AWS ECS Error when running task: No Container Instances were found in your cluster

Question

Im trying to deploy a docker container image to AWS using ECS, but the EC2 instance is not being created. I have scoured the internet

Answer 1

I realize this is an older thread, but I stumbled on it after seeing the error the OP mentioned while following this tutorial.

Changing to an ecs-optimized AMI image did not help. My VPC already had a route 0.0.0.0/0 pointing to the subnet. My instances were added to the correct cluster, and they had the proper permissions.

Thanks to @sanath_p's link to this thread, I found a solution and took these steps:

1. Copied my Autoscaling Group's configuration
2. Set IP address type under the Advanced settings to "Assign a public IP address to every instance"
3. Updated my Autoscaling Group to use this new configuration.
4. Refreshed my instances under the Instance refresh tab.

Answer 2

Just in case someone else is blocked with this problem as I was... I've tried everything here and didn't work for me.

Besides what was said here regards the EC2 Instance Role, as commented here, in my case only worked if I still configured the EC2 Instance with simple information. Using the User Data an initial script like this:

#!/bin/bash
cat <<'EOF' >> /etc/ecs/ecs.config
ECS_CLUSTER=quarkus-ec2
EOF

Informing the related ECS Cluster Name created at this ecs config file, resolved my problem. Without this config, the ECS Agent Log at the EC2 Instance was showing an error that was not possible to connect to the ECS, doing this I've got the EC2 Instance visible to the ECS Cluster.

After doing this, I could get the EC2 Instance available for my EC2 Cluster:

The AWS documentation said that this part is optional, but in my case, it didn't work without this "optional" configuration.

Answer 3

I ran into this issue when using Fargate. I fixed it when I explicitly defined launchType="FARGATE" when calling run_task.

Answer 4

The real issue is lack of permission. As long as you create and assign a IAM Role with AmazonEC2ContainerServiceforEC2Role permission, the problem goes away.