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import os
import boto.utils
import boto3
import requests
import datetime
import time
def get_contents(filename):
with open(filename) as f:
return f.read()
def get_ecs_introspection_url(resource):
# 172.17.0.1 is the docker network bridge ip
return 'http://172.17.0.1:51678/v1/' + resource
def contains_key(d, key):
return key in d and d[key] is not None
def get_local_container_info():
# get the docker container id
# http://docs.aws.amazon.com/AmazonECS/latest/developerguide/ecs-agent-introspection.html
docker_id = os.path.basename(get_contents("/proc/1/cpuset")).strip()
if docker_id is None:
raise Exception("Unable to find docker id")
ecs_local_task = requests.get(get_ecs_introspection_url('tasks') + '?dockerid=' + docker_id).json()
task_arn = ecs_local_task['Arn']
if task_arn is None:
raise Exception("Unable to find task arn for container %s in ecs introspection api" % docker_id)
ecs_local_container = None
if contains_key(ecs_local_task, 'Containers'):
for c in ecs_local_task['Containers']:
if c['DockerId'] == docker_id:
ecs_local_container = c
if ecs_local_container is None:
raise Exception("Unable to find container %s in ecs introspection api" % docker_id)
return ecs_local_container['Name'], task_arn
def main():
metadata = boto.utils.get_instance_metadata()
region = metadata['placement']['availability-zone'][:-1] # last char is the zone, which we don't care about
ecs_metadata = requests.get(get_ecs_introspection_url('metadata')).json()
cluster = ecs_metadata['Cluster']
container_name, task_arn = get_local_container_info()
# Get the container info from ECS. This will give us the port mappings
ecs = boto3.client('ecs', region_name=region)
response = ecs.describe_tasks(
cluster=cluster,
tasks=[
task_arn,
]
)
task = None
if contains_key(response, 'tasks'):
for t in response['tasks']:
if t['taskArn'] == task_arn:
task = t
if task is None:
raise Exception("Unable to locate task %s" % task_arn)
container = None
if contains_key(task, 'containers'):
for c in task['containers']:
if c['name'] == container_name:
container = c
if container is None:
raise Exception("Unable to find ecs container %s" % container_name)
if contains_key(container, 'networkBindings'):
for b in container['networkBindings']:
print("export PORT_%s_%d=%d;" % (b['protocol'].upper(), b['containerPort'], b['hostPort']))
if __name__ == '__main__':
main()
#!/bin/sh
set -o errexit
set -o xtrace
export EC2_HOST=$(wget -O - http://169.254.169.254/latest/meta-data/local-ipv4 2> /dev/null)
result="$(python /opt/bin/ecs-get-port-mapping.py)"
eval "$result"
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