Load Balancing

Now it's time to use the AMI to launch some instances and load balance.

Launching Instances

step 1:

Go an launch a new instance for the qr code app

step 2:

In the AMI section, select My AMIs, Owned by me and make sure the qr app AMI is selected

step 3:

Since we'll never login or modify this instance, proceed without a key pair

step 4:

In the network settings, click Edit

step 5:

Disable public IP assignment

We will never access these instances over the public internet

step 6:

Select Custom TCP and Port range 3000

This is the port for the internal HTTP server

step 7:

Select Custom for the Source type and enter the cidr block for the VPC.

This instance will only allow access on port 3000 from within the VPC's private network. We generally want to keep most of the infrastructure as private as possible, and only expose what's necessary.

In this case, we'll expose a load balancer to the public internet, while keeping everything else private.