Cannot connect RDS that was previously private to EC2 or local

I know questions like this have been asked before but even if I follow the suggested advices, I cannot get a solution.

Previously I had a private RDS instance with postgres that was working fine with a Django web application hosted in an EC2 instance in my VPC.

Now I have the need to do a pg_dump from my local machine, so I thought of changing the public accesibility so I did. Since I had no succes but the website was still working I looked for answers and turns that I needed to accept inbound traffic in the security groups and in ACL. so I did and now not even in my local nor in my EC2 I can connect to the db, so the website stopped working. Any clues? I've been on this all weekend. Thanks.

It appears that your situation is:

• The Amazon EC2 instance can connect to the Amazon RDS database (both within the same VPC)
• You cannot access the RDS database from your local machine

There are two approaches you can take:

Option 1: Make the database public

To access the RDS database from outside of the VPC:

• The database will need to be configured as Publicly Accessible = Yes
• The security group will need to permit inbound access on the RDS database from your IP address

However, this isn't great for security because there is a danger of exposing the database to the Internet.

Option 2: Use a Jump-box

You could access the RDS database without any configuration changes, but the connection needs to appear to be coming from within the VPC. You can do it as follows:

• Launch an Amazon EC2 instance that is publicly accessible (or, if your existing EC2 instance is publicly accessible, you can use it)
• SSH into the EC2 instance using port forwarding. This will send traffic from your computer to the EC2 instance, which can then forward it to the RDS instance.

First, confirm that you can SSH into the EC2 instance. You would use a command similar to:

ssh -i key.pem ec2-user@IP-ADDRESS

If the above works, then modify the SSH command to use port forwarding:

ssh -i key.pem -L 5432:RDS-HOST-NAME:5432 ec2-user@IP-ADDRESS

This will forward port 5432 on your own computer to the EC2 instance via SSH. Then, any traffic sent to localhost:5432 will be forwarded across the SSH connection. The EC2 instance will then send the traffic to RDS-HOST-NAME:5432. (Replace RDS-HOST-NAME with the DNS Name of the RDS database.)

Then, in another Terminal window, you would run:

pg_dump --host localhost --port 5432 ...