URIs ending with a slash (e.g. "/something/") are "internally" redirected to "/something/index.html", i.e. the browser sees "/something/" but on the server-side the content is taken from "/something/index.html".

URIs without an extension (and not ending with a slash) will redirect with an HTTP status 301 (Moved Permanently) to the same URL with a slash appended.

Examples

/ -> internal redirect -> /index.html /foo/bar/ -> internal redirect -> /foo/bar/index.html /foo -> external redirect (301) -> /foo/ /foo.html -> no redirect /foo/bar.html -> no redirect /foo/index.html -> external redirect (301) -> /foo/

Notes

This URL scheme is somewhat opinionated. It tries to balance SEO requirements with server-side tooling. (E.g. S3 tooling tries to infer the content-type from the file extension.)

It allows you to have very nice outward facing URLs like "/cooltopic", that internally use a file with a correct extension: "cooltopic/index.html". To have content other than index.html in a folder, you need to expose the file extension: "/cooltopic/somecontent.html"

Installation

Installation via the Serverless Application Repository

Install the application "standard-redirects-for-cloudfront".
Go to the Cloudformation Console
Select the created role and edit the trust relationship, set the policy to:

{ "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Principal": { "Service": [ "lambda.amazonaws.com", "edgelambda.amazonaws.com" ] }, "Action": "sts:AssumeRole" } ] }

Select the Output Value, this is the ARN (including the version) for the Lambda function.
In CloudFront edit a Behaviour and add a Lambda Function Association of type "Event Type" and enter the Lambda function ARN from the previous step.

Manual installation

Create a function called "LATE-standard-redirects-for-cloudfront" in N. Virginia (us-east-1)
Run "npm run deploy"

This function assumes that your CloudFront distribution handles the URL "/" directly by having the property "Default Root Object" set to "index.html".

TODO: IAM, SAM