Docker Compose Tip #27: Extension fields as metadata for tools and platforms
Extension fields aren’t just for YAML reusability - they’re powerful metadata carriers that tools can leverage for platform-specific configurations! Extension fields as metadata Any key starting with x- is ignored by Compose but preserved in the configuration: # Top-level metadata x-project-version: "2.1.0" x-team: "platform-engineering" x-environment: "production" x-region: "us-east-1" services: api: image: myapi:latest # Service-level metadata x-tier: "frontend" x-cost-center: "engineering" x-sla: "99.9" x-owner: "api-team@company.com" Compose Bridge and Kubernetes integration Extension fields can provide hints for Kubernetes deployment: ...