Ah, yes, the “I hit a URL and it doesn’t respond error.” One symptom for 20 possible underlying causes
You need to methodically go through and eliminate possibilities:
- Is your app running on some EC2 Instance / ECS? If you SSH to the app’s server, can you test it over localhost?
- If yes, can you reach the app via its private IP from another EC2 instance in the same VPC?
- If yes, is it configured to register with the ALB?
- If yes, are the ALB health checks passing?
- If yes, what routes or domain names is the ALB configured to send to the app and are those the routes you’re testing?
- If yes, does the ALB security group allow inbound connections?
- If yes, is the domain name configured to point at that ALB?