AWS ECS ALB Error (Request timed out)

Question

I am trying to learn/use AWS ECS but keep getting

service has reached a steady state.

Followed by:

service (instance i-05873e2a55ecba2f6) (port 32768) is unhealthy in target-group due to (reason Request timed out)

I'm not really sure which info you need to help, but I was using this load balancer across EC2 instances before, but I am replacing those EC2 instances with ones launched through ECS and now I am running into this error.

My cluster is in my default VPC and I am including all 3 subnets (East zone). The security group is my load balancer security group which allows all traffic on ports 40 and 443. I have tried changing security group so that it allows anyone on any port but that doesn't work.

My host port in my task definition is 0 and my container port is 3000 which is what I exposed in Dockerfile.

The healthcheck is just on the target port at path "/"

Answer 1

This answer summarize a checklist of points to verify when debugging this kind of error:

• be the case, there is no route Path /healthcheck in the backend service
• The status code from /healthcheck is not 200
• Might be the case that target port is invalid, configure it correctly, if an application running on port 8080 or 3000 it should be 3000 or 8080
• The security group is not allowing traffic on the target group
• Application is not running in the container