AWS CI CD Services - AWS CodeDeploy

AWS CodeDeploy

• AWS CodeDeploy is a deployment service that automates code deployments to any instance, including Amazon EC2 instances and instances running on-premises or serverless lambda functions.
• AWS CodeDeploy makes it easier for you to rapidly release new features, helps you avoid downtime during deployment, and handles the complexity of updating your applications.
• Once the automated deployment is configured & tested for one instance, the complexity of updating the applications is completely off your shoulders
• With suitable deployment type, you can completely avoid downtime and also configure to rollback automatically, in case of failure.
• You can deploy a nearly unlimited variety of application content, such as code, serverless AWS Lambda functions, web and configuration files, executables, packages, scripts, multimedia files, and so on.
• AWS CodeDeploy works with various systems for configuration management, source control, continuous integration, continuous delivery, and continuous deployment
• Production Integrations page on CodePipline will tell you the pre-built integrations for popular third-party services that are certified by the partners

AWS CodeDeploy Components

Here you go with the components of AWS CodeDeploy

Application: An application is a collection of software and configuration to be deployed to a group of instances. Typically, the instances in the group run the same software. For example, if you have a large distributed system, the web tier will likely constitute one application and the data tier another application.

Revision: A revision is a specific version of deployable content, such as source code, post-build artifacts, web pages, executable files, and deployment scripts, along with an AppSpec file. The AWS CodeDeploy Agent can access a revision from GitHub or an Amazon S3 bucket.

Deployment Group: A deployment group is for grouping EC2 instances or AWS Lambda functions in a CodeDeploy deployment.

appspec.yml is configuration file which specifies the files to be copied and scripts to executed as part of deployment

Deployment configuration: A set of deployment rules that defines the deployment success and failure conditions used by AWS CodeDeploy during a deployment. 

For example, if your application needs at least 50% of the instances in a deployment group to be up and serving traffic, you can specify that in your deployment configuration so that a deployment does not cause downtime. If no deployment configuration is associated with either the deployment or the deployment group, then by default AWS CodeDeploy will deploy to one instance at a time.

There are two types of compute platform on which AWS CodeDeploy deploys an application namely EC2/On-Premises & AWS Lambda. 

In an EC2/On-Premises deployment, a deployment group is a set of individual instances targeted for a deployment.

Deployment is an action of deploying new revision into a instance.

Deployment type is nothing but the method used to make the latest application revision available onto the instances in a deployment group. There are 2 types of deployment – In-place deployment & Blue / Green Deployment.

Instance Setup: Instance setup is key here:

• Verify your instance has an IAM instance profile and verify the permissions allows it to participate in AWS CodeDeploy deployment
• Tag the instance - or make sure it is in Auto Scaling Group
• Install the agent (can be automated)
• Verify the agent is running