Block all IP access to database droplet, except for one

Using ufw, first you need to deny all traffic to your database port

sudo ufw deny 3306/tcp

then allow your IP to your server:

sudo ufw allow from Your.IP.Address to any port 3306 proto tcp

https://help.ubuntu.com/community/UFW

Heya,

You should configure the firewall on your MongoDB droplet to only allow incoming connections from the IP address of your NGINX droplet. You can do this using ufw, the Uncomplicated Firewall, which is a frontend for managing iptables.

First, you need to check the IP address of your NGINX droplet:

curl ifconfig.me

Make note of the NGINX droplet’s public IP address.

Next, on your MongoDB droplet, allow incoming connections from the NGINX droplet’s IP address:

sudo ufw allow from NGINX_DROPLET_IP to any port 27017

Replace NGINX_DROPLET_IP with the actual IP address of your NGINX droplet.

Enable the firewall if it’s not already enabled:

sudo ufw enable

Now, your MongoDB droplet should only allow incoming connections from the NGINX droplet’s IP address. Other external connections will be blocked by the firewall, and MongoDB will only be accessible locally on the MongoDB droplet itself.

Please make sure to replace NGINX_DROPLET_IP with the actual IP address of your NGINX droplet and ensure that your MongoDB application still functions as expected after making these changes.

Hope that this helps!