Traefik & Kubernetes

The Kubernetes Ingress Controller.

Routing Configuration

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

Configuration Example

Configuring Kubernetes Ingress Controller

RBAC

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: traefik-ingress-controller
rules:
  - apiGroups:
      - ""
    resources:
      - services
      - secrets
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - discovery.k8s.io
    resources:
      - endpointslices
    verbs:
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io
    resources:
      - ingresses
      - ingressclasses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io
    resources:
      - ingresses/status
    verbs:
      - update
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: traefik-ingress-controller
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: traefik-ingress-controller
subjects:
  - kind: ServiceAccount
    name: traefik-ingress-controller
    namespace: default

Ingress

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myingress
  annotations:
    traefik.ingress.kubernetes.io/router.entrypoints: web
spec:
  rules:
    - host: example.com
      http:
        paths:
          - path: /bar
            pathType: Exact
            backend:
              service:
                name:  whoami
                port:
                  number: 80
          - path: /foo
            pathType: Exact
            backend:
              service:
                name:  whoami
                port:
                  number: 80

Traefik

apiVersion: v1
kind: ServiceAccount
metadata:
  name: traefik-ingress-controller
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: traefik
  labels:
    app: traefik
spec:
  replicas: 1
  selector:
    matchLabels:
      app: traefik
  template:
    metadata:
      labels:
        app: traefik
    spec:
      serviceAccountName: traefik-ingress-controller
      containers:
        - name: traefik
          image: traefik:v3.1
          args:
            - --entryPoints.web.address=:80
            - --providers.kubernetesingress
          ports:
            - name: web
              containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: traefik
spec:
  type: LoadBalancer
  selector:
    app: traefik
  ports:
    - protocol: TCP
      port: 80
      name: web
      targetPort: 80

Whoami

apiVersion: apps/v1
kind: Deployment
metadata:
  name: whoami
  labels:
    app: traefiklabs
    name: whoami
spec:
  replicas: 2
  selector:
    matchLabels:
      app: traefiklabs
      task: whoami
  template:
    metadata:
      labels:
        app: traefiklabs
        task: whoami
    spec:
      containers:
        - name: whoami
          image: traefik/whoami
          ports:
            - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: whoami
spec:
  ports:
    - name: http
      port: 80
  selector:
    app: traefiklabs
    task: whoami

Annotations

Referencing resources in annotations

In an annotation, when referencing a resource defined by another provider, the provider namespace syntax must be used.

On Ingress

traefik.ingress.kubernetes.io/router.entrypoints

See entry points for more information.

traefik.ingress.kubernetes.io/router.entrypoints: ep1,ep2

traefik.ingress.kubernetes.io/router.middlewares

See middlewares and middlewares overview for more information.

traefik.ingress.kubernetes.io/router.middlewares: auth@file,default-prefix@kubernetescrd

traefik.ingress.kubernetes.io/router.priority

See priority for more information.

traefik.ingress.kubernetes.io/router.priority: "42"

traefik.ingress.kubernetes.io/router.pathmatcher

Overrides the default router rule type used for a path. Only path-related matcher name can be specified: Path, PathPrefix.

Default PathPrefix

traefik.ingress.kubernetes.io/router.pathmatcher: Path

traefik.ingress.kubernetes.io/router.tls

See tls for more information.

traefik.ingress.kubernetes.io/router.tls: "true"

traefik.ingress.kubernetes.io/router.tls.certresolver

See certResolver for more information.

traefik.ingress.kubernetes.io/router.tls.certresolver: myresolver

traefik.ingress.kubernetes.io/router.tls.domains.n.main

See domains for more information.

traefik.ingress.kubernetes.io/router.tls.domains.0.main: example.org

traefik.ingress.kubernetes.io/router.tls.domains.n.sans

See domains for more information.

traefik.ingress.kubernetes.io/router.tls.domains.0.sans: test.example.org,dev.example.org

traefik.ingress.kubernetes.io/router.tls.options

See options for more information.

traefik.ingress.kubernetes.io/router.tls.options: foobar@file

On Service

traefik.ingress.kubernetes.io/service.nativelb

Controls, when creating the load-balancer, whether the LB’s children are directly the pods IPs or if the only child is the Kubernetes Service clusterIP. The Kubernetes Service itself does load-balance to the pods. Please note that, by default, Traefik reuses the established connections to the backends for performance purposes. This can prevent the requests load balancing between the replicas from behaving as one would expect when the option is set. By default, NativeLB is false.

traefik.ingress.kubernetes.io/service.nativelb: "true"

traefik.ingress.kubernetes.io/service.nodeportlb

Controls, when creating the load-balancer, whether the LB’s children are directly the nodes internal IPs using the nodePort when the service type is NodePort. It allows services to be reachable when Traefik runs externally from the Kubernetes cluster but within the same network of the nodes. By default, NodePortLB is false.

traefik.ingress.kubernetes.io/service.nodeportlb: "true"

traefik.ingress.kubernetes.io/service.serversscheme

Overrides the default scheme.

traefik.ingress.kubernetes.io/service.serversscheme: h2c

traefik.ingress.kubernetes.io/service.serverstransport

See ServersTransport for more information.

traefik.ingress.kubernetes.io/service.serverstransport: foobar@file

traefik.ingress.kubernetes.io/service.passhostheader

See pass Host header for more information.

traefik.ingress.kubernetes.io/service.passhostheader: "true"

traefik.ingress.kubernetes.io/service.sticky.cookie

See sticky sessions for more information.

traefik.ingress.kubernetes.io/service.sticky.cookie: "true"

traefik.ingress.kubernetes.io/service.sticky.cookie.name

See sticky sessions for more information.

traefik.ingress.kubernetes.io/service.sticky.cookie.name: foobar

traefik.ingress.kubernetes.io/service.sticky.cookie.secure

See sticky sessions for more information.

traefik.ingress.kubernetes.io/service.sticky.cookie.secure: "true"

traefik.ingress.kubernetes.io/service.sticky.cookie.samesite

See sticky sessions for more information.

traefik.ingress.kubernetes.io/service.sticky.cookie.samesite: "none"

traefik.ingress.kubernetes.io/service.sticky.cookie.httponly

See sticky sessions for more information.

traefik.ingress.kubernetes.io/service.sticky.cookie.httponly: "true"

traefik.ingress.kubernetes.io/service.sticky.cookie.maxage

See sticky sessions for more information.

traefik.ingress.kubernetes.io/service.sticky.cookie.maxage: 42

Path Types on Kubernetes 1.18+

If the Kubernetes cluster version is 1.18+, the new pathType property can be leveraged to define the rules matchers:

• Exact: This path type forces the rule matcher to Path
• Prefix: This path type forces the rule matcher to PathPrefix

Please see this documentation for more information.

Multiple Matches

In the case of multiple matches, Traefik will not ensure the priority of a Path matcher over a PathPrefix matcher, as stated in this documentation.

TLS

Enabling TLS via HTTP Options on Entrypoint

TLS can be enabled through the HTTP options of an Entrypoint:

CLI

# Static configuration
--entryPoints.websecure.address=:443
--entryPoints.websecure.http.tls

File (YAML)

# Static configuration
entryPoints:
  websecure:
    address: ':443'
    http:
      tls: {}

File (TOML)

# Static configuration
[entryPoints.websecure]
  address = ":443"
    [entryPoints.websecure.http.tls]

This way, any Ingress attached to this Entrypoint will have TLS termination by default.

Configuring Kubernetes Ingress Controller with TLS on Entrypoint

RBAC

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: traefik-ingress-controller
rules:
  - apiGroups:
      - ""
    resources:
      - services
      - secrets
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - discovery.k8s.io
    resources:
      - endpointslices
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io
    resources:
      - ingresses
      - ingressclasses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io
    resources:
      - ingresses/status
    verbs:
      - update
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: traefik-ingress-controller
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: traefik-ingress-controller
subjects:
  - kind: ServiceAccount
    name: traefik-ingress-controller
    namespace: default

Ingress

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myingress
  annotations:
    traefik.ingress.kubernetes.io/router.entrypoints: websecure
spec:
  rules:
    - host: example.com
      http:
        paths:
          - path: /bar
            pathType: Exact
            backend:
              service:
                name:  whoami
                port:
                  number: 80
          - path: /foo
            pathType: Exact
            backend:
              service:
                name:  whoami
                port:
                  number: 80

Traefik

apiVersion: v1
kind: ServiceAccount
metadata:
  name: traefik-ingress-controller
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: traefik
  labels:
    app: traefik
spec:
  replicas: 1
  selector:
    matchLabels:
      app: traefik
  template:
    metadata:
      labels:
        app: traefik
    spec:
      serviceAccountName: traefik-ingress-controller
      containers:
        - name: traefik
          image: traefik:v3.1
          args:
            - --entryPoints.websecure.address=:443
            - --entryPoints.websecure.http.tls
            - --providers.kubernetesingress
          ports:
            - name: websecure
              containerPort: 443
---
apiVersion: v1
kind: Service
metadata:
  name: traefik
spec:
  type: LoadBalancer
  selector:
    app: traefik
  ports:
    - protocol: TCP
      port: 443
      name: websecure
      targetPort: 443

Whoami

apiVersion: apps/v1
kind: Deployment
metadata:
  name: whoami
  labels:
    app: traefiklabs
    name: whoami
spec:
  replicas: 2
  selector:
    matchLabels:
      app: traefiklabs
      task: whoami
  template:
    metadata:
      labels:
        app: traefiklabs
        task: whoami
    spec:
      containers:
        - name: whoami
          image: traefik/whoami
          ports:
            - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: whoami
spec:
  ports:
    - name: http
      port: 80
  selector:
    app: traefiklabs
    task: whoami

Enabling TLS via Annotations

To enable TLS on the underlying router created from an Ingress, one should configure it through annotations:

traefik.ingress.kubernetes.io/router.tls: "true"

For more options, please refer to the available annotations.

Configuring Kubernetes Ingress Controller with TLS

RBAC

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: traefik-ingress-controller
rules:
  - apiGroups:
      - ""
    resources:
      - services
      - secrets
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - discovery.k8s.io
    resources:
      - endpointslices
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io
    resources:
      - ingresses
      - ingressclasses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io
    resources:
      - ingresses/status
    verbs:
      - update
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: traefik-ingress-controller
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: traefik-ingress-controller
subjects:
  - kind: ServiceAccount
    name: traefik-ingress-controller
    namespace: default

Ingress

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myingress
  annotations:
    traefik.ingress.kubernetes.io/router.entrypoints: websecure
    traefik.ingress.kubernetes.io/router.tls: true
spec:
  rules:
    - host: example.com
      http:
        paths:
          - path: /bar
            pathType: Exact
            backend:
              service:
                name:  whoami
                port:
                  number: 80
          - path: /foo
            pathType: Exact
            backend:
              service:
                name:  whoami
                port:
                  number: 80

Traefik

apiVersion: v1
kind: ServiceAccount
metadata:
  name: traefik-ingress-controller
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: traefik
  labels:
    app: traefik
spec:
  replicas: 1
  selector:
    matchLabels:
      app: traefik
  template:
    metadata:
      labels:
        app: traefik
    spec:
      serviceAccountName: traefik-ingress-controller
      containers:
        - name: traefik
          image: traefik:v3.1
          args:
            - --entryPoints.websecure.address=:443
            - --providers.kubernetesingress
          ports:
            - name: websecure
              containerPort: 443
---
apiVersion: v1
kind: Service
metadata:
  name: traefik
spec:
  type: LoadBalancer
  selector:
    app: traefik
  ports:
    - protocol: TCP
      port: 443
      name: websecure
      targetPort: 443

Whoami

apiVersion: apps/v1
kind: Deployment
metadata:
  name: whoami
  labels:
    app: traefiklabs
    name: whoami
spec:
  replicas: 2
  selector:
    matchLabels:
      app: traefiklabs
      task: whoami
  template:
    metadata:
      labels:
        app: traefiklabs
        task: whoami
    spec:
      containers:
        - name: whoami
          image: traefik/whoami
          ports:
            - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: whoami
spec:
  ports:
    - name: http
      port: 80
  selector:
    app: traefiklabs
    task: whoami

Certificates Management

Using a secret

Ingress

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
  # Only selects which certificate(s) should be loaded from the secret, in order to terminate TLS.
  # Doesn't enable TLS for that ingress (hence for the underlying router).
  # Please see the TLS annotations on ingress made for that purpose.
  tls:
  - secretName: supersecret

Secret

apiVersion: v1
kind: Secret
metadata:
  name: supersecret
data:
  tls.crt: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCi0tLS0tRU5EIENFUlRJRklDQVRFLS0tLS0=
  tls.key: LS0tLS1CRUdJTiBQUklWQVRFIEtFWS0tLS0tCi0tLS0tRU5EIFBSSVZBVEUgS0VZLS0tLS0=

TLS certificates can be managed in Secrets objects.

Info

Only TLS certificates provided by users can be stored in Kubernetes Secrets. Let’s Encrypt certificates cannot be managed in Kubernetes Secrets yet.

Communication Between Traefik and Pods

Routing directly to Kubernetes services

To route directly to the Kubernetes service, one can use the traefik.ingress.kubernetes.io/service.nativelb annotation on the Kubernetes service. It controls, when creating the load-balancer, whether the LB’s children are directly the pods IPs or if the only child is the Kubernetes Service clusterIP.

One alternative is to use an ExternalName service to forward requests to the Kubernetes service through DNS. To do so, one must allow external name services.

Traefik automatically requests endpoint information based on the service provided in the ingress spec. Although Traefik will connect directly to the endpoints (pods), it still checks the service port to see if TLS communication is required.

There are 3 ways to configure Traefik to use HTTPS to communicate with pods:

1. If the service port defined in the ingress spec is 443 (note that you can still use targetPort to use a different port on your pod).
2. If the service port defined in the ingress spec has a name that starts with https (such as https-api, https-web or just https).
3. If the service spec includes the annotation traefik.ingress.kubernetes.io/service.serversscheme: https.

If either of those configuration options exist, then the backend communication protocol is assumed to be TLS, and will connect via TLS automatically.

Info

Please note that by enabling TLS communication between traefik and your pods, you will have to have trusted certificates that have the proper trust chain and IP subject name. If this is not an option, you may need to skip TLS certificate verification. See the insecureSkipVerify setting for more details.

Global Default Backend Ingresses

Ingresses can be created that look like the following:

Ingress

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
 name: cheese
spec:
  defaultBackend:
    service:
      name: stilton
      port:
        number: 80

This ingress follows the Global Default Backend property of ingresses. This will allow users to create a “default router” that will match all unmatched requests.

Info

Due to Traefik’s use of priorities, you may have to set this ingress priority lower than other ingresses in your environment, to avoid this global ingress from satisfying requests that could match other ingresses.

To do this, use the traefik.ingress.kubernetes.io/router.priority annotation (as seen in Annotations on Ingress) on your ingresses accordingly.

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