What should be done to accomplish this?
Create a customer gateway to connect to Amazon S3. Modify the route table of the private subnets to use the customer gateway.
Create a gateway VPC endpoint for Amazon S3. Modify the route table of the private subnets to use the gateway VPC endpoint.
Create a NAT gateway in the private subnets. Modify the route table of the subnets to use the NAT gateway.
Create an S3 bucket policy to allow connections from the private subnets. Modify the route table.
Explanations:
A customer gateway is used for VPN connections, not for direct access to Amazon S3. S3 access from private subnets does not require a customer gateway.
A gateway VPC endpoint for S3 allows secure, private connections to S3 from the VPC without requiring internet access or a NAT gateway. This is the recommended approach for private subnet access to S3.
A NAT gateway would allow internet access from private subnets, but it is not necessary or optimal for accessing Amazon S3. A VPC endpoint is a more secure and cost-effective solution.
An S3 bucket policy alone does not provide network-level access. The route table must also be modified to route traffic correctly to S3 via a gateway endpoint or NAT gateway.
From what I’ve heard, the answer is:
Create a gateway VPC endpoint for Amazon S3. Modify the route table of the private subnets to use the gateway VPC endpoint.