Changing from port 8080 to 80 to support the Load Balancer

To change the target group port for your load balancer from 80 to 8080, you'll need to modify the target group settings. However, it's important to note that simply changing the port may not be sufficient, and other configuration changes might be necessary to ensure proper functionality.

Here's a general approach to make this change:

1. Access the Amazon EC2 console and navigate to the "Target Groups" section under "Load Balancing."

2. Select the target group associated with your load balancer.

3. On the target group's details page, you'll need to edit the group details to change the port.

4. After changing the port, you may also need to update the health check settings to ensure they're using the correct port (8080).

5. If you're using an Application Load Balancer, you might need to update the listener rules to forward traffic to the correct port on the target group.

6. For Network Load Balancers, you may need to update the listener configuration to forward traffic to the new port.

7. Ensure that your backend instances or services are actually listening on port 8080.

8. Review and update any security group rules to allow traffic on the new port.

Given the complexity of load balancer configurations and the potential impact of changes, it would indeed be advisable to have an Amazon engineer or AWS support review your entire configuration. They can provide a comprehensive assessment of what needs to be modified beyond just the port change, ensuring that all components of your load balancer setup are properly aligned with the new port configuration.
Sources
Edit target group attributes for your Network Load Balancer - Elastic Load Balancing
Update the health check settings of a Network Load Balancer target group - Elastic Load Balancing
Update the health check settings of an Application Load Balancer target group - Elastic Load Balancing
Target groups for your Application Load Balancers - Elastic Load Balancing