Errors

It Has Never Been Easier to Say That Something Went Wrong

The Errors middleware returns a custom page in lieu of the default, according to configured ranges of HTTP Status codes.

Important

The error page itself is not hosted by Traefik.

Configuration Examples

Docker & Swarm

# Dynamic Custom Error Page for 5XX Status Code
labels:
  - "traefik.http.middlewares.test-errors.errors.status=500,501,503,505-599"
  - "traefik.http.middlewares.test-errors.errors.service=serviceError"
  - "traefik.http.middlewares.test-errors.errors.query=/{status}.html"

Kubernetes

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-errors
spec:
  errors:
    status:
      - "500"
      - "501"
      - "503"
      - "505-599"
    query: /{status}.html
    service:
      name: whoami
      port: 80

Consul Catalog

# Dynamic Custom Error Page for 5XX Status Code excluding 502 and 504
- "traefik.http.middlewares.test-errors.errors.status=500,501,503,505-599"
- "traefik.http.middlewares.test-errors.errors.service=serviceError"
- "traefik.http.middlewares.test-errors.errors.query=/{status}.html"

File (YAML)

# Dynamic Custom Error Page for 5XX Status Code excluding 502 and 504
http:
  middlewares:
    test-errors:
      errors:
        status:
          - "500"
          - "501"
          - "503"
          - "505-599"
        service: serviceError
        query: "/{status}.html"

  services:
    # ... definition of error-handler-service and my-service

File (TOML)

# Dynamic Custom Error Page for 5XX Status Code excluding 502 and 504
[http.middlewares]
  [http.middlewares.test-errors.errors]
    status = ["500","501","503","505-599"]
    service = "serviceError"
    query = "/{status}.html"

[http.services]
  # ... definition of error-handler-service and my-service

In this example, the error page URL is based on the status code (query=/{status}.html).

Configuration Options

status

The status option defines which status or range of statuses should result in an error page.

The status code ranges are inclusive (505-599 will trigger with every code between 505 and 599, 505 and 599 included).

You can define either a status code as a number (500), as multiple comma-separated numbers (500,502), as ranges by separating two codes with a dash (505-599), or a combination of the two (404,418,505-599). The comma-separated syntax is only available for label-based providers. The examples above demonstrate which syntax is appropriate for each provider.

statusRewrites

An optional mapping of status codes to be rewritten. For example, if a service returns a 418, you might want to rewrite it to a 404. You can map individual status codes or even ranges to a different status code. The syntax for ranges follows the same rules as the status option.

Here is an example:

statusRewrites:
  "500-503": 500
  "418": 404

service

The service that will serve the new requested error page.

In Kubernetes, you need to reference a Kubernetes Service instead of a Traefik service.

Host Header

By default, the client Host header value is forwarded to the configured error service. To forward the Host value corresponding to the configured error service URL, the passHostHeader option must be set to false.

query

The URL for the error page (hosted by service)).

There are multiple variables that can be placed in the query option to insert values in the URL.

The table below lists all the available variables and their associated values.

Variable	Value
{status}	The response status code. It may be rewritten when using the statusRewrites option.
{originalStatus}	The original response status code, if it has been modified by the statusRewrites option.
{url}	The escaped request URL.