803 lines
23 KiB
Markdown
803 lines
23 KiB
Markdown
# Kubernetes Ingress Controller
|
|
|
|
This guide explains how to use Træfik as an Ingress controller for a Kubernetes cluster.
|
|
|
|
If you are not familiar with Ingresses in Kubernetes you might want to read the [Kubernetes user guide](https://kubernetes.io/docs/concepts/services-networking/ingress/)
|
|
|
|
The config files used in this guide can be found in the [examples directory](https://github.com/containous/traefik/tree/master/examples/k8s)
|
|
|
|
## Prerequisites
|
|
|
|
1. A working Kubernetes cluster. If you want to follow along with this guide, you should setup [minikube](https://kubernetes.io/docs/getting-started-guides/minikube/) on your machine, as it is the quickest way to get a local Kubernetes cluster setup for experimentation and development.
|
|
|
|
!!! note
|
|
The guide is likely not fully adequate for a production-ready setup.
|
|
|
|
2. The `kubectl` binary should be [installed on your workstation](https://kubernetes.io/docs/getting-started-guides/minikube/#download-kubectl).
|
|
|
|
### Role Based Access Control configuration (Kubernetes 1.6+ only)
|
|
|
|
Kubernetes introduces [Role Based Access Control (RBAC)](https://kubernetes.io/docs/admin/authorization/rbac/) in 1.6+ to allow fine-grained control of Kubernetes resources and API.
|
|
|
|
If your cluster is configured with RBAC, you will need to authorize Træfik to use the Kubernetes API. There are two ways to set up the proper permission: Via namespace-specific RoleBindings or a single, global ClusterRoleBinding.
|
|
|
|
RoleBindings per namespace enable to restrict granted permissions to the very namespaces only that Træfik is watching over, thereby following the least-privileges principle. This is the preferred approach if Træfik is not supposed to watch all namespaces, and the set of namespaces does not change dynamically. Otherwise, a single ClusterRoleBinding must be employed.
|
|
|
|
!!! note
|
|
RoleBindings per namespace are available in Træfik 1.5 and later. Please use ClusterRoleBindings for older versions.
|
|
|
|
For the sake of simplicity, this guide will use a ClusterRoleBinding:
|
|
|
|
```yaml
|
|
---
|
|
kind: ClusterRole
|
|
apiVersion: rbac.authorization.k8s.io/v1beta1
|
|
metadata:
|
|
name: traefik-ingress-controller
|
|
rules:
|
|
- apiGroups:
|
|
- ""
|
|
resources:
|
|
- services
|
|
- endpoints
|
|
- secrets
|
|
verbs:
|
|
- get
|
|
- list
|
|
- watch
|
|
- apiGroups:
|
|
- extensions
|
|
resources:
|
|
- ingresses
|
|
verbs:
|
|
- get
|
|
- list
|
|
- watch
|
|
---
|
|
kind: ClusterRoleBinding
|
|
apiVersion: rbac.authorization.k8s.io/v1beta1
|
|
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: kube-system
|
|
```
|
|
|
|
[examples/k8s/traefik-rbac.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/traefik-rbac.yaml)
|
|
|
|
```shell
|
|
kubectl apply -f https://raw.githubusercontent.com/containous/traefik/master/examples/k8s/traefik-rbac.yaml
|
|
```
|
|
|
|
For namespaced restrictions, one RoleBinding is required per watched namespace along with a corresponding configuration of Træfik's `kubernetes.namespaces` parameter.
|
|
|
|
## Deploy Træfik using a Deployment or DaemonSet
|
|
|
|
It is possible to use Træfik with a [Deployment](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/) or a [DaemonSet](https://kubernetes.io/docs/concepts/workloads/controllers/daemonset/) object,
|
|
whereas both options have their own pros and cons:
|
|
|
|
- The scalability is much better when using a Deployment, because you will have a Single-Pod-per-Node model when using the DeaemonSet.
|
|
- It is possible to exclusively run a Service on a dedicated set of machines using taints and tolerations with a DaemonSet.
|
|
- On the other hand the DaemonSet allows you to access any Node directly on Port 80 and 443, where you have to setup a [Service](https://kubernetes.io/docs/concepts/services-networking/service/) object with a Deployment.
|
|
|
|
The Deployment objects looks like this:
|
|
|
|
```yaml
|
|
---
|
|
apiVersion: v1
|
|
kind: ServiceAccount
|
|
metadata:
|
|
name: traefik-ingress-controller
|
|
namespace: kube-system
|
|
---
|
|
kind: Deployment
|
|
apiVersion: extensions/v1beta1
|
|
metadata:
|
|
name: traefik-ingress-controller
|
|
namespace: kube-system
|
|
labels:
|
|
k8s-app: traefik-ingress-lb
|
|
spec:
|
|
replicas: 1
|
|
selector:
|
|
matchLabels:
|
|
k8s-app: traefik-ingress-lb
|
|
template:
|
|
metadata:
|
|
labels:
|
|
k8s-app: traefik-ingress-lb
|
|
name: traefik-ingress-lb
|
|
spec:
|
|
serviceAccountName: traefik-ingress-controller
|
|
terminationGracePeriodSeconds: 60
|
|
containers:
|
|
- image: traefik
|
|
name: traefik-ingress-lb
|
|
args:
|
|
- --api
|
|
- --kubernetes
|
|
---
|
|
kind: Service
|
|
apiVersion: v1
|
|
metadata:
|
|
name: traefik-ingress-service
|
|
namespace: kube-system
|
|
spec:
|
|
selector:
|
|
k8s-app: traefik-ingress-lb
|
|
ports:
|
|
- protocol: TCP
|
|
port: 80
|
|
name: web
|
|
- protocol: TCP
|
|
port: 8080
|
|
name: admin
|
|
type: NodePort
|
|
```
|
|
|
|
[examples/k8s/traefik-deployment.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/traefik-deployment.yaml)
|
|
|
|
!!! note
|
|
The Service will expose two NodePorts which allow access to the ingress and the web interface.
|
|
|
|
The DaemonSet objects looks not much different:
|
|
|
|
```yaml
|
|
---
|
|
apiVersion: v1
|
|
kind: ServiceAccount
|
|
metadata:
|
|
name: traefik-ingress-controller
|
|
namespace: kube-system
|
|
---
|
|
kind: DaemonSet
|
|
apiVersion: extensions/v1beta1
|
|
metadata:
|
|
name: traefik-ingress-controller
|
|
namespace: kube-system
|
|
labels:
|
|
k8s-app: traefik-ingress-lb
|
|
spec:
|
|
template:
|
|
metadata:
|
|
labels:
|
|
k8s-app: traefik-ingress-lb
|
|
name: traefik-ingress-lb
|
|
spec:
|
|
serviceAccountName: traefik-ingress-controller
|
|
terminationGracePeriodSeconds: 60
|
|
hostNetwork: true
|
|
containers:
|
|
- image: traefik
|
|
name: traefik-ingress-lb
|
|
ports:
|
|
- name: http
|
|
containerPort: 80
|
|
hostPort: 80
|
|
- name: admin
|
|
containerPort: 8080
|
|
securityContext:
|
|
privileged: true
|
|
args:
|
|
- --api
|
|
- --kubernetes
|
|
- --logLevel=INFO
|
|
---
|
|
kind: Service
|
|
apiVersion: v1
|
|
metadata:
|
|
name: traefik-ingress-service
|
|
namespace: kube-system
|
|
spec:
|
|
selector:
|
|
k8s-app: traefik-ingress-lb
|
|
ports:
|
|
- protocol: TCP
|
|
port: 80
|
|
name: web
|
|
- protocol: TCP
|
|
port: 8080
|
|
name: admin
|
|
type: NodePort
|
|
```
|
|
|
|
[examples/k8s/traefik-ds.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/traefik-ds.yaml)
|
|
|
|
To deploy Træfik to your cluster start by submitting one of the YAML files to the cluster with `kubectl`:
|
|
|
|
```shell
|
|
kubectl apply -f https://raw.githubusercontent.com/containous/traefik/master/examples/k8s/traefik-deployment.yaml
|
|
```
|
|
|
|
```shell
|
|
kubectl apply -f https://raw.githubusercontent.com/containous/traefik/master/examples/k8s/traefik-ds.yaml
|
|
```
|
|
|
|
There are some significant differences between using Deployments and DaemonSets:
|
|
|
|
- The Deployment has easier up and down scaling possibilities.
|
|
It can implement full pod lifecycle and supports rolling updates from Kubernetes 1.2.
|
|
At least one Pod is needed to run the Deployment.
|
|
- The DaemonSet automatically scales to all nodes that meets a specific selector and guarantees to fill nodes one at a time.
|
|
Rolling updates are fully supported from Kubernetes 1.7 for DaemonSets as well.
|
|
|
|
### Check the Pods
|
|
|
|
Now lets check if our command was successful.
|
|
|
|
Start by listing the pods in the `kube-system` namespace:
|
|
|
|
```shell
|
|
kubectl --namespace=kube-system get pods
|
|
```
|
|
|
|
```shell
|
|
NAME READY STATUS RESTARTS AGE
|
|
kube-addon-manager-minikubevm 1/1 Running 0 4h
|
|
kubernetes-dashboard-s8krj 1/1 Running 0 4h
|
|
traefik-ingress-controller-678226159-eqseo 1/1 Running 0 7m
|
|
```
|
|
|
|
You should see that after submitting the Deployment or DaemonSet to Kubernetes it has launched a Pod, and it is now running.
|
|
_It might take a few moments for kubernetes to pull the Træfik image and start the container._
|
|
|
|
!!! note
|
|
You could also check the deployment with the Kubernetes dashboard, run
|
|
`minikube dashboard` to open it in your browser, then choose the `kube-system`
|
|
namespace from the menu at the top right of the screen.
|
|
|
|
You should now be able to access Træfik on port 80 of your Minikube instance when using the DaemonSet:
|
|
|
|
```shell
|
|
curl $(minikube ip)
|
|
```
|
|
|
|
```shell
|
|
404 page not found
|
|
```
|
|
|
|
If you decided to use the deployment, then you need to target the correct NodePort, which can be seen when you execute `kubectl get services --namespace=kube-system`.
|
|
|
|
```shell
|
|
curl $(minikube ip):<NODEPORT>
|
|
```
|
|
|
|
```shell
|
|
404 page not found
|
|
```
|
|
|
|
!!! note
|
|
We expect to see a 404 response here as we haven't yet given Træfik any configuration.
|
|
|
|
All further examples below assume a DaemonSet installation. Deployment users will need to append the NodePort when constructing requests.
|
|
|
|
## Deploy Træfik using Helm Chart
|
|
|
|
!!! note
|
|
The Helm Chart is maintained by the community, not the Traefik project maintainers.
|
|
|
|
Instead of installing Træfik via Kubernetes object directly, you can also use the Træfik Helm chart.
|
|
|
|
Install the Træfik chart by:
|
|
|
|
```shell
|
|
helm install stable/traefik
|
|
```
|
|
|
|
For more information, check out [the documentation](https://github.com/kubernetes/charts/tree/master/stable/traefik).
|
|
|
|
## Submitting an Ingress to the Cluster
|
|
|
|
Lets start by creating a Service and an Ingress that will expose the [Træfik Web UI](https://github.com/containous/traefik#web-ui).
|
|
|
|
```yaml
|
|
apiVersion: v1
|
|
kind: Service
|
|
metadata:
|
|
name: traefik-web-ui
|
|
namespace: kube-system
|
|
spec:
|
|
selector:
|
|
k8s-app: traefik-ingress-lb
|
|
ports:
|
|
- port: 80
|
|
targetPort: 8080
|
|
---
|
|
apiVersion: extensions/v1beta1
|
|
kind: Ingress
|
|
metadata:
|
|
name: traefik-web-ui
|
|
namespace: kube-system
|
|
annotations:
|
|
kubernetes.io/ingress.class: traefik
|
|
spec:
|
|
rules:
|
|
- host: traefik-ui.minikube
|
|
http:
|
|
paths:
|
|
- backend:
|
|
serviceName: traefik-web-ui
|
|
servicePort: 80
|
|
```
|
|
|
|
[examples/k8s/ui.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/ui.yaml)
|
|
|
|
```shell
|
|
kubectl apply -f https://raw.githubusercontent.com/containous/traefik/master/examples/k8s/ui.yaml
|
|
```
|
|
|
|
Now lets setup an entry in our `/etc/hosts` file to route `traefik-ui.minikube` to our cluster.
|
|
|
|
In production you would want to set up real DNS entries.
|
|
You can get the IP address of your minikube instance by running `minikube ip`:
|
|
|
|
```shell
|
|
echo "$(minikube ip) traefik-ui.minikube" | sudo tee -a /etc/hosts
|
|
```
|
|
|
|
We should now be able to visit [traefik-ui.minikube](http://traefik-ui.minikube) in the browser and view the Træfik web UI.
|
|
|
|
## Basic Authentication
|
|
|
|
It's possible to protect access to Traefik through basic authentication. (See the [Kubernetes Ingress](/configuration/backends/kubernetes) configuration page for syntactical details and restrictions.)
|
|
|
|
### Creating the Secret
|
|
|
|
A. Use `htpasswd` to create a file containing the username and the base64-encoded password:
|
|
|
|
```shell
|
|
htpasswd -c ./auth myusername
|
|
```
|
|
|
|
You will be prompted for a password which you will have to enter twice.
|
|
`htpasswd` will create a file with the following:
|
|
|
|
```shell
|
|
cat auth
|
|
```
|
|
|
|
```shell
|
|
myusername:$apr1$78Jyn/1K$ERHKVRPPlzAX8eBtLuvRZ0
|
|
```
|
|
|
|
B. Now use `kubectl` to create a secret in the `monitoring` namespace using the file created by `htpasswd`.
|
|
|
|
```shell
|
|
kubectl create secret generic mysecret --from-file auth --namespace=monitoring
|
|
```
|
|
|
|
!!! note
|
|
Secret must be in same namespace as the Ingress object.
|
|
|
|
C. Attach the following annotations to the Ingress object:
|
|
|
|
- `ingress.kubernetes.io/auth-type: "basic"`
|
|
- `ingress.kubernetes.io/auth-secret: "mysecret"`
|
|
|
|
They specify basic authentication and reference the Secret `mysecret` containing the credentials.
|
|
|
|
Following is a full Ingress example based on Prometheus:
|
|
|
|
```yaml
|
|
apiVersion: extensions/v1beta1
|
|
kind: Ingress
|
|
metadata:
|
|
name: prometheus-dashboard
|
|
namespace: monitoring
|
|
annotations:
|
|
kubernetes.io/ingress.class: traefik
|
|
ingress.kubernetes.io/auth-type: "basic"
|
|
ingress.kubernetes.io/auth-secret: "mysecret"
|
|
spec:
|
|
rules:
|
|
- host: dashboard.prometheus.example.com
|
|
http:
|
|
paths:
|
|
- backend:
|
|
serviceName: prometheus
|
|
servicePort: 9090
|
|
```
|
|
|
|
You can apply the example as following:
|
|
|
|
```shell
|
|
kubectl create -f prometheus-ingress.yaml -n monitoring
|
|
```
|
|
|
|
## Name-based Routing
|
|
|
|
In this example we are going to setup websites for three of the United Kingdoms best loved cheeses: Cheddar, Stilton, and Wensleydale.
|
|
|
|
First lets start by launching the pods for the cheese websites.
|
|
|
|
```yaml
|
|
---
|
|
kind: Deployment
|
|
apiVersion: extensions/v1beta1
|
|
metadata:
|
|
name: stilton
|
|
labels:
|
|
app: cheese
|
|
cheese: stilton
|
|
spec:
|
|
replicas: 2
|
|
selector:
|
|
matchLabels:
|
|
app: cheese
|
|
task: stilton
|
|
template:
|
|
metadata:
|
|
labels:
|
|
app: cheese
|
|
task: stilton
|
|
version: v0.0.1
|
|
spec:
|
|
containers:
|
|
- name: cheese
|
|
image: errm/cheese:stilton
|
|
ports:
|
|
- containerPort: 80
|
|
---
|
|
kind: Deployment
|
|
apiVersion: extensions/v1beta1
|
|
metadata:
|
|
name: cheddar
|
|
labels:
|
|
app: cheese
|
|
cheese: cheddar
|
|
spec:
|
|
replicas: 2
|
|
selector:
|
|
matchLabels:
|
|
app: cheese
|
|
task: cheddar
|
|
template:
|
|
metadata:
|
|
labels:
|
|
app: cheese
|
|
task: cheddar
|
|
version: v0.0.1
|
|
spec:
|
|
containers:
|
|
- name: cheese
|
|
image: errm/cheese:cheddar
|
|
ports:
|
|
- containerPort: 80
|
|
---
|
|
kind: Deployment
|
|
apiVersion: extensions/v1beta1
|
|
metadata:
|
|
name: wensleydale
|
|
labels:
|
|
app: cheese
|
|
cheese: wensleydale
|
|
spec:
|
|
replicas: 2
|
|
selector:
|
|
matchLabels:
|
|
app: cheese
|
|
task: wensleydale
|
|
template:
|
|
metadata:
|
|
labels:
|
|
app: cheese
|
|
task: wensleydale
|
|
version: v0.0.1
|
|
spec:
|
|
containers:
|
|
- name: cheese
|
|
image: errm/cheese:wensleydale
|
|
ports:
|
|
- containerPort: 80
|
|
```
|
|
|
|
[examples/k8s/cheese-deployments.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/cheese-deployments.yaml)
|
|
|
|
```shell
|
|
kubectl apply -f https://raw.githubusercontent.com/containous/traefik/master/examples/k8s/cheese-deployments.yaml
|
|
```
|
|
|
|
Next we need to setup a Service for each of the cheese pods.
|
|
|
|
```yaml
|
|
---
|
|
apiVersion: v1
|
|
kind: Service
|
|
metadata:
|
|
name: stilton
|
|
spec:
|
|
ports:
|
|
- name: http
|
|
targetPort: 80
|
|
port: 80
|
|
selector:
|
|
app: cheese
|
|
task: stilton
|
|
---
|
|
apiVersion: v1
|
|
kind: Service
|
|
metadata:
|
|
name: cheddar
|
|
spec:
|
|
ports:
|
|
- name: http
|
|
targetPort: 80
|
|
port: 80
|
|
selector:
|
|
app: cheese
|
|
task: cheddar
|
|
---
|
|
apiVersion: v1
|
|
kind: Service
|
|
metadata:
|
|
name: wensleydale
|
|
annotations:
|
|
traefik.backend.circuitbreaker: "NetworkErrorRatio() > 0.5"
|
|
spec:
|
|
ports:
|
|
- name: http
|
|
targetPort: 80
|
|
port: 80
|
|
selector:
|
|
app: cheese
|
|
task: wensleydale
|
|
```
|
|
|
|
!!! note
|
|
We also set a [circuit breaker expression](/basics/#backends) for one of the backends by setting the `traefik.backend.circuitbreaker` annotation on the service.
|
|
|
|
[examples/k8s/cheese-services.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/cheese-services.yaml)
|
|
|
|
```shell
|
|
kubectl apply -f https://raw.githubusercontent.com/containous/traefik/master/examples/k8s/cheese-services.yaml
|
|
```
|
|
|
|
Now we can submit an ingress for the cheese websites.
|
|
|
|
```yaml
|
|
apiVersion: extensions/v1beta1
|
|
kind: Ingress
|
|
metadata:
|
|
name: cheese
|
|
annotations:
|
|
kubernetes.io/ingress.class: traefik
|
|
spec:
|
|
rules:
|
|
- host: stilton.minikube
|
|
http:
|
|
paths:
|
|
- path: /
|
|
backend:
|
|
serviceName: stilton
|
|
servicePort: http
|
|
- host: cheddar.minikube
|
|
http:
|
|
paths:
|
|
- path: /
|
|
backend:
|
|
serviceName: cheddar
|
|
servicePort: http
|
|
- host: wensleydale.minikube
|
|
http:
|
|
paths:
|
|
- path: /
|
|
backend:
|
|
serviceName: wensleydale
|
|
servicePort: http
|
|
```
|
|
|
|
[examples/k8s/cheese-ingress.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/cheese-ingress.yaml)
|
|
|
|
!!! note
|
|
we list each hostname, and add a backend service.
|
|
|
|
```shell
|
|
kubectl apply -f https://raw.githubusercontent.com/containous/traefik/master/examples/k8s/cheese-ingress.yaml
|
|
```
|
|
|
|
Now visit the [Træfik dashboard](http://traefik-ui.minikube/) and you should see a frontend for each host.
|
|
Along with a backend listing for each service with a server set up for each pod.
|
|
|
|
If you edit your `/etc/hosts` again you should be able to access the cheese websites in your browser.
|
|
|
|
```shell
|
|
echo "$(minikube ip) stilton.minikube cheddar.minikube wensleydale.minikube" | sudo tee -a /etc/hosts
|
|
```
|
|
|
|
- [Stilton](http://stilton.minikube/)
|
|
- [Cheddar](http://cheddar.minikube/)
|
|
- [Wensleydale](http://wensleydale.minikube/)
|
|
|
|
## Path-based Routing
|
|
|
|
Now lets suppose that our fictional client has decided that while they are super happy about our cheesy web design, when they asked for 3 websites they had not really bargained on having to buy 3 domain names.
|
|
|
|
No problem, we say, why don't we reconfigure the sites to host all 3 under one domain.
|
|
|
|
```yaml
|
|
apiVersion: extensions/v1beta1
|
|
kind: Ingress
|
|
metadata:
|
|
name: cheeses
|
|
annotations:
|
|
kubernetes.io/ingress.class: traefik
|
|
traefik.frontend.rule.type: PathPrefixStrip
|
|
spec:
|
|
rules:
|
|
- host: cheeses.minikube
|
|
http:
|
|
paths:
|
|
- path: /stilton
|
|
backend:
|
|
serviceName: stilton
|
|
servicePort: http
|
|
- path: /cheddar
|
|
backend:
|
|
serviceName: cheddar
|
|
servicePort: http
|
|
- path: /wensleydale
|
|
backend:
|
|
serviceName: wensleydale
|
|
servicePort: http
|
|
```
|
|
|
|
[examples/k8s/cheeses-ingress.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/cheeses-ingress.yaml)
|
|
|
|
!!! note
|
|
We are configuring Træfik to strip the prefix from the url path with the `traefik.frontend.rule.type` annotation so that we can use the containers from the previous example without modification.
|
|
|
|
```shell
|
|
kubectl apply -f https://raw.githubusercontent.com/containous/traefik/master/examples/k8s/cheeses-ingress.yaml
|
|
```
|
|
|
|
```shell
|
|
echo "$(minikube ip) cheeses.minikube" | sudo tee -a /etc/hosts
|
|
```
|
|
|
|
You should now be able to visit the websites in your browser.
|
|
|
|
- [cheeses.minikube/stilton](http://cheeses.minikube/stilton/)
|
|
- [cheeses.minikube/cheddar](http://cheeses.minikube/cheddar/)
|
|
- [cheeses.minikube/wensleydale](http://cheeses.minikube/wensleydale/)
|
|
|
|
## Specifying Routing Priorities
|
|
|
|
Sometimes you need to specify priority for ingress routes, especially when handling wildcard routes.
|
|
This can be done by adding the `traefik.frontend.priority` annotation, i.e.:
|
|
|
|
```yaml
|
|
apiVersion: extensions/v1beta1
|
|
kind: Ingress
|
|
metadata:
|
|
name: wildcard-cheeses
|
|
annotations:
|
|
traefik.frontend.priority: "1"
|
|
spec:
|
|
rules:
|
|
- host: *.minikube
|
|
http:
|
|
paths:
|
|
- path: /
|
|
backend:
|
|
serviceName: stilton
|
|
servicePort: http
|
|
|
|
kind: Ingress
|
|
metadata:
|
|
name: specific-cheeses
|
|
annotations:
|
|
traefik.frontend.priority: "2"
|
|
spec:
|
|
rules:
|
|
- host: specific.minikube
|
|
http:
|
|
paths:
|
|
- path: /
|
|
backend:
|
|
serviceName: stilton
|
|
servicePort: http
|
|
```
|
|
|
|
Note that priority values must be quoted to avoid numeric interpretation (which are illegal for annotations).
|
|
|
|
## Forwarding to ExternalNames
|
|
|
|
When specifying an [ExternalName](https://kubernetes.io/docs/concepts/services-networking/service/#services-without-selectors),
|
|
Træfik will forward requests to the given host accordingly and use HTTPS when the Service port matches 443.
|
|
This still requires setting up a proper port mapping on the Service from the Ingress port to the (external) Service port.
|
|
|
|
## Disable passing the Host Header
|
|
|
|
By default Træfik will pass the incoming Host header to the upstream resource.
|
|
|
|
However, there are times when you may not want this to be the case. For example, if your service is of the ExternalName type.
|
|
|
|
### Disable globally
|
|
|
|
Add the following to your TOML configuration file:
|
|
|
|
```toml
|
|
disablePassHostHeaders = true
|
|
```
|
|
|
|
### Disable per Ingress
|
|
|
|
To disable passing the Host header per ingress resource set the `traefik.frontend.passHostHeader` annotation on your ingress to `"false"`.
|
|
|
|
Here is an example definition:
|
|
|
|
```yaml
|
|
apiVersion: extensions/v1beta1
|
|
kind: Ingress
|
|
metadata:
|
|
name: example
|
|
annotations:
|
|
kubernetes.io/ingress.class: traefik
|
|
traefik.frontend.passHostHeader: "false"
|
|
spec:
|
|
rules:
|
|
- host: example.com
|
|
http:
|
|
paths:
|
|
- path: /static
|
|
backend:
|
|
serviceName: static
|
|
servicePort: https
|
|
```
|
|
|
|
And an example service definition:
|
|
|
|
```yaml
|
|
apiVersion: v1
|
|
kind: Service
|
|
metadata:
|
|
name: static
|
|
spec:
|
|
ports:
|
|
- name: https
|
|
port: 443
|
|
type: ExternalName
|
|
externalName: static.otherdomain.com
|
|
```
|
|
|
|
If you were to visit `example.com/static` the request would then be passed on to `static.otherdomain.com/static`, and `static.otherdomain.com` would receive the request with the Host header being `static.otherdomain.com`.
|
|
|
|
!!! note
|
|
The per-ingress annotation overrides whatever the global value is set to.
|
|
So you could set `disablePassHostHeaders` to `true` in your TOML configuration file and then enable passing the host header per ingress if you wanted.
|
|
|
|
## Partitioning the Ingress object space
|
|
|
|
By default, Træfik processes every Ingress objects it observes. At times, however, it may be desirable to ignore certain objects. The following sub-sections describe common use cases and how they can be handled with Træfik.
|
|
|
|
### Between Træfik and other Ingress controller implementations
|
|
|
|
Sometimes Træfik runs along other Ingress controller implementations. One such example is when both Træfik and a cloud provider Ingress controller are active.
|
|
|
|
The `kubernetes.io/ingress.class` annotation can be attached to any Ingress object in order to control whether Træfik should handle it.
|
|
|
|
If the annotation is missing, contains an empty value, or the value `traefik`, then the Træfik controller will take responsibility and process the associated Ingress object. If the annotation contains any other value (usually the name of a different Ingress controller), Træfik will ignore the object.
|
|
|
|
### Between multiple Træfik Deployments
|
|
|
|
Sometimes multiple Træfik Deployments are supposed to run concurrently. For instance, it is conceivable to have one Deployment deal with internal and another one with external traffic.
|
|
|
|
For such cases, it is advisable to classify Ingress objects through a label and configure the `labelSelector` option per each Træfik Deployment accordingly. To stick with the internal/external example above, all Ingress objects meant for internal traffic could receive a `traffic-type: internal` label while objects designated for external traffic receive a `traffic-type: external` label. The label selectors on the Træfik Deployments would then be `traffic-type=internal` and `traffic-type=external`, respectively.
|
|
|
|
## Production advice
|
|
|
|
### Resource limitations
|
|
|
|
The examples shown deliberately do not specify any [resource limitations](https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/) as there is no one size fits all.
|
|
|
|
In a production environment, however, it is important to set proper bounds, especially with regards to CPU:
|
|
|
|
- too strict and Traefik will be throttled while serving requests (as Kubernetes imposes hard quotas)
|
|
- too loose and Traefik may waste resources not available for other containers
|
|
|
|
When in doubt, you should measure your resource needs, and adjust requests and limits accordingly.
|