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Kubernetes Ingress Backend

Træfik can be configured to use Kubernetes Ingress as a backend configuration.

See also Kubernetes user guide.

Configuration

################################################################
# Kubernetes Ingress configuration backend
################################################################

# Enable Kubernetes Ingress configuration backend.
[kubernetes]

# Kubernetes server endpoint.
#
# Optional for in-cluster configuration, required otherwise.
# Default: empty
#
# endpoint = "http://localhost:8080"

# Bearer token used for the Kubernetes client configuration.
#
# Optional
# Default: empty
#
# token = "my token"

# Path to the certificate authority file.
# Used for the Kubernetes client configuration.
#
# Optional
# Default: empty
#
# certAuthFilePath = "/my/ca.crt"

# Array of namespaces to watch.
#
# Optional
# Default: all namespaces (empty array).
#
# namespaces = ["default", "production"]

# Ingress label selector to filter Ingress objects that should be processed.
#
# Optional
# Default: empty (process all Ingresses)
#
# labelselector = "A and not B"

# Disable PassHost Headers.
#
# Optional
# Default: false
#
# disablePassHostHeaders = true

# Enable PassTLSCert Headers.
#
# Optional
# Default: false
#
# enablePassTLSCert = true

# Override default configuration template.
#
# Optional
# Default: <built-in template>
#
# filename = "kubernetes.tmpl"

endpoint

The Kubernetes server endpoint as URL.

When deployed into Kubernetes, Traefik will read the environment variables KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT to construct the endpoint.

The access token will be looked up in /var/run/secrets/kubernetes.io/serviceaccount/token and the SSL CA certificate in /var/run/secrets/kubernetes.io/serviceaccount/ca.crt. Both are provided mounted automatically when deployed inside Kubernetes.

The endpoint may be specified to override the environment variable values inside a cluster.

When the environment variables are not found, Traefik will try to connect to the Kubernetes API server with an external-cluster client. In this case, the endpoint is required. Specifically, it may be set to the URL used by kubectl proxy to connect to a Kubernetes cluster using the granted autentication and authorization of the associated kubeconfig.

labelselector

By default, Traefik processes all Ingress objects in the configured namespaces. A label selector can be defined to filter on specific Ingress objects only.

See label-selectors for details.

Annotations

General annotations

The following general annotations are applicable on the Ingress object:

  • traefik.frontend.rule.type: PathPrefixStrip Override the default frontend rule type. Default: PathPrefix.
  • traefik.frontend.priority: "3" Override the default frontend rule priority.
  • traefik.frontend.redirect.entryPoint: https: Enables Redirect to another entryPoint for that frontend (e.g. HTTPS).
  • traefik.frontend.redirect.regex: ^http://localhost/(.*): Redirect to another URL for that frontend. Must be set with traefik.frontend.redirect.replacement.
  • traefik.frontend.redirect.replacement: http://mydomain/$1: Redirect to another URL for that frontend. Must be set with traefik.frontend.redirect.regex.
  • traefik.frontend.entryPoints: http,https Override the default frontend endpoints.
  • traefik.frontend.passTLSCert: true Override the default frontend PassTLSCert value. Default: false.
  • ingress.kubernetes.io/rewrite-target: /users Replaces each matched Ingress path with the specified one, and adds the old path to the X-Replaced-Path header.
  • ingress.kubernetes.io/whitelist-source-range: "1.2.3.0/24, fe80::/16" A comma-separated list of IP ranges permitted for access. all source IPs are permitted if the list is empty or a single range is ill-formatted.

Note

Please note that traefik.frontend.redirect.regex and traefik.frontend.redirect.replacement do not have to be set if traefik.frontend.redirect.entryPoint is defined for the redirection (they will not be used in this case).

The following annotations are applicable on the Service object associated with a particular Ingress object:

  • traefik.backend.loadbalancer.method=drr Override the default wrr load balancer algorithm.
  • traefik.backend.loadbalancer.stickiness=true Enable backend sticky sessions.
  • traefik.backend.loadbalancer.stickiness.cookieName=NAME Manually set the cookie name for sticky sessions.
  • traefik.backend.loadbalancer.sticky=true Enable backend sticky sessions (DEPRECATED).
  • traefik.backend.circuitbreaker: <expression> Set the circuit breaker expression for the backend.

Security annotations

The following security annotations are applicable on the Ingress object:

Annotation Description
ingress.kubernetes.io/allowed-hosts:EXPR Provides a list of allowed hosts that requests will be processed. Format: Host1,Host2
ingress.kubernetes.io/custom-request-headers:EXPR Provides the container with custom request headers that will be appended to each request forwarded to the container. Format: HEADER:value||HEADER2:value2
ingress.kubernetes.io/custom-response-headers:EXPR Appends the headers to each response returned by the container, before forwarding the response to the client. Format: HEADER:value||HEADER2:value2
ingress.kubernetes.io/proxy-headers:EXPR Provides a list of headers that the proxied hostname may be stored. Format: HEADER1,HEADER2
ingress.kubernetes.io/ssl-redirect:true Forces the frontend to redirect to SSL if a non-SSL request is sent.
ingress.kubernetes.io/ssl-temporary-redirect:true Forces the frontend to redirect to SSL if a non-SSL request is sent, but by sending a 302 instead of a 301.
ingress.kubernetes.io/ssl-host:HOST This setting configures the hostname that redirects will be based on. Default is "", which is the same host as the request.
ingress.kubernetes.io/ssl-proxy-headers:EXPR Header combinations that would signify a proper SSL Request (Such as X-Forwarded-For:https). Format: HEADER:value||HEADER2:value2
ingress.kubernetes.io/hsts-max-age:315360000 Sets the max-age of the HSTS header.
ingress.kubernetes.io/hsts-include-subdomains:true Adds the IncludeSubdomains section of the STS header.
ingress.kubernetes.io/hsts-preload:true Adds the preload flag to the HSTS header.
ingress.kubernetes.io/force-hsts:false Adds the STS header to non-SSL requests.
ingress.kubernetes.io/frame-deny:false Adds the X-Frame-Options header with the value of DENY.
ingress.kubernetes.io/custom-frame-options-value:VALUE Overrides the X-Frame-Options header with the custom value.
ingress.kubernetes.io/content-type-nosniff:true Adds the X-Content-Type-Options header with the value nosniff.
ingress.kubernetes.io/browser-xss-filter:true Adds the X-XSS-Protection header with the value 1; mode=block.
ingress.kubernetes.io/content-security-policy:VALUE Adds CSP Header with the custom value.
ingress.kubernetes.io/public-key:VALUE Adds pinned HTST public key header.
ingress.kubernetes.io/referrer-policy:VALUE Adds referrer policy header.
ingress.kubernetes.io/is-development:false This will cause the AllowedHosts, SSLRedirect, and STSSeconds/STSIncludeSubdomains options to be ignored during development.
When deploying to production, be sure to set this to false.

Authentication

Is possible to add additional authentication annotations to the Ingress object. The source of the authentication is a Secret object that contains the credentials.

  • ingress.kubernetes.io/auth-type: basic Contains the authentication type. The only permitted type is basic.
  • ingress.kubernetes.io/auth-secret: mysecret Contains the username and password with access to the paths defined in the Ingress object.

The secret must be created in the same namespace as the Ingress object.

The following limitations hold:

  • The realm is not configurable; the only supported (and default) value is traefik.
  • The Secret must contain a single file only.