string; lambdasSourcePath: string; integrations: ({ operationId: string; handler: string; } | { operationId: string; handler: string; timeoutSeconds: number; memorySize: number; env: { ...; }; })[]; }' is not assignable to parameter of type 'HttpApiProps'.
Object literal may only specify known properties, and 'serviceName' does not exist in type 'HttpApiProps'.ts(2345)

Node version: 16.18.1
cdk version: 2.50.0

How-to add Dependencies to a lambda function then using cdk-http-openapi

Hey @iDanielBot, thanks for the CDK construct. I have a suggestion for the project. There should be a way of uploading node_modules to a lambda function directly from the library without extra scripts modifying the build directory. I could work on this.

If you have any suggestions on the implementation please let me know. 🤗