# Kubernetes Ingress Controller This guide explains how to use Træfɪk as an Ingress controller in a Kubernetes cluster. If you are not familiar with Ingresses in Kubernetes you might want to read the [Kubernetes user guide](http://kubernetes.io/docs/user-guide/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](http://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. 2. The `kubectl` binary should be [installed on your workstation](http://kubernetes.io/docs/getting-started-guides/minikube/#download-kubectl). ## Deploy Træfɪk We are going to deploy Træfɪk with a [Deployment](http://kubernetes.io/docs/user-guide/deployments/), as this will allow you to easily roll out config changes or update the image. ```yaml 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: terminationGracePeriodSeconds: 60 containers: - image: traefik name: traefik-ingress-lb resources: limits: cpu: 200m memory: 30Mi requests: cpu: 100m memory: 20Mi ports: - containerPort: 80 hostPort: 80 - containerPort: 8080 args: - --web - --kubernetes ``` [examples/k8s/traefik.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/traefik.yaml) > notice that we binding port 80 on the Træfɪk container to port 80 on the host. > With a multi node cluster we might expose Træfɪk with a NodePort or LoadBalancer service > and run more than 1 replica of Træfɪk for high availability. To deploy Træfɪk to your cluster start by submitting the deployment to the cluster with `kubectl`: ```sh kubectl apply -f examples/k8s/traefik.yaml ``` ### Check the deployment Now lets check if our deployment was successful. Start by listing the pods in the `kube-system` namespace: ```sh $kubectl --namespace=kube-system get pods 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 to Kubernetes it has launched a pod, and it is now running. _It might take a few moments for kubernetes to pull the Træfɪk image and start the container._ > 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 Træfɪk on port 80 of your minikube instance. ```sh curl $(minikube ip) 404 page not found ``` > We expect to see a 404 response here as we haven't yet given Træfɪk any configuration. ## Submitting An Ingress to the cluster. Lets start by creating a Service and an Ingress that will expose the [Træfɪk Web UI](https://github.com/containous/traefik#web-ui). ```yaml apiVersion: v1 kind: Service metadata: name: traefik-web-ui namespace: kube-system spec: selector: k8s-app: traefik-ingress-lb ports: - port: 80 targetPort: 8080 --- apiVersion: extensions/v1beta1 kind: Ingress metadata: name: traefik-web-ui namespace: kube-system spec: rules: - host: traefik-ui.local http: paths: - backend: serviceName: traefik-web-ui servicePort: 80 ``` [examples/k8s/ui.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/ui.yaml) ```sh kubectl apply -f examples/k8s/ui.yaml ``` Now lets setup an entry in our /etc/hosts file to route `traefik-ui.local` to our cluster. > In production you would want to set up real dns entries. > You can get the ip address of your minikube instance by running `minikube ip` ``` echo "$(minikube ip) traefik-ui.local" | sudo tee -a /etc/hosts ``` We should now be able to visit [traefik-ui.local](http://traefik-ui.local) in the browser and view the Træfɪk Web UI. ## Name based routing In this example we are going to setup websites for 3 of the United Kingdoms best loved cheeses, Cheddar, Stilton and Wensleydale. First lets start by launching the 3 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 resources: requests: cpu: 100m memory: 50Mi limits: cpu: 100m memory: 50Mi 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 resources: requests: cpu: 100m memory: 50Mi limits: cpu: 100m memory: 50Mi 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 resources: requests: cpu: 100m memory: 50Mi limits: cpu: 100m memory: 50Mi ports: - containerPort: 80 ``` [examples/k8s/cheese-deployments.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/cheese-deployments.yaml) ```sh kubectl apply -f 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 spec: ports: - name: http targetPort: 80 port: 80 selector: app: cheese task: wensleydale ``` [examples/k8s/cheese-services.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/cheese-services.yaml) ```sh kubectl apply -f examples/k8s/cheese-services.yaml ``` Now we can submit an ingress for the cheese websites. ```yaml apiVersion: extensions/v1beta1 kind: Ingress metadata: name: cheese spec: rules: - host: stilton.local http: paths: - path: / backend: serviceName: stilton servicePort: http - host: cheddar.local http: paths: - path: / backend: serviceName: cheddar servicePort: http - host: wensleydale.local 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) > Notice that we list each hostname, and add a backend service. ```sh kubectl apply -f examples/k8s/cheese-ingress.yaml ``` Now visit the [Træfɪk dashboard](http://traefik-ui.local/) 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. ```sh echo "$(minikube ip) stilton.local cheddar.local wensleydale.local" | sudo tee -a /etc/hosts ``` * [Stilton](http://stilton.local/) * [Cheddar](http://cheddar.local/) * [Wensleydale](http://wensleydale.local/) ## Path based routing Now lets suppose that our fictional client has decided that while they are super happy about our cheesy web design, when they asked for 3 websites they had not really bargained on having to buy 3 domain names. No problem, we say, why don't we reconfigure the sites to host all 3 under one domain. ```yaml apiVersion: extensions/v1beta1 kind: Ingress metadata: name: cheeses annotations: traefik.frontend.rule.type: pathprefixstrip spec: rules: - host: cheeses.local http: paths: - path: /stilton backend: serviceName: stilton servicePort: http - path: /cheddar backend: serviceName: cheddar servicePort: http - path: /wensleydale backend: serviceName: wensleydale servicePort: http ``` [examples/k8s/cheeses-ingress.yaml](https://github.com/containous/traefik/tree/master/examples/k8s/cheeses-ingress.yaml) > Notice that we are configuring Træfɪk to strip the prefix from the url path > with the `traefik.frontend.rule.type` annotation so that we can use > the containers from the previous example without modification. ```sh kubectl apply -f examples/k8s/cheeses-ingress.yaml ``` ```sh echo "$(minikube ip) cheeses.local" | sudo tee -a /etc/hosts ``` You should now be able to visit the websites in your browser. * [cheeses.local/stilton](http://cheeses.local/stilton/) * [cheeses.local/cheddar](http://cheeses.local/cheddar/) * [cheeses.local/wensleydale](http://cheeses.local/wensleydale/)