Required Cloudformation Script for Blue/Green deployment on ECS - amazon-web-services

Question

I am trying to write a cloud-formation template for AWS ECS with blue green deployment support. This blue-green feature was added recently by AWS in ECS and couldn't find any reference for updating it in cloud-formation template. They have given documentation on, how to do it through UI but not through cloud-formation. I guess, AWS might not updated their cloud-formation documentation as it is a new feature. Any help to find the documentation would be appreciated. Thanking you in advance.

Answer 1

Support for blue/green deployment in CloudFormation has been added. It can be found here in the documentation:
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-ecs-service-deploymentcontroller.html
In the "Type" property you can choose "CODE_DEPLOY" as the deployment type. Hope this helps!

Answer 2

Currently cloudformation does not support the DeploymentController parameter in which you can specify CODE_DEPLOY.
Keep yourself update by visiting this page for documentation updates:
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ecs-service.html
For now - use custom cloudformation resource. Use Boto3 library to create the service with CODE_DEPLOY setting. Read more here:
https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ecs.html#ECS.Client.create_service
This is the python class which can create/delete/upadte ecs:
import boto3
from botocore.exceptions import ClientError
from typing import Any, Dict
client = boto3.client('ecs')
class Service:
#staticmethod
def create(**kwargs) -> Dict[str, Any]:
kwargs = dict(
cluster=kwargs.get('cluster'),
serviceName=kwargs.get('serviceName'),
taskDefinition=kwargs.get('taskDefinition'),
loadBalancers=kwargs.get('loadBalancers'),
serviceRegistries=kwargs.get('serviceRegistries'),
desiredCount=kwargs.get('desiredCount'),
clientToken=kwargs.get('clientToken'),
launchType=kwargs.get('launchType'),
platformVersion=kwargs.get('platformVersion'),
role=kwargs.get('role'),
deploymentConfiguration=kwargs.get('deploymentConfiguration'),
placementConstraints=kwargs.get('placementConstraints'),
placementStrategy=kwargs.get('placementStrategy'),
networkConfiguration=kwargs.get('networkConfiguration'),
healthCheckGracePeriodSeconds=kwargs.get('healthCheckGracePeriodSeconds'),
schedulingStrategy=kwargs.get('schedulingStrategy'),
deploymentController=kwargs.get('deploymentController'),
tags=kwargs.get('tags'),
enableECSManagedTags=kwargs.get('enableECSManagedTags'),
propagateTags=kwargs.get('propagateTags'),
)
kwargs = {key: value for key, value in kwargs.items() if key and value}
return client.create_service(**kwargs)
#staticmethod
def update(**kwargs: Dict[str, Any]) -> Dict[str, Any]:
filtered_kwargs = dict(
cluster=kwargs.get('cluster'),
service=kwargs.get('serviceName'),
desiredCount=kwargs.get('desiredCount'),
taskDefinition=kwargs.get('taskDefinition'),
deploymentConfiguration=kwargs.get('deploymentConfiguration'),
networkConfiguration=kwargs.get('networkConfiguration'),
platformVersion=kwargs.get('platformVersion'),
forceNewDeployment=kwargs.get('forceNewDeployment'),
healthCheckGracePeriodSeconds=kwargs.get('healthCheckGracePeriodSeconds')
)
try:
filtered_kwargs = {key: value for key, value in filtered_kwargs.items() if key and value}
return client.update_service(**filtered_kwargs)
except ClientError as ex:
if ex.response['Error']['Code'] == 'InvalidParameterException':
if 'use aws codedeploy' in ex.response['Error']['Message'].lower():
# For services using the blue/green (CODE_DEPLOY ) deployment controller,
# only the desired count, deployment configuration, and health check grace period
# can be updated using this API. If the network configuration, platform version, or task definition
# need to be updated, a new AWS CodeDeploy deployment should be created.
filtered_kwargs = dict(
cluster=kwargs.get('cluster'),
service=kwargs.get('serviceName'),
desiredCount=kwargs.get('desiredCount'),
deploymentConfiguration=kwargs.get('deploymentConfiguration'),
healthCheckGracePeriodSeconds=kwargs.get('healthCheckGracePeriodSeconds'),
)
filtered_kwargs = {key: value for key, value in filtered_kwargs.items() if key and value}
return client.update_service(**filtered_kwargs)
elif ex.response['Error']['Code'] == 'ServiceNotActiveException':
# We can not update ecs service if it is inactive.
return {'Code': 'ServiceNotActiveException'}
elif ex.response['Error']['Code'] == 'ServiceNotFoundException':
# If for some reason service was not found - don't update and return.
return {'Code': 'ServiceNotFoundException'}
raise
#staticmethod
def delete(**kwargs: Dict[str, Any]) -> Dict[str, Any]:
kwargs = dict(
cluster=kwargs.get('cluster'),
service=kwargs.get('serviceName'),
force=True
)
kwargs = {key: value for key, value in kwargs.items() if key and value}
return client.delete_service(**kwargs)