Services for blue/green deployments
AWS provides a number of tools and services to help you automate and
streamline your deployments and infrastructure.You can access these tools using the web console, CLI tools, SDKs, and IDEs..
Amazon Route 53
Amazon Route 53 is a highly available and scalable
authoritative DNS service that routes user requests for Internet-based resources to the
appropriate destination. Amazon Route 53 runs on a global network of DNS servers providing customers
with added features, such as routing based on health checks, geography, and latency. DNS is a
classic approach to blue/green deployments, allowing administrators to direct traffic by
simply updating DNS records in the hosted zone. Also, time to live (TTL) can be adjusted for
resource records; this is important for an effective DNS pattern because a shorter TTL allows
record changes to propagate faster to clients.
Elastic Load Balancing
Another common approach to routing traffic for a blue/green deployment is through the use
of load balancing technologies. Amazon Elastic Load Balancing distributes incoming application traffic across designated Amazon Elastic Compute Cloud (Amazon EC2) instances. Elastic Load Balancing scales in response to
incoming requests, performs health checking against Amazon EC2 resources, and naturally integrates
with other services, such as Auto Scaling. This makes it a great option for customers who
want to increase application fault tolerance.
Auto Scaling
Amazon EC2 Auto Scaling helps maintain application
availability and lets you scale EC2 capacity up or down automatically according to
defined conditions. The templates used to launch EC2 instances in an Auto Scaling group are
called launch configurations. You can attach different versions of launch configurations to an auto scaling group to enable blue/green deployment. You can also configure auto scaling for use with an ELB. In this configuration, the ELB balances the traffic across the EC2 instances running in an auto scaling group. You define termination policies in auto scaling groups to determine which EC2 instances to remove during a scaling action; auto scaling also allows instances to be placed in Standby
state, instead of termination, which helps with quick rollback when required. Both auto
scaling's termination policies and Standby state allow for blue/green deployment.
AWS Elastic Beanstalk
AWS Elastic Beanstalk is a fast and simple way to
get an application up and running on AWS. It’s perfect for developers who want to deploy code
without worrying about managing the underlying infrastructure. Elastic Beanstalk supports Auto Scaling and
Elastic Load Balancing, both of which allow for blue/green deployment. Elastic Beanstalk helps you run multiple
versions of your application and provides capabilities to swap the environment URLs,
facilitating blue/green deployment.
AWS OpsWorks
AWS OpsWorks is a configuration management
service based on Chef that allows customers to deploy and manage application stacks on AWS.
Customers can specify resource and application configuration, and deploy and monitor running
resources. OpsWorks simplifies cloning entire stacks when you’re preparing blue/green
environments.
AWS CloudFormation provides customers with the
ability to describe the AWS resources they need through JSON or YAML formatted templates. This service
provides very powerful automation capabilities for provisioning blue/green environments and
facilitating updates to switch traffic, whether through Route 53 DNS, ELB, or similar tools. The service can
be used as part of a larger infrastructure as code strategy, where the infrastructure is
provisioned and managed using code and software development techniques, such as version
control and continuous integration, in a manner similar to how application code is treated.
Amazon CloudWatch
Amazon CloudWatch is a monitoring service for AWS resources and applications. CloudWatch collects and visualizes metrics, ingests and monitors log files, and defines alarms. It provides system-wide visibility into resource utilization, application performance, and operational health, which are key to early detection of application health in blue/green deployments.
AWS CodeDeploy
AWS CodeDeploy is a deployment service that automates deployments to various compute types such as EC2 instances, on-premises instances, Lambda functions, or Amazon ECS services. Blue/Green deployment is a feature of CodeDeploy. CodeDeploy can also roll back deployment in case of failure. You can also use CloudWatch alarms to monitor the state of deployment and utilize CloudWatch Events to process the deployment or instance state change events.
Amazon Elastic Container Service
There are three ways traffic can be shifted during a deployment on Amazon Elastic Container Service (Amazon ECS):
-
Canary – Traffic is shifted in two increments.
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Linear – Traffic is shifted in equal
increments.
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All-at-once – All traffic is shifted to the updated
tasks.
AWS Lambda Hooks
With AWS Lambda hooks, CodeDeploy can call the Lambda function during the various lifecycle events including deployment of ECS, Lambda function deployment, and ECC2/On-premise deployment. The hooks are helpful in creating a deployment workflow for your apps.
