traefik/integration/fixtures/error_pages/simple.toml

[global]
checkNewVersion = false
sendAnonymousUsage = false

[log]
logLevel = "DEBUG"

[entrypoints]
  [entrypoints.web]
  address = ":8080"

[providers]
   [providers.file]

[http.routers]
  [http.routers.router1]
      Rule = "Host(`test.local`)"
      service = "service1"
      middlewares = ["error"]

[http.middlewares]
    [http.middlewares.error.errors]
        status = ["500-502", "503-599"]
        service = "error"
        query = "/50x.html"

[http.services]
  [http.services.service1.loadbalancer]
    passHostHeader = true
    [[http.services.service1.loadbalancer.servers]]
        url = "http://{{.Server1}}:80"
        weight = 1

  [http.services.error.loadbalancer]
    [[http.services.error.loadbalancer.servers]]
        url = "http://{{.Server2}}:80"
        weight = 1