Runtime configuration for deployments refers to the practice of managing application settings and parameters that can be modified without redeploying your application code. In AWS, this is a crucial concept for maintaining flexible and maintainable applications.
Key components of runtime configura…Runtime configuration for deployments refers to the practice of managing application settings and parameters that can be modified without redeploying your application code. In AWS, this is a crucial concept for maintaining flexible and maintainable applications.
Key components of runtime configuration include:
**AWS Systems Manager Parameter Store**: This service allows you to store configuration data as plain text or encrypted strings. Parameters can be organized hierarchically and accessed by your applications at runtime. This is ideal for storing database connection strings, API keys, and feature flags.
**AWS Secrets Manager**: Specifically designed for sensitive information like credentials and API tokens. It provides automatic rotation capabilities and integrates seamlessly with RDS databases and other AWS services.
**Environment Variables**: AWS Lambda, Elastic Beanstalk, and ECS all support environment variables that can be configured during deployment. These values are injected into your application's runtime environment and can be updated through the AWS Console or CLI.
**AWS AppConfig**: A feature of Systems Manager that enables controlled deployment of configuration changes. It supports validation, gradual rollouts, and automatic rollback if issues are detected.
**Best Practices**:
1. Separate configuration from code to enable changes across environments
2. Use encryption for sensitive values
3. Implement versioning for configuration changes
4. Apply the principle of least privilege when granting access to configuration data
5. Use feature flags to control application behavior dynamically
**Benefits**:
- Reduces deployment frequency for simple configuration changes
- Enables environment-specific settings
- Improves security by centralizing secrets management
- Supports A/B testing and gradual feature rollouts
Runtime configuration is essential for twelve-factor app methodology compliance and enables DevOps teams to manage applications more efficiently across development, staging, and production environments.
Runtime Configuration for Deployments - AWS Developer Associate Guide
What is Runtime Configuration?
Runtime configuration refers to the settings, parameters, and environment variables that your application reads and uses during execution, rather than being hardcoded into the application itself. This approach allows you to modify application behavior across different deployment environments (development, staging, production) using the same codebase.
Why is Runtime Configuration Important?
• Security: Sensitive data like database credentials, API keys, and secrets should never be stored in source code • Flexibility: Change application behavior across environments using identical deployment artifacts • Compliance: Separate configuration from code to meet security and audit requirements • Scalability: Easily update configurations across multiple instances simultaneously • Cost Optimization: Use different resource settings for different environments
How Runtime Configuration Works in AWS
Key AWS Services for Runtime Configuration:
1. AWS Systems Manager Parameter Store • Stores configuration data and secrets as parameter values • Supports hierarchical storage with path-based organization • Offers standard (free) and advanced tiers • Integrates with IAM for access control • Supports versioning and change history
2. AWS Secrets Manager • Purpose-built for secrets management • Automatic rotation of credentials for RDS, Redshift, and DocumentDB • Cross-account access capabilities • Higher cost but more features for secret-specific use cases
3. Environment Variables • Lambda functions: Configure via console, CLI, or CloudFormation • Elastic Beanstalk: Environment properties in configuration • ECS: Task definition environment variables • Can reference Parameter Store or Secrets Manager values
4. AWS AppConfig • Feature flags and dynamic configuration • Validation before deployment • Gradual rollout capabilities • Rollback support
Best Practices for Runtime Configuration
• Use Parameter Store for non-sensitive configuration data • Use Secrets Manager for credentials requiring rotation • Implement least-privilege IAM policies for configuration access • Use encryption at rest (KMS) for sensitive parameters • Version your configurations for audit trails • Cache configuration values to reduce API calls and latency • Use hierarchical naming conventions (e.g., /app/environment/parameter)
Integration with Deployment Services
AWS CodeDeploy: Use appspec.yml hooks to fetch configuration during deployment AWS Elastic Beanstalk: Environment properties and .ebextensions for configuration AWS Lambda: Environment variables with optional Secrets Manager integration Amazon ECS: Task definitions can reference Secrets Manager and Parameter Store
Exam Tips: Answering Questions on Runtime Configuration
• Parameter Store vs Secrets Manager: Choose Parameter Store for general configuration and Secrets Manager when automatic credential rotation is required
• Cost Considerations: Parameter Store standard tier is free; Secrets Manager charges per secret per month
• Encryption: Both services support KMS encryption; SecureString parameters in Parameter Store require KMS
• Lambda Configuration: Environment variables are encrypted at rest by default; use Secrets Manager for sensitive data that needs rotation
• Cross-Account Access: Secrets Manager supports cross-account sharing via resource policies; Parameter Store requires IAM role assumption
• Size Limits: Parameter Store standard parameters max 4KB, advanced 8KB; Secrets Manager supports up to 64KB
• When you see questions about: - Database credentials → Think Secrets Manager with rotation - Feature flags → Think AppConfig - Application settings → Think Parameter Store - Centralized configuration → Think Parameter Store with hierarchies
• Remember: Configuration should be externalized from application code and deployment artifacts should remain identical across environments