Publicly accessing AWS RDS from outside VPC

Question

I have a VPC configured with 3 X public and private subnets and an IGW for the public, NAT Gateway for the private.

When I create an RDS instance, I flag it as publically available. When I try to access the RDS endpoint, my connection fails.

I have created a security group to allow all traffic: 0.0.0.0/0, my VPC allows traffic coming from my network.

If I place my RDS in the public subnet, then I can connect as the IGW allows the connection. But when it is placed in the private subnet, the connection fails?

I have reviewed a fair bit of material on AWS and forums - but I cannot seem to finalise the connection. Is there something I am missing in the configuration?

Any help would be greatly appreciated.

Cheers.

Answer 1

After looking into setting up an RDS instance with a connection outside the VPC to a client/application, I came across the following:

AWS suggests the following connections to an RDS:

1. An EC2 instance in the Same VPC
2. An EC2 instance in a different VPC
3. An EC2 instance not in a VPC
4. A client application through the Internet

Without using an EC2, you would have to place the RDS in a public subnet with an Internet Gateway attached and security group set up for incoming traffic.

Here is a reference link for you - A DB Instance in a VPC Accessed by a Client Application Through the Internet