Fix wording of default behavior for namespaces option

2022-08-01 10:10:07 +02:00

14 KiB

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title	description
Traefik Kubernetes Ingress Documentation	Understand the requirements, routing configuration, and how to set up Traefik Proxy as your Kubernetes Ingress Controller. Read the technical documentation.

Traefik & Kubernetes

The Kubernetes Ingress Controller. {: .subtitle }

The Traefik Kubernetes Ingress provider is a Kubernetes Ingress controller; that is to say, it manages access to cluster services by supporting the Ingress specification.

Requirements

Traefik supports 1.14+ Kubernetes clusters.

Routing Configuration

See the dedicated section in routing.

Enabling and Using the Provider

You can enable the provider in the static configuration:

providers:
  kubernetesIngress: {}

[providers.kubernetesIngress]

--providers.kubernetesingress=true

The provider then watches for incoming ingresses events, such as the example below, and derives the corresponding dynamic configuration from it, which in turn creates the resulting routers, services, handlers, etc.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: foo
  namespace: production

spec:
  rules:
    - host: example.net
      http:
        paths:
          - path: /bar
            pathType: Exact
            backend:
              service:
                name:  service1
                port:
                  number: 80
          - path: /foo
            pathType: Exact
            backend:
              service:
                name:  service1
                port:
                  number: 80

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: foo
  namespace: production

spec:
  rules:
    - host: example.net
      http:
        paths:
          - path: /bar
            backend:
              serviceName: service1
              servicePort: 80
          - path: /foo
            backend:
              serviceName: service1
              servicePort: 80

LetsEncrypt Support with the Ingress Provider

By design, Traefik is a stateless application, meaning that it only derives its configuration from the environment it runs in, without additional configuration. For this reason, users can run multiple instances of Traefik at the same time to achieve HA, as is a common pattern in the kubernetes ecosystem.

When using a single instance of Traefik Proxy with Let's Encrypt, you should encounter no issues. However, this could be a single point of failure. Unfortunately, it is not possible to run multiple instances of Traefik 2.0 with Let's Encrypt enabled, because there is no way to ensure that the correct instance of Traefik receives the challenge request, and subsequent responses. Previous versions of Traefik used a KV store to attempt to achieve this, but due to sub-optimal performance that feature was dropped in 2.0.

If you need Let's Encrypt with high availability in a Kubernetes environment, we recommend using Traefik Enterprise which includes distributed Let's Encrypt as a supported feature.

If you want to keep using Traefik Proxy, LetsEncrypt HA can be achieved by using a Certificate Controller such as Cert-Manager. When using Cert-Manager to manage certificates, it creates secrets in your namespaces that can be referenced as TLS secrets in your ingress objects.

Provider Configuration

`endpoint`

Optional, Default=""

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.

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

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

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

`token`

Optional, Default=""

Bearer token used for the Kubernetes client configuration.

providers:
  kubernetesIngress:
    token: "mytoken"
    # ...

[providers.kubernetesIngress]
  token = "mytoken"
  # ...

--providers.kubernetesingress.token=mytoken

`certAuthFilePath`

Optional, Default=""

Path to the certificate authority file. Used for the Kubernetes client configuration.

providers:
  kubernetesIngress:
    certAuthFilePath: "/my/ca.crt"
    # ...

[providers.kubernetesIngress]
  certAuthFilePath = "/my/ca.crt"
  # ...

--providers.kubernetesingress.certauthfilepath=/my/ca.crt

`namespaces`

Optional, Default: []

Array of namespaces to watch. If left empty, Traefik watches all namespaces.

providers:
  kubernetesIngress:
    namespaces:
      - "default"
      - "production"
    # ...

[providers.kubernetesIngress]
  namespaces = ["default", "production"]
  # ...

--providers.kubernetesingress.namespaces=default,production

`labelSelector`

Optional, Default: ""

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

See label-selectors for details.

providers:
  kubernetesIngress:
    labelSelector: "app=traefik"
    # ...

[providers.kubernetesIngress]
  labelSelector = "app=traefik"
  # ...

--providers.kubernetesingress.labelselector="app=traefik"

`ingressClass`

Optional, Default: ""

Value of kubernetes.io/ingress.class annotation that identifies Ingress objects to be processed.

If the parameter is set, only Ingresses containing an annotation with the same value are processed. Otherwise, Ingresses missing the annotation, having an empty value, or the value traefik are processed.

??? info "Kubernetes 1.18+"

If the Kubernetes cluster version is 1.18+,
the new `IngressClass` resource can be leveraged to identify Ingress objects that should be processed.
In that case, Traefik will look for an `IngressClass` in the cluster with the controller value equal to *traefik.io/ingress-controller*.

In addition to the controller value matching mechanism, the property `ingressClass` (if set) will be used to select IngressClasses by applying a strict matching on their name.

Please see [this article](https://kubernetes.io/blog/2020/04/02/improvements-to-the-ingress-api-in-kubernetes-1.18/) for more information or the example below.

```yaml tab="IngressClass"
apiVersion: networking.k8s.io/v1beta1
kind: IngressClass
metadata:
  name: traefik-lb
spec:
  controller: traefik.io/ingress-controller
```

```yaml tab="Ingress"
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: example-ingress
spec:
  ingressClassName: traefik-lb
  rules:
  - host: "*.example.com"
    http:
      paths:
      - path: /example
        backend:
          serviceName: example-service
          servicePort: 80
```

??? info "Kubernetes 1.19+"

If the Kubernetes cluster version is 1.19+,
prefer using the `networking.k8s.io/v1` [apiVersion](https://v1-19.docs.kubernetes.io/docs/setup/release/notes/#api-change) of `Ingress` and `IngressClass`.

```yaml tab="IngressClass"
apiVersion: networking.k8s.io/v1
kind: IngressClass
metadata:
  name: traefik-lb
spec:
  controller: traefik.io/ingress-controller
```

```yaml tab="Ingress"
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
spec:
  ingressClassName: traefik-lb
  rules:
  - host: "*.example.com"
    http:
      paths:
      - path: /example
        pathType: Exact
        backend:
          service:
            name: example-service
            port:
                number: 80
```

providers:
  kubernetesIngress:
    ingressClass: "traefik-internal"
    # ...

[providers.kubernetesIngress]
  ingressClass = "traefik-internal"
  # ...

--providers.kubernetesingress.ingressclass=traefik-internal

`ingressEndpoint`

`hostname`

Optional, Default: ""

Hostname used for Kubernetes Ingress endpoints.

providers:
  kubernetesIngress:
    ingressEndpoint:
      hostname: "example.net"
    # ...

[providers.kubernetesIngress.ingressEndpoint]
  hostname = "example.net"
  # ...

--providers.kubernetesingress.ingressendpoint.hostname=example.net

`ip`

Optional, Default: ""

IP used for Kubernetes Ingress endpoints.

providers:
  kubernetesIngress:
    ingressEndpoint:
      ip: "1.2.3.4"
    # ...

[providers.kubernetesIngress.ingressEndpoint]
  ip = "1.2.3.4"
  # ...

--providers.kubernetesingress.ingressendpoint.ip=1.2.3.4

`publishedService`

Optional, Default: ""

Published Kubernetes Service to copy status from. Format: namespace/servicename.

providers:
  kubernetesIngress:
    ingressEndpoint:
      publishedService: "namespace/foo-service"
    # ...

[providers.kubernetesIngress.ingressEndpoint]
  publishedService = "namespace/foo-service"
  # ...

--providers.kubernetesingress.ingressendpoint.publishedservice=namespace/foo-service

`throttleDuration`

Optional, Default: 0

The throttleDuration option defines how often the provider is allowed to handle events from Kubernetes. This prevents a Kubernetes cluster that updates many times per second from continuously changing your Traefik configuration.

If left empty, the provider does not apply any throttling and does not drop any Kubernetes events.

The value of throttleDuration should be provided in seconds or as a valid duration format, see time.ParseDuration.

providers:
  kubernetesIngress:
    throttleDuration: "10s"
    # ...

[providers.kubernetesIngress]
  throttleDuration = "10s"
  # ...

--providers.kubernetesingress.throttleDuration=10s

`allowEmptyServices`

Optional, Default: false

If the parameter is set to true, it allows the creation of an empty servers load balancer if the targeted Kubernetes service has no endpoints available. This results in 503 HTTP responses instead of 404 ones.

providers:
  kubernetesIngress:
    allowEmptyServices: true
    # ...

[providers.kubernetesIngress]
  allowEmptyServices = true
  # ...

--providers.kubernetesingress.allowEmptyServices=true

`allowExternalNameServices`

Optional, Default: false

If the parameter is set to true, Ingresses are able to reference ExternalName services.

providers:
  kubernetesIngress:
    allowExternalNameServices: true
    # ...

[providers.kubernetesIngress]
  allowExternalNameServices = true
  # ...

--providers.kubernetesingress.allowexternalnameservices=true

Further

To learn more about the various aspects of the Ingress specification that Traefik supports, many examples of Ingresses definitions are located in the test examples of the Traefik repository.

!!! question "Using Traefik for Business Applications?"

If you are using Traefik for commercial applications,
consider the [Enterprise Edition](https://traefik.io/traefik-enterprise/).
You can use it as your:

- [Kubernetes Ingress Controller](https://traefik.io/solutions/kubernetes-ingress/)
- [Load Balancer](https://traefik.io/solutions/docker-swarm-ingress/)
- [API Gateway](https://traefik.io/solutions/api-gateway/)

Traefik Enterprise enables centralized access management,
distributed Let's Encrypt,
and other advanced capabilities.
Learn more in [this 15-minute technical walkthrough](https://info.traefik.io/watch-traefikee-demo).

14 KiB Raw Blame History

Traefik & Kubernetes

Requirements

Routing Configuration

Enabling and Using the Provider

LetsEncrypt Support with the Ingress Provider

Provider Configuration

endpoint

token

certAuthFilePath

namespaces

labelSelector

ingressClass

ingressEndpoint

hostname

ip

publishedService

throttleDuration

allowEmptyServices

allowExternalNameServices

Further

14 KiB

Raw Blame History

`endpoint`

`token`

`certAuthFilePath`

`namespaces`

`labelSelector`

`ingressClass`

`ingressEndpoint`

`hostname`

`ip`

`publishedService`

`throttleDuration`

`allowEmptyServices`

`allowExternalNameServices`