Docker Cookbook

8.12 Creating an ECS Cluster | 263

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Run "sudo yum update" to apply all updates.
[ec2-user@ip-172-31-33-78 ~]$ docker ps
CONTAINER ID IMAGE ...
4bc4d480a362 amazon/amazon-ecs-agent:latest ...
[ec2-user@ip-172-31-33-78 ~]$ docker version
Client version: 1.6.2
Client API version: 1.18
Go version (client): go1.3.3
Git commit (client): 7c8fca2/1.6.2
OS/Arch (client): linux/amd64
Server version: 1.6.2
Server API version: 1.18
Go version (server): go1.3.3
Git commit (server): 7c8fca2/1.6.2
OS/Arch (server): linux/amd64
You see that the container instance is running Docker and that the ECS agent is a
container. The Docker version that you see will most likely be different, as Docker
releases a new version approximately every two months.
Discussion
Although you can use the default cluster, you can also create your own:
$ aws ecs create-cluster --cluster-name cookbook
---------------------------------------------------------------------------
| CreateCluster |
+-------------------------------------------------------------------------+
|| cluster ||
|+---------------------------------------------+--------------+----------+|
|| clusterArn | clusterName | status ||
|+---------------------------------------------+--------------+----------+|
|| arn:aws:ecs:us-east-1:...:cluster/cookbook | cookbook | ACTIVE ||
|+---------------------------------------------+--------------+----------+|
$ aws ecs list-clusters
-----------------------------------------------------------
| ListClusters |
+---------------------------------------------------------+
|| clusterArns ||
|+-------------------------------------------------------+|
|| arn:aws:ecs:us-east-1:587264368683:cluster/cookbook ||
|| arn:aws:ecs:us-east-1:587264368683:cluster/default ||
|+-------------------------------------------------------+|
To launch instances in that freshly created cluster instead of the default one, you need
to pass some 
user data
 during the instance creation step. Via Boto, this can be
achieved with the following script:
#!/usr/bin/env python