Map Amazon Elastic Container Service (ECS) tasks to the hosts by tag.

map-ecs-containers

#!/usr/bin/env python
import boto
import boto.ec2

cluster_name='default'
ecs_conn=boto.connect_ec2containerservice(host='ecs.us-west-2.amazonaws.com')

task_response = ecs_conn.list_tasks(cluster=cluster_name)
tasks = task_response['ListTasksResponse']['ListTasksResult']['taskArns']

task_details_response = ecs_conn.describe_tasks(cluster=cluster_name, tasks=tasks)

task_details_list = task_details_response['DescribeTasksResponse']['DescribeTasksResult']['tasks']

iarn_task_definitions = [ (task_details['containerInstanceArn'], task_details['taskArn'], task_details['taskDefinitionArn'] ) for task_details in task_details_list ]
#now that we have iarn, get the instance names for them


instances = ecs_conn.list_container_instances(cluster=cluster_name)

arns_list = instances['ListContainerInstancesResponse']['ListContainerInstancesResult']['containerInstanceArns']
# The following code doesn't work because the AWS interface is busted
#arns_str = ' '.join(arns_list)
#container_instances = ecs_conn.describe_container_instances(arns_str, cluster=cluster_name)

container_instances_resp = [ (arn, ecs_conn.describe_container_instances(arn, cluster=cluster_name)) for arn in arns_list ]
container_instances = [ (inst['ec2InstanceId'],arn)  for (arn, container) in container_instances_resp for inst in container['DescribeContainerInstancesResponse']['DescribeContainerInstancesResult']['containerInstances'] ]

ec2_conn = boto.ec2.connect_to_region('us-west-2')
#
instances = [(container_instance,i,arn) for (container_instance, arn) in container_instances for r in ec2_conn.get_all_instances(instance_ids=container_instance)  for i in r.instances]
iarns_instances_names = [(arn,(container_instance,instance.tags['Name'])) for (container_instance,instance,arn) in instances ]
instances_dict = dict(iarns_instances_names)
# We have both iarn_task_definition and instances_names_iarns, so join on iarn for a mega-tuple

for (iarn,task,definition) in iarn_task_definitions:
	(container_instance,instance_name) = instances_dict[iarn]
	print("%(iarn)s %(task)s %(definition)s %(container_instance)s %(instance_name)s" % locals())
	print("\n")

solr.json

{
  "_comment": "this example assumes a nice fat EBS volume mounted on /srv/volumes/solr, and a tag named whatever is in your family",
  "family": "solr-server1",
  "containerDefinitions": [
    {
      "name": "solr",
      "image": "makuk66/docker-solr",
      "essential": true,
      "portMappings": [
        {
          "containerPort": 8983,
          "hostPort": 8983
        }
      ],
      "command": [
        "/bin/bash", 
        "-c", 
        "/opt/solr/bin/solr -c -h YOUR_HOSTNAME_HERE -m 6g -f -s /srv/volumes/solr -z YOUR_ZKSERVER1_HERE:2181,YOUR_ZKSERVER2_HERE:2181,YOUR_ZKSERVER3_HERE:2181,YOUR_ZKSERVER4_HERE:2181,YOUR_ZKSERVER5_HERE:2181"
      ],
      "environment": [
      ],
      "mountPoints" : [
        {
          "sourceVolume": "solr",
          "containerPath": "/srv/volumes/solr"
        }

      ],
      "memory": 12000,
      "cpu": 256
    }
  ],
    "volumes": [
        {
            "name": "solr",
            "host": {
                "sourcePath": "/srv/volumes/solr"
            }
        }      
    ]
}

startup-userdata.sh

#!/bin/bash
apt-get update
#see if we should format the volume
if [[ "`sudo file -s /dev/xvdf`" == '/dev/xvdf: data' ]]; then sudo mkfs.ext4 /dev/xvdf ;fi
#mount volume
mkdir -p /srv/volumes/solr
mount /dev/xvdf /srv/volumes/solr
#install eni utility - doesn't exist on Ubuntu
#get docker (insecurely)
apt-get install -y build-essential
curl -sSL https://get.docker.com/ubuntu/ | sudo sh
#start ecs container agent
mkdir /etc/ecs
echo ECS_CLUSTER=default >> /etc/ecs/ecs.config
docker run --name ecs-agent -d -v /var/run/docker.sock:/var/run/docker.sock -v /var/log/ecs/:/log -p 127.0.0.1:51678:51678 -v /var/lib/ecs/data:/data -e ECS_LOGFILE=/log/ecs-agent.log -e ECS_LOGLEVEL=info -e ECS_DATADIR=/data -e ECS_CLUSTER=default amazon/amazon-ecs-agent:latest
#mkdir /srv/volumes/solr/...

#run apt again to encourage a delay for the instance to finish registering
apt-get install -y python-pip

pip install awscli boto


python - <<END
import json
import urllib2
import boto.utils
import boto.ec2
response = urllib2.urlopen('http://localhost:51678/v1/metadata').read()
meta = json.loads(response)
container_instance = meta['ContainerInstanceArn']
cluster_name='default'
instance_id = boto.utils.get_instance_metadata()['instance-id']
ecs_conn=boto.connect_ec2containerservice(host='ecs.us-west-2.amazonaws.com')
ec2_conn = boto.ec2.connect_to_region('us-west-2')
reservation = ec2_conn.get_all_instances(instance_ids=instance_id)
if 'start-docker-tasks' in reservation[0].instances[0].tags:
    for task in reservation[0].instances[0].tags['start-docker-tasks'].split():
        started = ecs_conn.start_task(task_definition=task, container_instances=[container_instance], cluster=cluster_name)
        print(task + " " + container_instance + " " + cluster_name)
        print(started)
END