ForwardAuth

The ForwardAuth middleware delegates authentication to an external service.
If the service answers with a 2XX code, access is granted, and the original request is performed. Otherwise, the response from the authentication server is returned.

---

Forward-Request Headers

The following request properties are provided to the forward-auth target endpoint as X-Forwarded- headers.

Property	Forward-Request Header
HTTP Method	X-Forwarded-Method
Protocol	X-Forwarded-Proto
Host	X-Forwarded-Host
Request URI	X-Forwarded-Uri
Source IP-Address	X-Forwarded-For

Configuration Options

address

Field	Description
address	The address option defines the authentication server address.

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-auth
spec:
  forwardAuth:
    address: https://example.com/auth

trustForwardHeader

Field	Description
trustForwardHeader	Set the trustForwardHeader option to true to trust all X-Forwarded-* headers.

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-auth
spec:
  forwardAuth:
    address: https://example.com/auth
    trustForwardHeader: true

authResponseHeaders

Field	Description
authResponseHeaders	The authResponseHeaders option is the list of headers to copy from the authentication server response and set on forwarded request, replacing any existing conflicting headers.

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-auth
spec:
  forwardAuth:
    address: https://example.com/auth
    authResponseHeaders:
      - X-Auth-User
      - X-Secret

authResponseHeadersRegex

Field	Description
authResponseHeadersRegex	The authResponseHeadersRegex option is the regex to match headers to copy from the authentication server response and set on forwarded request, after stripping all headers that match the regex. It allows partial matching of the regular expression against the header key. The start of string (^) and end of string ($) anchors should be used to ensure a full match against the header key.

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-auth
spec:
  forwardAuth:
    address: https://example.com/auth
    authResponseHeadersRegex: ^X-

tip

Regular expressions and replacements can be tested using online tools such as Go Playground or the Regex101.

When defining a regular expression within YAML, any escaped character needs to be escaped twice: example\.com needs to be written as example\\.com.

authRequestHeaders

Field	Description
authRequestHeaders	The authRequestHeaders option is the list of the headers to copy from the request to the authentication server. It allows filtering headers that should not be passed to the authentication server. If not set or empty, then all request headers are passed.

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-auth
spec:
  forwardAuth:
    address: https://example.com/auth
    authRequestHeaders:
      - "Accept"
      - "X-CustomHeader"

addAuthCookiesToResponse

Field	Description
addAuthCookiesToResponse	The addAuthCookiesToResponse option is the list of cookies to copy from the authentication server to the response, replacing any existing conflicting cookie from the forwarded response.

info

Please note that all backend cookies matching the configured list will not be added to the response.

apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: test-auth
spec:
  forwardAuth:
    address: https://example.com/auth
    addAuthCookiesToResponse:
      - Session-Cookie
      - State-Cookie

tls

Field	Description	Required
tls	Defines the TLS configuration used for the secure connection to the authentication server.	No

ca

Field	Description	Required
ca	ca is the path to the certificate authority used for the secured connection to the authentication server, it defaults to the system bundle.	No

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-auth
spec:
  forwardAuth:
    address: https://example.com/auth
    tls:
      caSecret: mycasercret

---
apiVersion: v1
kind: Secret
metadata:
  name: mycasercret
  namespace: default

data:
  # Must contain a certificate under either a `tls.ca` or a `ca.crt` key. 
  tls.ca: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCi0tLS0tRU5EIENFUlRJRklDQVRFLS0tLS0=

cert

Field	Description	Required
cert	cert is the path to the public certificate used for the secure connection to the authentication server. When using this option, setting the key option is required.	No

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-auth
spec:
  forwardAuth:
    address: https://example.com/auth
    tls:
      certSecret: mytlscert

---
apiVersion: v1
kind: Secret
metadata:
  name: mytlscert
  namespace: default

data:
  tls.crt: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCi0tLS0tRU5EIENFUlRJRklDQVRFLS0tLS0=
  tls.key: LS0tLS1CRUdJTiBQUklWQVRFIEtFWS0tLS0tCi0tLS0tRU5EIFBSSVZBVEUgS0VZLS0tLS0=

info

For security reasons, the field does not exist for Kubernetes IngressRoute, and one should use the secret field instead.

key

Field	Description	Required
key	key is the path to the private key used for the secure connection to the authentication server. When using this option, setting the cert option is required.	No

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-auth
spec:
  forwardAuth:
    address: https://example.com/auth
    tls:
      certSecret: mytlscert

---
apiVersion: v1
kind: Secret
metadata:
  name: mytlscert
  namespace: default

data:
  tls.crt: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCi0tLS0tRU5EIENFUlRJRklDQVRFLS0tLS0=
  tls.key: LS0tLS1CRUdJTiBQUklWQVRFIEtFWS0tLS0tCi0tLS0tRU5EIFBSSVZBVEUgS0VZLS0tLS0=

info

For security reasons, the field does not exist for Kubernetes IngressRoute, and one should use the secret field instead.

insecureSkipVerify

Field	Description	Default	Required
insecureSkipVerify	If insecureSkipVerify is true, the TLS connection to the authentication server accepts any certificate presented by the server regardless of the hostnames it covers.	false	No

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-auth
spec:
  forwardAuth:
    address: https://example.com/auth
    tls:
      insecureSkipVerify: true

Example

Forward authentication to example.com

apiVersion: traefik.io/v1alpha1
kind: Middleware
metadata:
  name: test-auth
spec:
  forwardAuth:
    address: https://example.com/auth