I'm trying to deploy a simple container using Amazon ECS, specifically for an API service that needs to be public facing. I'm currently running one EC2 instance, which is covered by the free tier, and its public IP address is also free. However, I'm concerned about the costs associated with two additional public IPv4 addresses that are required for my Application Load Balancer (ALB). I understand that ALB needs to operate across at least two Availability Zones, which creates a network interface that requires these public IPs. Since I believe that public IP addresses for ALB aren't free under the tier, I want to confirm if my understanding is correct or if there's a way to avoid these costs. Any help would be appreciated!
4 Answers
Yes, you're correct. If you're running an internet-facing ALB, the two public IPv4 addresses tied to its Elastic Network Interfaces (ENIs) will definitely incur costs. Unfortunately, these costs can’t be avoided if you want to expose your service externally.
Just a heads up, for public certificates, you won't be able to export them from AWS Certificate Manager. That generally only applies to private certificates, so you might need to adjust your approach depending on your security needs.
Keep in mind that the ALB comes with an hourly cost as well, on top of the public IP address charges. So it can get pretty pricey if you're trying to stick to the free tier.
Quick question—why are you considering an ALB if you only have one EC2 instance? It kind of defeats the purpose of load balancing. You could potentially set up DNS routing with something like Route 53 to point directly to your EC2's public IP, using Nginx for SSL termination within your solution.
If you're really aiming for zero-cost, you might want to skip the ALB and route your traffic directly to your EC2 instance's public IP. Alternatively, consider using API Gateway, if you're okay with transitioning from EC2/ECS.