Using CloudFormation to configure CloudFront with an S3 origin

Question

I am trying to use CloudFormation for the first time to configure a CloudFront distribution that uses an S3 bucket as its origin.

However I am receiving the error One or more of your origins do not exist when the template is run. I have assumed it is down to the origin DomainName being configured incorrectly, however have not been able to find a configuration that works.

I currently have the following template:

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Resources": {
    "AssetBucket": {
      "Type": "AWS::S3::Bucket",
      "Properties": {
        "BucketName": "cdn-assets",
        "AccessControl": "PublicRead",
        "CorsConfiguration": {
          "CorsRules": [
            {
              "AllowedHeaders": [
                "*"
              ],
              "AllowedMethods": [
                "GET"
              ],
              "AllowedOrigins": [
                "*"
              ],
              "Id": "OpenCors",
              "MaxAge": "3600"
            }
          ]
        }
      }
    },
    "AssetCDN": {
      "Type": "AWS::CloudFront::Distribution",
      "Properties": {
        "DistributionConfig": {
          "Origins": [
            {
              "DomainName": {
                "Fn::GetAtt": [
                              "AssetBucket",
                              "DomainName"
                          ]
              },
              "Id": "AssetBucketOrigin",
              "S3OriginConfig": {}
            }
          ],
          "Enabled": "true",
          "DefaultCacheBehavior": {
            "Compress": true,
            "AllowedMethods": [
              "GET",
              "HEAD",
              "OPTIONS"
            ],
            "TargetOriginId": "origin-access-identity/cloudfront/AssetCDN",
            "ForwardedValues": {
              "QueryString": "false",
              "Cookies": {
                "Forward": "none"
              }
            },
            "ViewerProtocolPolicy": "allow-all"
          },
          "PriceClass": "PriceClass_All",
          "ViewerCertificate": {
            "CloudFrontDefaultCertificate": "true"
          }
        }
      },
      "DependsOn": [
        "AssetBucket"
      ]
    }
  }
}

I have not been able to find much advice on this, so hoping someone can point me in the right direction.

Answer 1

Your Cache Behavior's TargetOriginId property must match the value specified in the S3 Origin's Id property.

In your above example, TargetOriginId is origin-access-identity/cloudfront/AssetCDN while Id is AssetBucketOrigin, which is causing the error.

Answer 2

The real issue here is that Cloudfront have a dependency - S3 bucket. And so you should put this reference inside cloudfront object to let CFN know that first of all it should create S3 bucket. To do this you have to change your Origins.Id and DefaultCacheBehavior.TargetOriginId properties to Ref to your bucket config:

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Resources": {
    "AssetBucket": {
      "Type": "AWS::S3::Bucket",
      "Properties": {
        "BucketName": "cdn-assets",
        "AccessControl": "PublicRead",
        "CorsConfiguration": {
          "CorsRules": [
            {
              "AllowedHeaders": [
                "*"
              ],
              "AllowedMethods": [
                "GET"
              ],
              "AllowedOrigins": [
                "*"
              ],
              "Id": "OpenCors",
              "MaxAge": "3600"
            }
          ]
        }
      }
    },
    "AssetCDN": {
      "Type": "AWS::CloudFront::Distribution",
      "Properties": {
        "DistributionConfig": {
          "Origins": [
            {
              "DomainName": {
                "Fn::GetAtt": [
                              "AssetBucket",
                              "DomainName"
                          ]
              },
              "Id": { "Ref": "AssetBucket" }, /// HERE!!!!
              "S3OriginConfig": {}
            }
          ],
          "Enabled": "true",
          "DefaultCacheBehavior": {
            "Compress": true,
            "AllowedMethods": [
              "GET",
              "HEAD",
              "OPTIONS"
            ],
            "TargetOriginId": { "Ref": "AssetBucket" }, /// HERE!!!!
            "ForwardedValues": {
              "QueryString": "false",
              "Cookies": {
                "Forward": "none"
              }
            },
            "ViewerProtocolPolicy": "allow-all"
          },
          "PriceClass": "PriceClass_All",
          "ViewerCertificate": {
            "CloudFrontDefaultCertificate": "true"
          }
        }
      },
      "DependsOn": [
        "AssetBucket"
      ]
    }
  }
}