Amazon ECS Sample App
Congratulations!
Your application is now running on a container in Amazon ECS.
' > top; /bin/date > date ; echo '
' > bottom; cat top date bottom > /usr/local/apache2/htdocs/index.html ; sleep 1; done\""
cpu: 10
entryPoint:
- sh
- "-c"
essential: false
image: busybox
memory: 200
volumesFrom:
- sourceContainer: simple-app
volumes:
- name: my-vol
family: test-cluster-taskdef
state: present
register: task_output
'''
RETURN = '''
taskdefinition:
description: a reflection of the input parameters
type: dict inputs plus revision, status, taskDefinitionArn
'''
try:
import boto
import botocore
HAS_BOTO = True
except ImportError:
HAS_BOTO = False
try:
import boto3
HAS_BOTO3 = True
except ImportError:
HAS_BOTO3 = False
from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.ec2 import boto3_conn, ec2_argument_spec, get_aws_connection_info
class EcsTaskManager:
"""Handles ECS Tasks"""
def __init__(self, module):
self.module = module
try:
region, ec2_url, aws_connect_kwargs = get_aws_connection_info(module, boto3=True)
if not region:
module.fail_json(msg="Region must be specified as a parameter, in EC2_REGION or AWS_REGION environment variables or in boto configuration file")
self.ecs = boto3_conn(module, conn_type='client', resource='ecs', region=region, endpoint=ec2_url, **aws_connect_kwargs)
except boto.exception.NoAuthHandlerFound as e:
module.fail_json(msg="Can't authorize connection - " % str(e))
def describe_task(self, task_name):
try:
response = self.ecs.describe_task_definition(taskDefinition=task_name)
return response['taskDefinition']
except botocore.exceptions.ClientError:
return None
def register_task(self, family, container_definitions, volumes):
response = self.ecs.register_task_definition(family=family,
containerDefinitions=container_definitions, volumes=volumes)
return response['taskDefinition']
def describe_task_definitions(self, family):
data = {
"taskDefinitionArns": [],
"nextToken": None
}
def fetch():
# Boto3 is weird about params passed, so only pass nextToken if we have a value
params = {
'familyPrefix': family
}
if data['nextToken']:
params['nextToken'] = data['nextToken']
result = self.ecs.list_task_definitions(**params)
data['taskDefinitionArns'] += result['taskDefinitionArns']
data['nextToken'] = result.get('nextToken', None)
return data['nextToken'] is not None
# Fetch all the arns, possibly across multiple pages
while fetch():
pass
# Return the full descriptions of the task definitions, sorted ascending by revision
return list(sorted([self.ecs.describe_task_definition(taskDefinition=arn)['taskDefinition'] for arn in data['taskDefinitionArns']], key=lambda td: td['revision']))
def deregister_task(self, taskArn):
response = self.ecs.deregister_task_definition(taskDefinition=taskArn)
return response['taskDefinition']
def main():
argument_spec = ec2_argument_spec()
argument_spec.update(dict(
state=dict(required=True, choices=['present', 'absent']),
arn=dict(required=False, type='str'),
family=dict(required=False, type='str'),
revision=dict(required=False, type='int'),
containers=dict(required=False, type='list'),
volumes=dict(required=False, type='list')
))
module = AnsibleModule(argument_spec=argument_spec, supports_check_mode=True)
if not HAS_BOTO:
module.fail_json(msg='boto is required.')
if not HAS_BOTO3:
module.fail_json(msg='boto3 is required.')
task_to_describe = None
task_mgr = EcsTaskManager(module)
results = dict(changed=False)
if module.params['state'] == 'present':
if 'containers' not in module.params or not module.params['containers']:
module.fail_json(msg="To use task definitions, a list of containers must be specified")
if 'family' not in module.params or not module.params['family']:
module.fail_json(msg="To use task definitions, a family must be specified")
family = module.params['family']
existing_definitions_in_family = task_mgr.describe_task_definitions(module.params['family'])
if 'revision' in module.params and module.params['revision']:
# The definition specifies revision. We must gurantee that an active revision of that number will result from this.
revision = int(module.params['revision'])
# A revision has been explicitly specified. Attempt to locate a matching revision
tasks_defs_for_revision = [td for td in existing_definitions_in_family if td['revision'] == revision]
existing = tasks_defs_for_revision[0] if len(tasks_defs_for_revision) > 0 else None
if existing and existing['status'] != "ACTIVE":
# We cannot reactivate an inactive revision
module.fail_json(msg="A task in family '%s' already exists for revsion %d, but it is inactive" % (family, revision))
elif not existing:
if len(existing_definitions_in_family) == 0 and revision != 1:
module.fail_json(msg="You have specified a revision of %d but a created revision would be 1" % revision)
elif existing_definitions_in_family[-1]['revision'] + 1 != revision:
module.fail_json(msg="You have specified a revision of %d but a created revision would be %d" % (revision, existing_definitions_in_family[-1]['revision'] + 1))
else:
existing = None
def _right_has_values_of_left(left, right):
# Make sure the values are equivalent for everything left has
for k, v in left.iteritems():
if not ((not v and (k not in right or not right[k])) or (k in right and v == right[k])):
# We don't care about list ordering because ECS can change things
if isinstance(v, list) and k in right:
left_list = v
right_list = right[k] or []
if len(left_list) != len(right_list):
return False
for list_val in left_list:
if list_val not in right_list:
return False
else:
return False
# Make sure right doesn't have anything that left doesn't
for k, v in right.iteritems():
if v and k not in left:
return False
return True
def _task_definition_matches(requested_volumes, requested_containers, existing_task_definition):
if td['status'] != "ACTIVE":
return None
existing_volumes = td.get('volumes', []) or []
if len(requested_volumes) != len(existing_volumes):
# Nope.
return None
if len(requested_volumes) > 0:
for requested_vol in requested_volumes:
found = False
for actual_vol in existing_volumes:
if _right_has_values_of_left(requested_vol, actual_vol):
found = True
break
if not found:
return None
existing_containers = td.get('containerDefinitions', []) or []
if len(requested_containers) != len(existing_containers):
# Nope.
return None
for requested_container in requested_containers:
found = False
for actual_container in existing_containers:
if _right_has_values_of_left(requested_container, actual_container):
found = True
break
if not found:
return None
return existing_task_definition
# No revision explicitly specified. Attempt to find an active, matching revision that has all the properties requested
for td in existing_definitions_in_family:
requested_volumes = module.params.get('volumes', []) or []
requested_containers = module.params.get('containers', []) or []
existing = _task_definition_matches(requested_volumes, requested_containers, td)
if existing:
break
if existing:
# Awesome. Have an existing one. Nothing to do.
results['taskdefinition'] = existing
else:
if not module.check_mode:
# Doesn't exist. create it.
volumes = module.params.get('volumes', []) or []
results['taskdefinition'] = task_mgr.register_task(module.params['family'],
module.params['containers'], volumes)
results['changed'] = True
elif module.params['state'] == 'absent':
# When de-registering a task definition, we can specify the ARN OR the family and revision.
if module.params['state'] == 'absent':
if 'arn' in module.params and module.params['arn'] is not None:
task_to_describe = module.params['arn']
elif 'family' in module.params and module.params['family'] is not None and 'revision' in module.params and \
module.params['revision'] is not None:
task_to_describe = module.params['family'] + ":" + str(module.params['revision'])
else:
module.fail_json(msg="To use task definitions, an arn or family and revision must be specified")
existing = task_mgr.describe_task(task_to_describe)
if not existing:
pass
else:
# It exists, so we should delete it and mark changed. Return info about the task definition deleted
results['taskdefinition'] = existing
if 'status' in existing and existing['status'] == "INACTIVE":
results['changed'] = False
else:
if not module.check_mode:
task_mgr.deregister_task(task_to_describe)
results['changed'] = True
module.exit_json(**results)
if __name__ == '__main__':
main()