The application directory structure in AWS deployment refers to how you organize your application files and configurations for successful deployment to AWS services like Elastic Beanstalk, Lambda, or CodeDeploy. A well-organized directory structure ensures smooth deployments and maintainable codeba…The application directory structure in AWS deployment refers to how you organize your application files and configurations for successful deployment to AWS services like Elastic Beanstalk, Lambda, or CodeDeploy. A well-organized directory structure ensures smooth deployments and maintainable codebases.
For AWS Elastic Beanstalk, the root directory typically contains your application source code along with a special .ebextensions folder. This .ebextensions directory holds configuration files (with .config extension) that customize your environment, install packages, and set environment variables.
For AWS Lambda deployments, the structure includes your handler function file at the root level, along with dependencies. When using deployment packages, all required libraries must be included in the zip file at the correct hierarchy level.
AWS CodeDeploy requires an appspec.yml file at the root of your application directory. This file defines deployment lifecycle hooks and specifies which files go where on the target instances. The structure typically includes:
- appspec.yml (required at root)
- scripts/ folder containing lifecycle hook scripts
- source/ folder with application files
- config/ folder for configuration files
For containerized applications using ECS, the directory contains a Dockerfile, buildspec.yml for CodeBuild integration, task definition files, and the application source code organized by your framework requirements.
Best practices for AWS application directory structure include separating configuration from code, using environment-specific configuration files, maintaining a clear hierarchy for static assets, and including infrastructure-as-code templates (CloudFormation or SAM templates) in a dedicated folder.
The buildspec.yml file, used with AWS CodeBuild, should reside at the root and defines build phases including install, pre_build, build, and post_build commands. Artifacts and cache locations are also specified here.
Proper directory organization facilitates automated deployments through CI/CD pipelines and ensures consistency across development, staging, and production environments.
Application Directory Structure for AWS Developer Associate
What is Application Directory Structure?
Application directory structure refers to the organized arrangement of files, folders, and configuration files within an application project. In AWS development, this structure determines how your application code, dependencies, configuration files, and deployment specifications are organized for services like AWS Elastic Beanstalk, AWS Lambda, AWS CodeDeploy, and AWS SAM.
Why is it Important?
Understanding application directory structure is crucial because:
• Deployment Success: AWS services expect specific files in specific locations. Incorrect placement causes deployment failures. • Automation: CI/CD pipelines rely on predictable directory structures to locate build artifacts and configuration files. • Maintainability: A well-organized structure makes applications easier to debug, update, and scale. • Service Integration: Different AWS services have different requirements for how applications should be packaged.
How it Works - Key AWS Service Directory Structures:
AWS Elastic Beanstalk: • Place .ebextensions/ folder at the root for configuration files • Configuration files must have .config extension • Procfile at root defines how to start your application • cron.yaml for worker environment periodic tasks
AWS Lambda: • Handler file must be at the root level or in a subdirectory specified in the handler path • Dependencies must be included in the deployment package • requirements.txt (Python) or package.json (Node.js) for dependencies
AWS SAM (Serverless Application Model): • template.yaml or template.yml at the root • Function code can be in subdirectories referenced in the template • samconfig.toml for deployment configuration
AWS CodeDeploy: • appspec.yml must be at the root of the revision • Scripts folder typically contains lifecycle hook scripts • The appspec file defines file mappings and deployment hooks
Exam Tips: Answering Questions on Application Directory Structure
1. Know the Required Files and Their Locations: • Elastic Beanstalk: .ebextensions/*.config at root • CodeDeploy: appspec.yml at root • SAM: template.yaml at root • Lambda layers: Place in /opt directory structure
2. Common Exam Scenarios: • If deployment fails, check if configuration files are in the correct location • If custom configurations are not applied, verify .ebextensions folder spelling and .config file extensions • If Lambda cannot find the handler, verify the handler path matches the actual file location
3. Remember File Naming Conventions: • appspec.yml (not appspec.yaml for CodeDeploy, though both may work) • .ebextensions files must end in .config • buildspec.yml for CodeBuild
4. Platform-Specific Structures: • Docker applications need Dockerfile or Dockerrun.aws.json • Node.js needs package.json for npm dependencies • Python needs requirements.txt for pip dependencies
5. Key Points to Remember: • Configuration files are processed in alphabetical order in .ebextensions • The appspec.yml controls the entire CodeDeploy deployment lifecycle • Lambda deployment packages have size limits (50MB zipped, 250MB unzipped) • SAM templates are CloudFormation extensions with Transform declaration
6. Troubleshooting Questions: • When environment variables are not set, check .ebextensions configuration • When hooks fail in CodeDeploy, verify script permissions and locations • When dependencies are missing, ensure they are included in the deployment package