Skill: configuration-management

What I do

I manage application settings, environment variables, secrets, and environment-specific configuration. I follow the Twelve-Factor App approach, keeping configuration strictly separate from code while maintaining security, auditability, and ease of use across multiple environments.

When to use me

• Managing environment-specific behaviour (dev, staging, prod).
• Handling database credentials, API keys, and sensitive tokens securely.
• Configuring third-party integrations and feature toggles.
• Setting up CI/CD pipelines and Kubernetes ConfigMaps/Secrets.
• Ensuring configuration validation at application startup.

Core principles

1. Configuration in Environment - Store config in environment variables, never in code (12-Factor).
2. Never Commit Secrets - Secrets must never enter version control; use secure vaults or secret managers.
3. Environment Parity - Keep environments as similar as possible, differing only in configuration.
4. Validation at Startup - Validate all required settings on boot; fail fast if configuration is missing or invalid.
5. Immutable Configuration - Once loaded, configuration should not change; restart to apply updates.

Patterns & examples

Pattern: Go Startup Validation

func Load() (*Config, error) {
    cfg := &Config{
        DatabaseURL: os.Getenv("DATABASE_URL"),
        JWTSecret:   os.Getenv("JWT_SECRET"),
    }
    if cfg.DatabaseURL == "" || cfg.JWTSecret == "" {
        return nil, fmt.Errorf("missing required configuration")
    }
    return cfg, nil
}

Pattern: Kubernetes Secret Usage

env:
  - name: DATABASE_URL
    valueFrom:
      secretKeyRef:
        name: app-secrets
        key: database-url

Pattern: Environment Files (.env.example)

# .env.example - Commit to Git
PORT=8080
DATABASE_URL=postgres://localhost:5432/db
JWT_SECRET=changeme # Example only

Anti-patterns

• ❌ Hardcoded Configuration - Embedding settings in source code requiring rebuilds for changes.
• ❌ Committing Secrets - Storing passwords or keys in .env files that are committed to Git.
• ❌ Configuration Sprawl - Scattered settings across dozens of files without a central registry.
• ❌ Logging Secrets - Printing configuration to logs without sanitising sensitive values.
• ❌ Default Production Secrets - Using "development" or "changeme" secrets in production.

KB Reference

~/vaults/baphled/3. Resources/Knowledge Base/AI Development System/Skills/DevOps-Operations/Configuration Management.md

Related skills

• security - Secure handling of sensitive data.
• devops - Configuration management in CI/CD pipelines.
• docker - Passing configuration to containerised applications.
• infrastructure-as-code - Declarative management of configuration state.