TraefikLearn

Rules Cheat Sheet

Quick reference for Traefik router rules and matchers.

Host Matchers

yaml
# Exact host
rule: "Host(`example.com`)"

# Multiple hosts
rule: "Host(`example.com`) || Host(`www.example.com`)"

# Wildcard subdomain
rule: "Host(`*.example.com`)"

# Regex host (HostRegexp)
rule: "HostRegexp(`{sub:[a-z]+}.example.com`)"

# Trailing dot (FQDN)
rule: "Host(`example.com.`)"

Path Matchers

yaml
# Exact path
rule: "Path(`/api/users`)"

# Path prefix
rule: "PathPrefix(`/api`)"

# Multiple paths
rule: "PathPrefix(`/api`) || PathPrefix(`/docs`)"

# Combined with host
rule: "Host(`api.example.com`) && PathPrefix(`/v2`)"

Header Matchers

yaml
# Exact header
rule: "Header(`X-Api-Key`, `secret`)"

# Regex header
rule: "HeaderRegexp(`X-Version`, `v\\d+`)"

# Multiple headers
rule: "Headers(`Content-Type`, `application/json`, `X-Auth`, `true`)"

Method Matchers

yaml
rule: "Method(`GET`)"
rule: "Method(`GET`, `POST`, `PUT`)"
rule: "Method(`POST`) || Method(`PUT`)"

Query Parameter Matchers

yaml
rule: "Query(`page`, `1`)"
rule: "Query(`format`, `json`)"
rule: "Query(`version`, `2`)"

Client IP (v3.0+)

yaml
rule: "ClientIP(`10.0.0.0/8`)"
rule: "ClientIP(`10.0.0.0/8`, `192.168.0.0/16`)"
rule: "ClientIP(`203.0.113.0/24`)"

Negation

yaml
# Exclude paths
rule: "Host(`example.com`) && !PathPrefix(`/api`)"

# Exclude methods
rule: "Host(`example.com`) && !Method(`OPTIONS`)"

TCP Matchers

yaml
tcp:
  routers:
    db:
      rule: "HostSNI(`*`)"
      rule: "HostSNI(`db.example.com`)"
      rule: "HostSNI(`*.example.com`)"
      rule: "HostSNI(`db1.example.com`) || HostSNI(`db2.example.com`)"

Priority Examples

yaml
routers:
  specific:
    rule: "Host(`api.example.com`) && PathPrefix(`/v2`)"
    priority: 10
    service: api-v2

  catch-all:
    rule: "Host(`api.example.com`)"
    priority: 1
    service: api

Common Patterns

yaml
# API Gateway
rule: "Host(`api.example.com`) && PathPrefix(`/v1`)"

# Web App
rule: "Host(`example.com`) || Host(`www.example.com`)"

# Subdomain routing
rule: "Host(`blog.example.com`)"
rule: "Host(`app.example.com`)"
rule: "Host(`admin.example.com`)"

# Path-based routing
rule: "Host(`example.com`) && PathPrefix(`/blog`)"
rule: "Host(`example.com`) && PathPrefix(`/shop`)"

# Method-based
rule: "Host(`api.example.com`) && (Method(`GET`) || Method(`POST`))"

# Multi-tenant
rule: "HostRegexp(`{tenant:[a-z]+}.example.com`)"