Kubernetes - Getting Started with the Cloud Controller Manager

• compute
• kubernetes
• Kubernetes-cluster
• kubeadm
• cloud-controller-manager

Cloud Contoller Manager Overview

A Cloud Controller Manager is a daemon that embeds cloud-specific control loops. It can be used to deploy resources in the Scaleway ecosystem.

Currently the scaleway-cloud-controller-manager implements:

• Instances interface: updates nodes with cloud provider specific labels and addresses, also deletes kubernetes nodes when deleted from the cloud-provider.
• LoadBalancer interface: responsible for creating load balancers when a service of type: LoadBalancer is created in Kubernetes.
• Zone interface: makes Kubernetes aware of the failure domain of each node.

The Scaleway Cloud Controller Manager is currently under active development and released as open-source project on GitHub.

Creating a Kubernetes Cluster using kubeadm on Scaleway

The goal of this step is to create a Kubernetes cluster using kubeadm on Scaleway Instances.

To follow this example, you need to create three Ubuntu Bionic Instances:

• master1
• node1
• node2

1. Run the following commands on each of your Instances:

   apt-get update && apt-get install -y \
       iptables \
       arptables \
       ebtables \
       apt-transport-https \
       ca-certificates \
       curl \
       gnupg-agent \
       software-properties-common
   curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
   add-apt-repository \
     "deb [arch=amd64] https://apt.kubernetes.io kubernetes-xenial main"
   curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -
   add-apt-repository \
     "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
     $(lsb_release -cs) \
     stable"
   apt-get update && apt-get install -y \
       docker-ce docker-ce-cli containerd.io kubelet kubeadm kubectl
   apt-mark hold \
       docker-ce docker-ce-cli containerd.io kubelet kubeadm kubectl
   echo KUBELET_EXTRA_ARGS=\"--cloud-provider=external\" > /etc/default/kubelet
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2. Initialize the Kubernetes master on the Instance master1:

   root@master1:~# kubeadm init --control-plane-endpoint=$(scw-metadata PUBLIC_IP_ADDRESS) --apiserver-cert-extra-sans=$(scw-metadata PUBLIC_IP_ADDRESS)
   root@master1:~# mkdir -p ~/.kube
   root@master1:~# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
   root@master1:~# chown $(id -u):$(id -g) $HOME/.kube/config
   root@master1:~# kubectl apply -f https://docs.projectcalico.org/v3.11/manifests/calico.yaml
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3. During the installation the kubeadm join command displays. Note it down as it is required for the worker nodes to join the cluster. You can also copy the kubeconfig file and save it on your local computer.

4. Execute the kubeadm join command on worker node to join the cluster:

   root@node1:~# kubeadm join 10.68.34.145:6443 --token itvo0b.kwoao79ptlj22gno \
       --discovery-token-ca-cert-hash sha256:07bc3f9601f1659771a7a6fd696c2969cbc757b088ec752ba95d5a42c06ed91f
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5. Verify the status of the cluster on the master by running the kubectl get nodes command.

   root@master1:~#  kubectl get nodes
   NAME       STATUS   ROLES    AGE     VERSION
   master1    Ready    master   18m     v1.17.4
   node1      Ready    <none>   8m38s   v1.17.4
   node2      Ready    <none>   2m31s   v1.17.4
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   The cluster is ready and working. Continue by deploying the cloud-controller-manager.

Deploying the cloud-controller-manager on the Cluster

To deploy the cloud-controller-manager the following information are required:

• Your access key.
• Your secret key.
• Your organization id.
• The Scaleway region.

1. Create a k8s-scaleway-secret.yml file containing the following information:

   root@master1:~#  nano k8s-scaleway-secret.yml
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   apiVersion: v1
   kind: Secret
   metadata:
     name: scaleway-secret
     namespace: kube-system
   stringData:
     SCW_ACCESS_KEY: 'xxxxxxxxxxxxxxxx'
     SCW_SECRET_KEY: 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'
     SCW_DEFAULT_REGION: 'fr-par'
     SCW_DEFAULT_ORGANIZATION_ID: 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxx'
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2. Create the secret and deploy the controller

   root@master1:~# kubectl create -f k8s-scaleway-secret.yml
   root@master1:~# kubectl apply -f https://raw.githubusercontent.com/scaleway/scaleway-cloud-controller-manager/master/examples/k8s-scaleway-ccm-latest.yml
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Checking that the cloud-controller-manager is working

1. Verify the cloud-controller-manager is running from the master1 instance:

   root@master1:~# kubectl get pods -n kube-system -l app=scaleway-cloud-controller-manager
   NAME                                                 READY   STATUS    RESTARTS   AGE
   scaleway-cloud-controller-manager-584558b994-rln4j   1/1     Running   0          12s
   root@master1:~# kubectl get nodes
   NAME       STATUS   ROLES    AGE     VERSION
   master1    Ready    master   18m     v1.17.4
   node1      Ready    <none>   8m38s   v1.17.4
   node2      Ready    <none>   2m31s   v1.17.4
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2. Deploy a LoadBalancer service and make sure a public IP is assigned to this service. The service will automatically create a managed Load Balancer on the Scaleway platform.

   Create a lb.yml file that contains the following information:

   root@master1:~# nano lb.yml
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   apiVersion: v1
   kind: Service
   metadata:
     name: example-service
   spec:
     selector:
       app: example
     ports:
       - port: 8765
         targetPort: 9376
     type: LoadBalancer
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3. Create the service from the configuration file:

   root@master1:~# kubectl create -f lb.yml
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4. Verify if the service has been created:

   root@master1:~# kubectl get services
   NAME              TYPE           CLUSTER-IP       EXTERNAL-IP     PORT(S)          AGE
   example-service   LoadBalancer   10.106.144.144   51.159.26.121   8765:30175/TCP   7s
   kubernetes        ClusterIP      10.96.0.1        <none>          443/TCP          21m
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The LoadBalancer service with the internal IP 10.106.144.144 and external IP 51.159.26.121 has been created. You have successfully deployed a cluster with kubeadm and the scaleway-cloud-controlle-manager. For more information about the Scaleway Cloud Controller Manager, follow the project on GitHub.