Traefik v3 Core Knowledge

Core Concepts

┌─────────────────────────────────────────────────────────────────┐
│  PROVIDERS          ENTRYPOINTS        ROUTERS         SERVICES │
│  ──────────         ───────────        ───────         ──────── │
│  Docker labels  →   :80  (web)    →   Host rule   →   LB pool  │
│  File provider  →   :443 (websecure)  PathPrefix       backend  │
│  Kubernetes     →   :8080 (dashboard) Headers          servers  │
└─────────────────────────────────────────────────────────────────┘

• Provider: Where Traefik reads configuration (Docker, file, Kubernetes, Consul…)
• Entrypoint: Network port + protocol that Traefik listens on
• Router: Matches requests by rule (Host, PathPrefix, Header) → sends to a service
• Middleware: Transforms requests/responses between router and service
• Service: The upstream backend (load balancer with one or more servers)