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: ...

Keep your services running! Restart policies ensure containers recover from crashes automatically. Available restart policies Docker Compose offers four restart options: services: # Never restart (default) dev-tool: image: debug-tools restart: "no" # Restart only on failure (non-zero exit) api: image: api:latest restart: on-failure # Always restart unless manually stopped web: image: nginx restart: unless-stopped # Always restart, even after Docker daemon restarts database: image: postgres:15 restart: always Choosing the right policy Development services: ...

Track everything happening in your Compose stack! Events provide real-time insights into container lifecycle changes. Basic event monitoring Watch events as they happen: # Stream all events docker compose events # JSON format for parsing docker compose events --json # Specific services only docker compose events web worker # Since a specific time docker compose events --since "2026-02-06T10:00:00" Event types Common events you’ll see: container create # Container created container start # Container started container stop # Stop initiated container die # Container exited container destroy # Container removed health_status # Health check changed network connect # Network attached network disconnect # Network detached Processing events Parse with jq: ...

Keep your Compose stack flexible! Profiles let you include or exclude services based on your current needs. Basic profiles Define optional services with profiles: services: app: image: myapp:latest ports: - "3000:3000" # No profile - always starts debug: image: debug-tools profiles: - debug # Only starts with --profile debug test-db: image: postgres:15 profiles: - test environment: POSTGRES_DB: test_db Starting with profiles Choose which services to include: ...

Build once, run everywhere! Create images that work on ARM Macs, Intel servers, and Raspberry Pi with a single build command. Configure multi-arch builder Docker Desktop handles this by default. For other Docker installations, set up buildx: # Only needed if not using Docker Desktop # Create and use a new builder docker buildx create --name multiarch --use # Verify available platforms docker buildx ls Configure platforms Specify target architectures in your compose file: ...