How to create a k8s cluster with kubeadm on Azure

1. Build a resource group named ‘testk8s’ and create below resources under the resource group

a. Networking

Virtual Network: testk8s-vnet

Address space: 192.169.0.0/16

Subnet: ‘default’ 192.169.0.0/16

Network Security Group: testk8s-nsg

Routetable: testk8s-routetable

b. VM

Master: testk8s-m1

Availabilty Set: testk8s-m

Vnet: testk8s-vnet

subnet: default

Agent: testk8s-a1

Availability Set: testk8s-a

Vnet: testk8s-vnet

subnet: default

2. Login into the VM ‘testk8s-m1’ and follow below to install the kubeadm/kubectl/kubelet/docker

Installing kubeadm

3. Modify below configuration file per requirement. Below is an example which has Pod CIDR as ‘10.244.0.0/16’

Cloud Providers

apiVersion: kubeadm.k8s.io/v1beta1
kind: InitConfiguration
nodeRegistration:
  kubeletExtraArgs:
  cloud-provider: "azure"
  cloud-config: "/etc/kubernetes/cloud.conf"
---
apiVersion: kubeadm.k8s.io/v1beta1
kind: ClusterConfiguration
kubernetesVersion: v1.13.0
apiServer:
  extraArgs:
  cloud-provider: "azure"
  cloud-config: "/etc/kubernetes/cloud.conf"
  extraVolumes:
  - name: cloud
    hostPath: "/etc/kubernetes/cloud.conf"
    mountPath: "/etc/kubernetes/cloud.conf"
controllerManager:
  extraArgs:
  cloud-provider: "azure"
  cloud-config: "/etc/kubernetes/cloud.conf"
  extraVolumes:
  - name: cloud
 hostPath: "/etc/kubernetes/cloud.conf"
 mountPath: "/etc/kubernetes/cloud.conf"
networking:
 serviceSubnet: "10.240.0.0/16"
 podSubnet: "10.244.0.0/16"

4. Create an AD application

Create identity for Azure app in portal

5. Modify the configuration file ‘/etc/kubernetes/cloud.conf’

{
    "cloud":"AzurePublicCloud",
    "tenantId": "xxx",
    "subscriptionId": "xxx",
    "aadClientId": "xxx",
    "aadClientSecret": "xxx",
    "resourceGroup": "k8s",
    "location": "eastus",
    "vmType": "standard",
    "subnetName": "master",
    "securityGroupName": "testslk8s",
    "vnetName": "k8s-vnet",
    "vnetResourceGroup": "",
    "routeTableName": "testk8s-routetable",
    "primaryAvailabilitySetName": "testk8s",
    "primaryScaleSetName": "",
    "cloudProviderBackoff": true,
    "cloudProviderBackoffRetries": 6,
    "cloudProviderBackoffExponent": 1.5,
    "cloudProviderBackoffDuration": 5,
    "cloudProviderBackoffJitter": 1,
    "cloudProviderRatelimit": true,
    "cloudProviderRateLimitQPS": 3,
    "cloudProviderRateLimitBucket": 10,
    "useManagedIdentityExtension": false,
    "userAssignedIdentityID": "",
    "useInstanceMetadata": true,
    "loadBalancerSku": "Basic",
    "excludeMasterFromStandardLB": false,
    "providerVaultName": "",
    "maximumLoadBalancerRuleCount": 250,
    "providerKeyName": "k8s",
    "providerKeyVersion": ""
}

6. Initialize the cluster

sudo kubeadm init -config kubeadm.conf

Creating a single master cluster with kubeadm

7. Install the network addon

Creating a single master cluster with kubeadm

8. Make sure the master node is ‘ready’ and all kube-system pods are running

kubectl get node,pod -n kube-system

9. login to the VM ‘testk8s-a1’

10. Follow the step2 to install docker/kubeadm/kubelet/kubectl

11. Use the command in the output of step6 to join the cluster or follow below

Creating a single master cluster with kubeadm

12. Execute below to verify. It’s expected to create two pods in the cluster and a loadbalancer and a public IP in Azure platform.

kubectl apply -f https://raw.githubusercontent.com/Azure-Samples/azure-voting-app-redis/master/azure-vote-all-in-one-redis.yaml