Pular para o conteúdo

Kubernetes

Atualizado em Ver como Markdown

Kubernetes ↗ is a container orchestration tool that is used to deploy applications onto physical or virtual machines, scale the deployment to meet traffic demands, and push updates without downtime. The Kubernetes cluster, or environment, where the application instances are running is connected internally through a private network. You can install the cloudflared daemon inside of the Kubernetes cluster in order to connect applications inside of the cluster to Cloudflare.

This guide will cover how to expose a Kubernetes service to the public Internet using a remotely-managed Cloudflare Tunnel. For the purposes of this example, we will deploy a basic web application alongside cloudflared in Google Kubernetes Engine (GKE). The same principles apply to any other Kubernetes environment (such as minikube, kubeadm, or a cloud-based Kubernetes service) where cloudflared can connect to Cloudflare's network.

Architecture

Diagram showing how a user connects to Kubernetes services through Cloudflare Tunnel

As shown in the diagram, we recommend setting up cloudflared as an adjacent deployment ↗ to the application deployments. Having a separate Kubernetes deployment for cloudflared allows you to scale cloudflared independently of the application. In the cloudflared deployment, you can spin up multiple replicas running the same Cloudflare Tunnel — there is no need to build a dedicated tunnel for each cloudflared pod. Each cloudflared replica / pod can reach all Kubernetes services in the cluster.

Once the cluster is connected to Cloudflare, you can configure Cloudflare Tunnel routes to control how cloudflared will proxy traffic to services within the cluster. For example, you may wish to publish certain Kubernetes applications to the Internet and restrict other applications to internal Cloudflare One Client users.

Prerequisites

To complete the following procedure, you will need:

1. Create a GKE cluster

To create a new Kubernetes cluster in Google Cloud:

  1. Open Google Cloud ↗ and go to Kubernetes Engine.

  2. In Clusters, select Create.

  3. Name the cluster. In this example, we will name it cloudflare-tunnel.

  4. (Optional) Choose your desired region and other cluster specifications. For this example, we will use the default specifications.

  5. Select Create.

  6. To connect to the cluster:

    1. Select the three-dot menu.
    2. Select Connect.
    3. Select Run in Cloud Shell to open a terminal in the browser.
    4. Select Authorize.
    5. Press Enter to run the pre-populated gcloud command.
    6. (Recommended) In the Cloud Shell menu, select Open Editor to launch the built-in IDE.

  7. In the Cloud Shell terminal, run the following command to check the cluster status:

    kubectl get all
    NAME                 TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   34.118.224.1   <none>        443/TCP   15m

2. Create pods for the web app

A pod represents an instance of a running process in the cluster. In this example, we will deploy the httpbin ↗ application with two pods and make the pods accessible inside the cluster at httpbin-service:80.

  1. Create a folder for your Kubernetes manifest files:

    mkdir tunnel-example

  2. Change into the directory:

    cd tunnel-example

  3. In the tunnel-example directory, create a new file called httpbin.yaml. This file defines the Kubernetes deployment for the httpbin app.

    httpbin.yamlyaml
    apiVersion: apps/v1
kind: Deployment
metadata:
  name: httpbin-deployment
  namespace: default
spec:
  replicas: 2
  selector:
    matchLabels:
      app: httpbin
  template:
    metadata:
      labels:
        app: httpbin
    spec:
      containers:
        - name: httpbin
          image: kennethreitz/httpbin:latest
          imagePullPolicy: IfNotPresent
          ports:
            - containerPort: 80

  4. Create a new httpbinsvc.yaml file. This file defines a Kubernetes service that allows other apps in the cluster (such as cloudflared) to access the set of httpbin pods.

    httpbinsvc.yamlyaml
    apiVersion: v1
kind: Service
metadata:
  name: httpbin-service
  namespace: default
spec:
  type: LoadBalancer
  selector:
    app: httpbin
  ports:
    - port: 80
      targetPort: 80

  5. Use the following command to run the application inside the cluster:

    kubectl create -f httpbin.yaml -f httpbinsvc.yaml

  6. Check the status of your deployment:

    kubectl get all
    NAME                                     READY   STATUS    RESTARTS   AGE
pod/httpbin-deployment-bc6689c5d-b5ftk   1/1     Running   0          79s
pod/httpbin-deployment-bc6689c5d-cbd9m   1/1     Running   0          79s

NAME                      TYPE           CLUSTER-IP       EXTERNAL-IP    PORT(S)        AGE
service/httpbin-service   LoadBalancer   34.118.225.147   34.75.201.60   80:31967/TCP   79s
service/kubernetes        ClusterIP      34.118.224.1     <none>         443/TCP        24h

NAME                                 READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/httpbin-deployment   2/2     2            2           79s

NAME                                           DESIRED   CURRENT   READY   AGE
replicaset.apps/httpbin-deployment-bc6689c5d   2         2         2       79s

3. Create a tunnel

To create a Cloudflare Tunnel:

  1. In the Cloudflare dashboard, go to Networking > Tunnels.

  2. Select Create a tunnel.

  3. Enter a name for your tunnel (for example, gke-tunnel).

  4. Select Create Tunnel.

  5. Choose your operating system and select Docker.

    Applications must be packaged into a containerized image before you can run it in Kubernetes. Therefore, we will use the cloudflared Docker container image to deploy the tunnel in Kubernetes.

  6. Instead of running the installation command, copy just the token value rather than the whole command. The token value is of the form eyJhIjoiNWFiNGU5Z... You will need the token for the Kubernetes manifest file.

Leave the Cloudflare Tunnel browser tab open while we focus on the Kubernetes deployment.

4. Store the tunnel token

cloudflared uses a tunnel token to run a remotely-managed Cloudflare Tunnel. You can store the tunnel token in a Kubernetes secret ↗.

  1. In GKE Cloud Shell, create a tunnel-token.yaml file with the following content. Make sure to replace <YOUR_TUNNEL_TOKEN> with your tunnel token (eyJhIjoiNWFiNGU5Z...).

    tunnel-token.yamlyaml
    apiVersion: v1
kind: Secret
metadata:
  name: tunnel-token
stringData:
  token: <YOUR_TUNNEL_TOKEN>

  2. Create the secret:

    kubectl create -f tunnel-token.yaml

  3. Check the newly created secret:

    kubectl get secrets
    NAME        TYPE     DATA   AGE
tunnel-token   Opaque   1      100s

5. Create pods for cloudflared

To run the Cloudflare Tunnel in Kubernetes:

  1. Create a Kubernetes deployment for a remotely-managed Cloudflare Tunnel:

    tunnel.yamlyaml
    apiVersion: apps/v1
kind: Deployment
metadata:
  name: cloudflared-deployment
  namespace: default
spec:
  replicas: 2
  selector:
    matchLabels:
      pod: cloudflared
  template:
    metadata:
      labels:
        pod: cloudflared
    spec:
      securityContext:
        sysctls:
          # Allows ICMP traffic (ping, traceroute) to resources behind cloudflared.
          - name: net.ipv4.ping_group_range
            value: "65532 65532"
      containers:
        - image: cloudflare/cloudflared:latest
          name: cloudflared
          env:
            # Defines an environment variable for the tunnel token.
            - name: TUNNEL_TOKEN
              valueFrom:
                secretKeyRef:
                  name: tunnel-token
                  key: token
          command:
            # Configures tunnel run parameters
            - cloudflared
            - tunnel
            - --no-autoupdate
            - --loglevel
            - info
            - --metrics
            - 0.0.0.0:2000
            - run
          livenessProbe:
            httpGet:
              # Cloudflared has a /ready endpoint which returns 200 if and only if
              # it has an active connection to Cloudflare's network.
              path: /ready
              port: 2000
            failureThreshold: 1
            initialDelaySeconds: 10
            periodSeconds: 10

  2. Deploy cloudflared to the cluster:

    kubectl create -f tunnel.yaml

    Kubernetes will install the cloudflared image on two pods and run the tunnel using the command cloudflared tunnel --no-autoupdate --loglevel info --metrics 0.0.0.0:2000 run. cloudflared will consume the tunnel token from the TUNNEL_TOKEN environment variable.

  3. Check the status of your cluster:

    kubectl get all
    NAME                                          READY   STATUS    RESTARTS   AGE
pod/cloudflared-deployment-6d5f9f9666-85l5w   1/1     Running   0          21s
pod/cloudflared-deployment-6d5f9f9666-wb96x   1/1     Running   0          21s
pod/httpbin-deployment-bc6689c5d-b5ftk        1/1     Running   0          3m36s
pod/httpbin-deployment-bc6689c5d-cbd9m        1/1     Running   0          3m36s

NAME                      TYPE           CLUSTER-IP       EXTERNAL-IP    PORT(S)        AGE
service/httpbin-service   LoadBalancer   34.118.225.147   34.75.201.60   80:31967/TCP   3m36s
service/kubernetes        ClusterIP      34.118.224.1     <none>         443/TCP        24h

NAME                                     READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/cloudflared-deployment   2/2     2            2           22s
deployment.apps/httpbin-deployment       2/2     2            2           3m37s

NAME                                                DESIRED   CURRENT   READY   AGE
replicaset.apps/cloudflared-deployment-6d5f9f9666   2         2         2       22s
replicaset.apps/httpbin-deployment-bc6689c5d        2         2         2       3m37s

You should see two cloudflared pods and two httpbin pods with a Running status. If your cloudflared pods keep restarting, check the command syntax in tunnel.yaml and make sure that the tunnel run parameters are in the correct order.

6. Verify tunnel status

To print logs for a cloudflared instance:

kubectl logs pod/cloudflared-deployment-6d5f9f9666-85l5w
2025-06-11T22:00:47Z INF Starting tunnel tunnelID=64c359b6-e111-40ec-a3a9-199c2a656613
2025-06-11T22:00:47Z INF Version 2025.6.0 (Checksum 72f233bb55199093961bf099ad62d491db58819df34b071ab231f622deff33ce)
2025-06-11T22:00:47Z INF GOOS: linux, GOVersion: go1.24.2, GoArch: amd64
2025-06-11T22:00:47Z INF Settings: map[loglevel:debug metrics:0.0.0.0:2000 no-autoupdate:true token:*****]
2025-06-11T22:00:47Z INF Generated Connector ID: aff7c4a0-85a3-4ac9-8475-1e0aa1af8d94
2025-06-11T22:00:47Z DBG Fetched protocol: quic
2025-06-11T22:00:47Z INF Initial protocol quic
...

7. Add a tunnel route

Now that the tunnel is up and running, we can route the httpbin service through the tunnel.

  1. In the Cloudflare dashboard, go to Networking > Tunnels and select your tunnel.

  2. On the Routes tab, select Add route > Published application.

  3. Enter a hostname for the application (for example, httpbin.<your-domain>.com).

  4. Under Service, enter http://httpbin-service. httpbin-service is the name of the Kubernetes service defined in httpbinsvc.yaml.

  5. Select Add route.

8. Test the connection

To test, open a new browser tab and go to httpbin.<your-domain>.com. You should see the httpbin homepage.

You can optionally add Cloudflare Access to control who can access the service.