10-cluster-upgrading.md

Upgrade an Azure Kubernetes Service (AKS) cluster

Azure Container Service (AKS) makes it easy to perform common management tasks including upgrading Kubernetes clusters.

Upgrade an AKS cluster

Before upgrading a cluster, use the az aks get-upgrades command to check which Kubernetes releases are available for upgrade.

NOTE: This operation could take ~1 hour

az aks get-upgrades --name $CLUSTER_NAME --resource-group $NAME --output table

Output:

Name     ResourceGroup    MasterVersion    NodePoolVersion       Upgrades
-------  ---------------  ---------------  -------------------  -------------------
default  myResourceGroup  1.11.2           1.11.2               1.11.3

In this case, we have one version available for upgrade: 1.11.2. We can use the az aks upgrade command to upgrade to the latest available version. During the upgrade process, nodes are carefully [cordoned and drained][kubernetes-drain] to minimize disruption to running applications. Before initiating a cluster upgrade, ensure that you have enough additional compute capacity to handle your workload as cluster nodes are added and removed.

az aks upgrade --name $CLUSTER_NAME --resource-group $NAME --kubernetes-version 1.11.3

Output:

{
  "id": "/subscriptions/4f48eeae-9347-40c5-897b-46af1b8811ec/resourcegroups/myResourceGroup/providers/Microsoft.ContainerService/managedClusters/myK8sCluster",
  "location": "eastus",
  "name": "myK8sCluster",
  "properties": {
    "accessProfiles": {
      "clusterAdmin": {
        "kubeConfig": "..."
      },
      "clusterUser": {
        "kubeConfig": "..."
      }
    },
    "agentPoolProfiles": [
      {
        "count": 1,
        "dnsPrefix": null,
        "fqdn": null,
        "name": "myK8sCluster",
        "osDiskSizeGb": null,
        "osType": "Linux",
        "ports": null,
        "storageProfile": "ManagedDisks",
        "vmSize": "Standard_D2_v2",
        "vnetSubnetId": null
      }
    ],
    "dnsPrefix": "myK8sClust-myResourceGroup-4f48ee",
    "fqdn": "myk8sclust-myresourcegroup-4f48ee-406cc140.hcp.eastus.azmk8s.io",
    "kubernetesVersion": "1.11.3",
    "linuxProfile": {
      "adminUsername": "azureuser",
      "ssh": {
        "publicKeys": [
          {
            "keyData": "..."
          }
        ]
      }
    },
    "provisioningState": "Succeeded",
    "servicePrincipalProfile": {
      "clientId": "e70c1c1c-0ca4-4e0a-be5e-aea5225af017",
      "keyVaultSecretRef": null,
      "secret": null
    }
  },
  "resourceGroup": "myResourceGroup",
  "tags": null,
  "type": "Microsoft.ContainerService/ManagedClusters"
}

You can now confirm the upgrade was successful with the az aks show command.

az aks show --name $CLUSTER_NAME --resource-group $NAME --output table

Output:

Name          Location    ResourceGroup    KubernetesVersion    ProvisioningState    Fqdn
------------  ----------  ---------------  -------------------  -------------------  ----------------------------------------------------------------
myK8sCluster  eastus     myResourceGroup  1.11.3                Succeeded            myk8sclust-myresourcegroup-3762d8-2f6ca801.hcp.eastus.azmk8s.io

Attribution:

Content originally created by @gabrtv et al. from this Azure Doc