serverless.yml

service: learning-caching-headers
frameworkVersion: '3'

provider:
  name: aws
  stage: prod
  runtime: nodejs12.x
  region: "us-east-1"
  logRetentionInDays: 14

plugins:
  - serverless-plugin-typescript

package:
  patterns:
    - '!*/**'
    - handler.js

resources:
  Description: "CloudFormation template for ${self:service}"
  Resources:
    CloudFrontFunction:
      Type: AWS::CloudFront::Function
      Properties:
        Name: DateHeaderSet
        AutoPublish: true
        FunctionCode: !Sub |
          function handler(event) {
            var response = event.response;
          
            response.headers['date'] = {
              // https://stackoverflow.com/a/18324177/3141881
              value: new Date().toUTCString()
            };
            delete response.headers['age'];
          
            return response;
          }
        FunctionConfig:
          Comment: !Sub Update the date header
          Runtime: cloudfront-js-1.0
    CloudFrontDistribution:
      Type: AWS::CloudFront::Distribution
      Properties:
        DistributionConfig:
          Origins:
            - Id: ApiGateway
              DomainName:
                Fn::Join:
                  - "."
                  - - Ref: HttpApi
                    - execute-api
                    - Ref: AWS::Region
                    - Ref: AWS::URLSuffix
              CustomOriginConfig:
                HTTPPort: '80'
                HTTPSPort: '443'
                OriginProtocolPolicy: https-only
                OriginSSLProtocols: [ "TLSv1", "TLSv1.1", "TLSv1.2" ]
          Enabled: 'true'
          HttpVersion: http2
          IPV6Enabled: true
          DefaultCacheBehavior:
            Compress: 'true'
            ForwardedValues:
              QueryString: 'false'
              Cookies:
                Forward: none
            AllowedMethods:
              - GET
              - HEAD
              - OPTIONS
            TargetOriginId: ApiGateway
            ViewerProtocolPolicy: redirect-to-https
            FunctionAssociations:
              - EventType: viewer-response
                FunctionARN: !GetAtt CloudFrontFunction.FunctionMetadata.FunctionARN
          PriceClass: PriceClass_100
          CustomErrorResponses:
            - ErrorCode: 403
              ResponseCode: 404
              ResponsePagePath: "/404.html"
          ViewerCertificate:
            CloudFrontDefaultCertificate: true
  Outputs:
    ApiDistribution:
      Value:
        Fn::GetAtt: [ CloudFrontDistribution, DomainName ]

functions:
  hello:
    handler: handler.handleRequest
    memorySize: 128
    events:
      - httpApi:
          path: /
          method: GET