Using a custom domain name in a Private REST API Gateway

On internal networks, behind a VPC, developers might want to interact with a private API gateway. One typical use case is calling the API gateway to access a certain lambda function from a network resource that needs to make non-internet HTTPS calls without involving the AWS API.

According to the

Full Solution

1. On the VPC, create a
   


2. On the VPC Endpoints, explore the Subnets section of the VPC endpoint created in step 1 and grab the IPs


3. Create a TLS target group using the IPs from step 3.


4. Create a TLS internal NLB, using the target group from step 4.


5. Create a custom domain name in API Gateway (Regional type) but point it to the private API gateway.


6. On Route53, configure a private zone attached to the same VPC with a CNAME record that points to the NLB DNS address.

Once this is done, it should work. I have done this many times in different projects but keep forgetting about it, so I figured it was a good time to document it to be useful for someone else.