AWS Lambda examples
Reconstruct CloudFront URLs
exports.handler = (event, context, callback) => {
// Extract the request from the CloudFront event that is sent to Lambda@Edge
var request = event.Records[0].cf.request;
// Extract the URI from the request
var olduri = request.uri;
// Match any '/' that occurs at the end of a URI. Replace it with a default index
var newuri = olduri.replace(/\/$/, "/index.html");
// Replace the received URI with the URI that includes the index page
request.uri = newuri;
// Return to CloudFront
return callback(null, request);
};
Let's walk through the above example making reference to the general structure
of the
AWS Lambda handler function:
- The
event parameter is invoked to gain access to the event that triggered
the function. This is a CloudFront request event which is targetted with
event.Records[0].cf.request
- We classify this request as the
olduri since it doesn't have the form we
want.
- We mutate the original request by replacing
/ with /index.html
- We then re-assign the
request.uri value to the value of the new URI.
- Finally we invoke the
callback parameter to signal the completion of the
transformation and return the new request as the return value.
