AWS CodeDeploy is a fully managed deployment service that automates application deployments to various compute services including Amazon EC2 instances, AWS Lambda functions, Amazon ECS services, and on-premises servers. It is a critical component for SysOps Administrators implementing continuous de…AWS CodeDeploy is a fully managed deployment service that automates application deployments to various compute services including Amazon EC2 instances, AWS Lambda functions, Amazon ECS services, and on-premises servers. It is a critical component for SysOps Administrators implementing continuous deployment strategies within AWS environments.
CodeDeploy supports two primary deployment types. In-place deployments update applications on existing instances by stopping the application, installing the new version, and restarting it. Blue/green deployments create new instances with the updated application, then shift traffic from the old instances to the new ones, allowing for easy rollback if issues arise.
The service uses an AppSpec file (appspec.yml or appspec.json) that defines the deployment actions. This file specifies source and destination locations for files, lifecycle event hooks, and permissions. Lifecycle hooks allow you to run scripts at various stages of deployment such as BeforeInstall, AfterInstall, ApplicationStart, and ValidateService.
CodeDeploy organizes deployments through several key components: Applications (containers for deployment configurations), Deployment Groups (sets of instances or Lambda functions targeted for deployment), Deployment Configurations (rules for deployment success and failure), and Revisions (application content and AppSpec file stored in S3 or GitHub).
For EC2 deployments, the CodeDeploy agent must be installed on target instances. This agent communicates with the CodeDeploy service to pull application revisions and execute deployment instructions.
Integration with other AWS services makes CodeDeploy powerful for automation. It works seamlessly with CodePipeline for CI/CD workflows, CloudWatch for monitoring deployment metrics and alarms, SNS for deployment notifications, and Auto Scaling groups for deploying to dynamically scaled environments.
Rollback capabilities are essential features, allowing automatic or manual rollback to previous revisions when deployments fail health checks or encounter errors, ensuring application availability and reliability.
AWS CodeDeploy: Complete Guide for AWS SysOps Administrator Associate Exam
Why AWS CodeDeploy is Important
AWS CodeDeploy is a critical service for modern cloud operations because it automates application deployments, reducing human error and enabling consistent, repeatable releases. For SysOps Administrators, understanding CodeDeploy is essential because it directly impacts system availability, deployment reliability, and operational efficiency. Organizations rely on CodeDeploy to minimize downtime during updates and ensure rapid rollback capabilities when issues arise.
What is AWS CodeDeploy?
AWS CodeDeploy is a fully managed deployment service that automates software deployments to various compute services including Amazon EC2 instances, on-premises servers, AWS Lambda functions, and Amazon ECS services. It eliminates the need for error-prone manual operations and scales to deploy applications across thousands of instances.
Key Components: • Application: A name that uniquely identifies the application being deployed • Deployment Group: A set of instances or Lambda functions targeted for deployment • Deployment Configuration: Rules determining how deployments proceed • AppSpec File: YAML or JSON file defining deployment actions • Revision: The version of your application to deploy
How AWS CodeDeploy Works
Deployment Types:
1. In-Place Deployment (EC2/On-Premises only): • Application on each instance is stopped • Latest revision is installed • New version is started and validated • Instance is taken out of service during deployment
2. Blue/Green Deployment: • New instances are provisioned (green environment) • Application is deployed to new instances • Traffic is rerouted from old (blue) to new (green) instances • Old instances can be terminated or kept for rollback
Deployment Configurations: • OneAtATime: Deploys to one instance at a time • HalfAtATime: Deploys to half of instances at once • AllAtOnce: Deploys to all instances simultaneously • Custom: Define minimum healthy instances percentage
The AppSpec File Structure: • version: Currently always 0.0 • os: Operating system (linux or windows) • files: Source and destination of application files • hooks: Lifecycle event scripts to run during deployment
• AWS CodePipeline: Orchestrates the entire CI/CD workflow • Amazon S3: Stores application revisions • GitHub/Bitbucket: Source code repositories • Elastic Load Balancing: Traffic management during Blue/Green deployments • Auto Scaling Groups: Automatic deployment to new instances • CloudWatch: Monitoring and alarms for deployments • SNS: Notifications for deployment events
Exam Tips: Answering Questions on AWS CodeDeploy
Key Concepts to Remember:
1. CodeDeploy Agent: Must be installed and running on EC2 instances and on-premises servers. Lambda and ECS deployments do not require an agent.
2. Rollback Behavior: When a deployment fails or is stopped, CodeDeploy can automatically roll back by redeploying the last known good revision. This is a new deployment, not a restoration of files.
3. Blue/Green vs In-Place: • Choose Blue/Green when you need zero-downtime deployments and easy rollback • In-Place deployments are suitable when cost is a concern and brief downtime is acceptable • Lambda and ECS only support Blue/Green deployments
4. Deployment Group Triggers: Use Amazon SNS to send notifications about deployment events to stakeholders or trigger additional automation.
5. IAM Roles Required: • Service Role: Allows CodeDeploy to call other AWS services • Instance Profile: Allows EC2 instances to access S3 for revisions
Common Exam Scenarios:
• Scenario: Minimize downtime during deployments Answer: Use Blue/Green deployment with Elastic Load Balancing
• Scenario: Deploy to on-premises servers Answer: Install CodeDeploy agent, register instances, configure IAM credentials
• Scenario: Automatic rollback on failure Answer: Enable automatic rollback in deployment group settings
• Scenario: Gradual traffic shifting for Lambda Answer: Use Linear or Canary deployment configurations
Watch Out For:
• Questions about AppSpec file location: Must be in the root of the revision bundle • Deployment failures: Often caused by agent issues, IAM permissions, or lifecycle hook script failures • Load Balancer requirement: Blue/Green deployments with EC2 require an Elastic Load Balancer or Target Group • Hooks execution: Scripts run as root (Linux) or SYSTEM (Windows) by default
Remember These Facts: • CodeDeploy is region-specific • Supports both AWS and on-premises infrastructure (hybrid deployments) • AppSpec file is YAML for EC2/On-Premises, JSON or YAML for Lambda and ECS • Deployment logs are stored in /opt/codedeploy-agent/deployment-root on Linux instances