11 Oct

Add EC2 to ECS Cluster

I have had a lot of problems with ecs-agent always connecting to the “default” cluster rather than the one I want it to connect to. All the other instructions missed one vital step – removing ecs-agent from docker and reinstalling – that way it re-reads the ECS config file – without this step I could not get ecs-agent to connect to anything other than “default” cluster.

To put an EC2 ecs-agent into a specific cluster do the following:

Edit the ecs configuration file at /etc/ecs/ecs.config: sudo vi /etc/ecs/ecs.config
Add: ECS_CLUSTER=YourCluster
Close the editor “:wq”

Stop ecs-agent: sudo docker stop ecs-agent

Remove ecs-agent from docker: sudo docker rm ecs-agent

Remove the ecs-agent checkpoint file: sudo rm /var/lib/ecs/data/ecs_agent_data.json

Optional – remove the ECS log files: sudo rm /var/log/ecs/*

Reinstall ecs-agent using the command at https://github.com/aws/amazon-ecs-agent – it was (at writing):

sudo docker run --name ecs-agent \
    --detach=true \
    --restart=on-failure:10 -d \
    --volume=/var/run/docker.sock:/var/run/docker.sock \
    --volume=/var/log/ecs:/log \
    --volume=/var/lib/ecs/data:/data \
    --net=host \
    --env-file=/etc/ecs/ecs.config \
    --env=ECS_LOGFILE=/log/ecs-agent.log \
    --env=ECS_DATADIR=/data/ \
    --env=ECS_ENABLE_TASK_IAM_ROLE=true \

Start ecs-agent: sudo docker start ecs-agent

If you are using an ECS Optimized image you will need to add the container auto-start by: sudo vi /etc/init/ecs-agent.conf
Add the lines:

description "ecs-agent container"
author "Me"
start on filesystem and started docker
stop on runlevel [!2345]
/usr/bin/docker start -a ecs-agent
end script

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