Cloudflare, AWS API Gateway & Custom Domains

I’ve been playing with AWS Lambda on and off for a while, using SAM to deploy my lambda and access it through a custom domain.

Everything had been working fine until I recently changed the naming of my API gateway and switched from a RestAPI to a HttpAPI for my lambda functions.

My functions would work when I called them through the Invoke URL, however if I tried calling the same lambda function via the API Gateway domain name or via the custom domain name, I would get no response or a “Not Found” error.

{"message":"Not Found"}

Somewhere in my changes, possibly to do with the move to HttpAPI, the issue was the configuration of Cloudflare.

I have my SSL/TLS set to “Flexible” because I have sites hosted via S3, however, my API Gateway needed this to be “Full” to work.

If you can switch your default to “Full” that may solve your problems. For me I had to create a “Rule” in Cloudflare so that all requests to the API Gateway would use “Full” encryption.

The rule I used was focus-api*.gaunt.dev/*, and the settings were SSL and Full.

Thank you to the folks on this thread for the breadcrumbs.