title: Unable to register ECS task from boto3
body: <p>I am trying to create a basic cloud infrastructure which can run through any AWS account. I am using python boto3 module to create a cluster,task definition and a service, which are created successfully from my code. However the task in not running from my service, when I checked the Events I can see error <strong>'service my_service was unable to place a task because no container instance met all of its requirements. Reason: No Container Instances were found in your cluster'</strong>. </p>
  
  <pre><code>import boto3
  client = boto3.client('ecs')
  cluster_response = client.create_cluster(
      clusterName='my_cluster',
  )
  print(cluster_response)
  
  taskdef_response = client.register_task_definition(
      family = 'my_taskdef',
      containerDefinitions=[
          {
              'name': 'my_taskdef',
              'image': '****/sample:latest'
          }
      ],
      memory='256',
      cpu='1024',
      taskRoleArn='ecsTaskExecutionRole'
  )
  print(taskdef_response)
  service_response = client.create_service(
      cluster='my_cluster',
      serviceName='my_service',
      taskDefinition='my_taskdef',
      desiredCount=1,
      launchType='EC2'
  )
  print(service_response)
  </code></pre>
  
  <p>I am expecting this to run my docker image in the task spawned by the service. The AWS account does not have any existing EC2 instance and I want to run a task that creates EC2 instance from this code(without the need of changing anything from inside EC2 instance). How can I run the task?</p>