Using aws apigatewayv2 with cloudfront

Question

Pulumi · Accepted Answer

In order to demonstrate how you can use AWS API Gateway v2 with CloudFront using Pulumi, I will guide you through the steps of creating an HTTP API Gateway and configuring a distribution with CloudFront, which can cache the responses to improve latency and reduce the load on your API.

Below is a Pulumi program written in TypeScript. This script accomplishes the following:

1. Creates an HTTP API with AWS API Gateway v2, which provides you with a fully managed service for creating, publishing, maintaining, monitoring, and securing APIs at any scale.
2. Sets up a CloudFront distribution to serve as the Content Delivery Network (CDN) for the API, which caches API responses and serves them from edge locations close to the users, thus reducing latency.

I'll provide explanations for the key steps inside the code using comments. Here's the program that sets up the infrastructure:

```typescript
import * as aws from "@pulumi/aws";

// Create an HTTP API using AWS API Gateway v2.
const httpApi = new aws.apigatewayv2.Api("exampleHttpApi", {
    protocolType: "HTTP",
});

// The integration will define how API Gateway should send requests to our backend.
// In this case, it's just a mock integration as an example.
const apiIntegration = new aws.apigatewayv2.Integration("exampleApiIntegration", {
    apiId: httpApi.id,
    integrationType: "MOCK",
    integrationMethod: "GET",
});

// Create a route for the API. You can specify different routes for different actions.
const apiRoute = new aws.apigatewayv2.Route("exampleApiRoute", {
    apiId: httpApi.id,
    routeKey: "GET /", // A simple root route.
    target: pulumi.interpolate`integrations/${apiIntegration.id}`,
});

// Create a stage. This example automatically deploys to the "$default" stage.
const apiStage = new aws.apigatewayv2.Stage("exampleApiStage", {
    apiId: httpApi.id,
    autoDeploy: true,
    name: "$default",
});

// Create a CloudFront distribution that uses the HTTP API as its origin.
const apiDistribution = new aws.cloudfront.Distribution("exampleApiDistribution", {
    enabled: true,
    origins: [{
        originId: httpApi.id.apply(id => `api-${id}`),
        domainName: httpApi.apiEndpoint.apply(endpoint => endpoint.replace("https://", "")),
        customOriginConfig: {
            originProtocolPolicy: "https-only",
            httpPort: 80,
            httpsPort: 443,
        },
    }],
    defaultCacheBehavior: {
        targetOriginId: httpApi.id.apply(id => `api-${id}`),
        viewerProtocolPolicy: "redirect-to-https",
        allowedMethods: ["GET", "HEAD", "OPTIONS"],
        cachedMethods: ["GET", "HEAD", "OPTIONS"],
        // Configure the cache behavior here based on the requirements.
    },
    // Add more configurations as necessary, like logging, custom error pages, etc.
});

// Export the URL of the CloudFront distribution.
export const distributionUrl = apiDistribution.domainName;

// Export the URL of the HTTP API.
export const httpApiUrl = httpApi.apiEndpoint;
```

Here's a breakdown of what happens in this script:

- We import the necessary AWS package from Pulumi.
- We then create an AWS API Gateway v2 HTTP API (`aws.apigatewayv2.Api`).
  - This object represents your API and its base configuration. API Gateway allows the creation of REST and WebSocket APIs in addition to HTTP APIs.
- Next, we create a mock integration (`aws.apigatewayv2.Integration`) with the API Gateway.
  - This would typically be your backend application endpoint, which processes the API requests, but for simplicity, we're using a mock integration.
- A route (`aws.apigatewayv2.Route`) is created for the API, which defines how requests are to be forwarded to the backend, referencing the integration we defined.
  - A route is the part of the API that intercepts requests and defines how they are handled.
- We create a stage (`aws.apigatewayv2.Stage`) for deploying our API Gateway.
  - Stages are used in API Gateway to manage the deployment of API endpoints. In this example, we use the `$default` stage, which is auto-deployed.
- We create a CloudFront distribution (`aws.cloudfront.Distribution`) with the HTTP API as an origin.
  - Your HTTP API endpoint is set as an origin, and CloudFront will cache content from this origin. Custom origin settings specify that the API Gateway must be accessed via HTTPS only.
- Finally, we export the URL of the CloudFront distribution and our HTTP API endpoint.

This Pulumi infrastructure as code script can be run directly to create the API and CDN resources in AWS. Once the deployment is done, the URLs of the CloudFront distribution and HTTP API are provided so you can access your newly setup system.

Remember that Pulumi maintains state about your deployments, allowing you to safely make updates and track resource changes over time. With this setup, you can extend the behavior by adding more CloudFront configurations or modifying API Gateway settings to tailor the infrastructure to your specific requirements.