Kubernetes CRD

Traefik provides some Kubernetes Custom Resources, such as IngressRoute, Middleware, etc.

When using KubernetesCRD as a provider, Traefik uses Custom Resource Definition to retrieve its routing configuration. Traefik Custom Resource Definitions are listed below.

When Traefik is installed using the Helm Chart, by default, the provider kubernetesCRD is enabled.

Requirements¶

When you install Traefik without using the Helm Chart, or when you are upgrading the stack using Helm, ensure that you satisfy the following requirements:

Add/update all the Traefik resources definitions
Add/update the RBAC for the Traefik custom resources

# Install Traefik Resource Definitions:
kubectl apply -f https://raw.githubusercontent.com/traefik/traefik/v3.2/docs/content/reference/dynamic-configuration/kubernetes-crd-definition-v1.yml

# Install RBAC for Traefik:
kubectl apply -f https://raw.githubusercontent.com/traefik/traefik/v3.2/docs/content/reference/dynamic-configuration/kubernetes-crd-rbac.yml

Configuration Example¶

You can enable the kubernetesCRD provider as detailed below:

File (YAML)

providers:
  kubernetesCRD: {}

File (TOML)

[providers.kubernetesCRD]

CLI

--providers.kubernetescrd=true

Helm Chart Values

## Values file
providers:
  kubernetesCRD:
    enabled: true

Configuration Options¶

Field	Description	Default	Required
`providers.providersThrottleDuration`	Minimum amount of time to wait for, after a configuration reload, before taking into account any new configuration refresh event. If multiple events occur within this time, only the most recent one is taken into account, and all others are discarded. This option cannot be set per provider, but the throttling algorithm applies to each of them independently.	2s	No
`providers.kubernetesCRD.endpoint`	Server endpoint URL. More information here.	""	No
`providers.kubernetesCRD.token`	Bearer token used for the Kubernetes client configuration.	""	No
`providers.kubernetesCRD.certAuthFilePath`	Path to the certificate authority file. Used for the Kubernetes client configuration.	""	No
`providers.kubernetesCRD.namespaces`	Array of namespaces to watch. If left empty, watch all namespaces.	{}	No
`providers.kubernetesCRD.labelselector`	Allow filtering on specific resource objects only using label selectors. Only to Traefik Custom Resources (they all must match the filter). No effect on Kubernetes `Secrets`, `EndpointSlices` and `Services`. See label-selectors for details.	""	No
`providers.kubernetesCRD.ingressClass`	Value of `kubernetes.io/ingress.class` annotation that identifies resource objects to be processed. If empty, resources missing the annotation, having an empty value, or the value `traefik` are processed.	""	No
`providers.kubernetesCRD.throttleDuration`	Minimum amount of time to wait between two Kubernetes events before producing a new configuration. This prevents a Kubernetes cluster that updates many times per second from continuously changing your Traefik configuration. If empty, every event is caught.	0s	No
`providers.kubernetesCRD.allowEmptyServices`	Allows creating a route to reach a service that has no endpoint available. It allows Traefik to handle the requests and responses targeting this service (applying middleware or observability operations) before returning a `503` HTTP Status.	false	No
`providers.kubernetesCRD.allowCrossNamespace`	Allows the `IngressRoutes` to reference resources in namespaces other than theirs.	false	No
`providers.kubernetesCRD.allowExternalNameServices`	Allows the `IngressRoutes` to reference ExternalName services.	false	No
`providers.kubernetesCRD.nativeLBByDefault`	Allow using the Kubernetes Service load balancing between the pods instead of the one provided by Traefik for every `IngressRoute` by default. It can br overridden in the `ServerTransport`.	false	No
`providers.kubernetesCRD.disableClusterScopeResources`	Prevent from discovering cluster scope resources (`IngressClass` and `Nodes`). By doing so, it alleviates the requirement of giving Traefik the rights to look up for cluster resources. Furthermore, Traefik will not handle IngressRoutes with IngressClass references, therefore such Ingresses will be ignored (please note that annotations are not affected by this option). This will also prevent from using the `NodePortLB` options on services.	false	No

endpoint¶

The Kubernetes server endpoint URL.

When deployed into Kubernetes, Traefik reads the environment variables KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT or KUBECONFIG to construct the endpoint.

The access token is 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 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 tries 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 authentication and authorization of the associated kubeconfig.

File (YAML)

providers:
  kubernetesCRD:
    endpoint: "http://localhost:8080"
    # ...

File (TOML)

[providers.kubernetesCRD]
  endpoint = "http://localhost:8080"
  # ...

CLI

--providers.kubernetesCRD.endpoint=http://localhost:8080

Routing Configuration¶

See the dedicated section in routing.

List of Resources¶

Resource	Purpose
IngressRoute	HTTP Routing
Middleware	Tweaks the HTTP requests before they are sent to your service
TraefikService	Abstraction for HTTP loadbalancing/mirroring
TLSOptions	Allows configuring some parameters of the TLS connection
TLSStores	Allows configuring the default TLS store
ServersTransport	Allows configuring the transport between Traefik and the backends
IngressRouteTCP	TCP Routing
MiddlewareTCP	Tweaks the TCP requests before they are sent to your service
ServersTransportTCP	Allows configuring the transport between Traefik and the backends
IngressRouteUDP	UDP Routing

Particularities¶

The usage of name and namespace to refer to another Kubernetes resource.
The usage of secret for sensitive data (TLS certificates and credentials).

Full Example¶

For additional information, refer to the full example with Let's Encrypt.

Using Traefik OSS in Production?

If you are using Traefik at work, consider adding enterprise-grade API gateway capabilities or commercial support for Traefik OSS.

Adding API Gateway capabilities to Traefik OSS is fast and seamless. There's no rip and replace and all configurations remain intact. See it in action via this short video.