Upgrading Clusters

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This topic describes how to upgrade Kubernetes clusters provisioned by VMware Enterprise PKS (Enterprise PKS) through the Enterprise PKS Command Line Interface (PKS CLI).

For information about how to upgrade PKS-provisioned clusters through the Enterprise PKS tile,
see Verify Errand Configuration in one of the following topics:

• Upgrading Enterprise PKS (Flannel Networking)
• Upgrading Enterprise PKS (NSX-T Networking)

For conceptual information about Enterprise PKS upgrades, see About Enterprise PKS Upgrades.

Overview

Upgrading a PKS-provisioned Kubernetes cluster updates the Enterprise PKS version and the Kubernetes version of the cluster. PKS-provisioned Kubernetes clusters upgrade when:

• You upgrade Enterprise PKS with the Upgrade all clusters errand enabled in the Enterprise PKS tile > Errands.
• You run pks upgrade-cluster or pks upgrade-clusters as described in Upgrade Clusters below.

For example, running pks upgrade-cluster upgrades the cluster you specify to your current version of Enterprise PKS and to the version of Kubernetes that is included with your current version of Enterprise PKS.

WARNING: Do not change the number of master/etcd nodes for any plan that was used to create currently-running clusters. Enterprise PKS does not support changing the number of master/etcd nodes for plans with existing clusters.

Prerequisites

Before upgrading PKS-provisioned Kubernetes clusters:

1. Verify the cluster you are upgrading supports upgrading. For information, see Verify Your Clusters Support Upgrading in the Upgrade Preparation Checklist for Enterprise PKS.
2. Verify that your Kubernetes environment is healthy. For information, see Verifying Deployment Health.
3. Install the PKS CLI. For information, see Installing the PKS CLI.
4. Log in to Enterprise PKS using pks login. For more information, see Logging in to Enterprise PKS.
   

Upgrade Clusters

You can upgrade individual or multiple clusters using the following procedures:

• Upgrade a Single Kubernetes Cluster
  
• Upgrade Multiple Kubernetes Clusters

To monitor or stop a cluster upgrade, follow the procedures in Manage Your Kubernetes Cluster Upgrade Job below.

Upgrade a Single Cluster

The Enterprise PKS CLI provides upgrade-cluster for upgrading an individual Enterprise PKS-provisioned Kubernetes cluster.

To upgrade an individual Kubernetes cluster, run the following command:

pks upgrade-cluster CLUSTER-NAME

Where CLUSTER-NAME is the name of the Kubernetes cluster you want to upgrade.

To upgrade multiple clusters, see Upgrade Multiple Kubernetes Clusters below.

For more information about the pks upgrade-cluster command, see pks upgrade-cluster in the PKS CLI documentation.

Upgrade Multiple Clusters

The Enterprise PKS CLI provides upgrade-clusters for upgrading multiple Enterprise PKS-provisioned Kubernetes clusters. You can upgrade clusters serially, serially with some clusters designated as canary clusters, or entirely in parallel.

To upgrade a single cluster, see Upgrade a Single Kubernetes Cluster above.

For more information about the pks upgrade-clusters command, see pks upgrade-clusters in the PKS CLI documentation.

Upgrade Clusters in Parallel

To upgrade multiple Kubernetes clusters, run the following command:

pks upgrade-clusters --clusters CLUSTER-NAMES --max-in-flight CLUSTER-COUNT --wait

Where:

• CLUSTER-NAMES is a comma-delimited list of the names of the Kubernetes clusters you want to upgrade.

• CLUSTER-COUNT is the maximum number of clusters to upgrade in parallel within an an AZ.

  • If the CLUSTER-NAMES list is longer than the CLUSTER-COUNT, the first set of clusters are upgraded in parallel and subsequent clusters are queued and then upgraded in parallel as the preceding cluster upgrades complete.
    
  • If an upgrade fails for a cluster in the CLUSTER-NAMES list, the job continues to a subsequent cluster in the list.
    
  • To run the cluster upgrade job as a background task, remove the --wait argument.

  Note: Run upgrade-clusters with a --max-in-flight argument less than your BOSH Director > Director Config > Director Workers value. For example, if your Director Workers value remains the default of 5, run upgrade-clusters with a --max-in-flight argument value less than 5.

  Note: max-in-flight is an optional argument. If max-in-flight is not set, Enterprise PKS uses the default max-in-flight value of 1 and the clusters are upgraded serially.

For example:

$ pks upgrade-clusters --clusters k8-cluster-000,k8-cluster-001,k8-cluster-002 --max-in-flight 2  --wait


You are about to upgrade k8-cluster-000, k8-cluster-001 and k8-cluster-002.
Warning: This operation may be long running and may block further operations on the cluster(s) until complete


Continue? (y/n):y
Your taskID for the upgrade task is: d772aba0-2670-4fba-b26c-044b19d6ab60
Started upgrading cluster: k8-cluster-000
Started upgrading cluster: k8-cluster-001
Finished upgrading cluster: k8-cluster-000
Started upgrading cluster: k8-cluster-002
Finished upgrading cluster: k8-cluster-001
Finished upgrading cluster: k8-cluster-002
Upgrade task d772aba0-2670-4fba-b26c-044b19d6ab60 is done.

Upgrade Clusters With Canaries

To upgrade multiple clusters and automatically stop upgrading clusters if a cluster upgrade fails, specify your cluster list as canary clusters. You can specify one or more clusters as canary clusters.

To upgrade multiple clusters with one or more canary clusters, run the following command:

pks upgrade-clusters --canaries CANARY-CLUSTER-NAMES --clusters CLUSTER-NAMES --wait

Where:

• CANARY-CLUSTER-NAMES is a comma-delimited list of the names of the Kubernetes clusters you want to upgrade as canary clusters.

• CLUSTER-NAMES is a comma-delimited list of Kubernetes clusters to upgrade if all canary clusters successfully upgrade.

  • The specified canary clusters are upgraded prior to upgrading the clusters in your CLUSTER-NAMES list.
    
  • Canary clusters are always upgraded serially.
  • If an upgrade fails for a canary cluster, the entire upgrade-clusters job stops.
  • If an upgrade fails for a cluster in the CLUSTER-NAMES list, the upgrade-clusters job continues to a subsequent cluster in the list.
    
  • To run the cluster upgrade job as a background task, remove the --wait argument.
    

  Note: --clusters is a required argument. To configure upgrade-clusters to stop for any cluster upgrade failure, specify only one cluster in your CLUSTER-NAMES list and the remaining clusters in your CANARY-CLUSTER-NAMES list.

  Note: Canary clusters are always upgraded serially. Only the clusters specified in the --clusters list are upgraded in parallel when you run upgrade-clusters with both --canaries and --max-in-flight arguments.

For example:

$ pks upgrade-clusters --canaries k8-cluster-dev,k8-cluster-000,k8-cluster-001  --clusters k8-cluster-002  --wait


You are about to upgrade k8-cluster-dev k8-cluster-000, k8-cluster-001 and k8-cluster-002.
Warning: This operation may be long running and may block further operations on the cluster(s) until complete

Continue? (y/n):y
Your taskID for the upgrade task is: ce31a1bb-380a-453f-afa0-835ffa1ce6ac
Started upgrading cluster: k8-cluster-000
Upgrading cluster succeeded: k8-cluster-000
Started upgrading cluster: k8-cluster-001
Upgrading cluster succeeded: k8-cluster-001
Started upgrading cluster: k8-cluster-dev
Upgrading cluster failed: k8-cluster-dev
Upgrade task ce31a1bb-380a-453f-afa0-835ffa1ce6ac is done.

Manage Your Cluster Upgrade Job

You can use the PKS CLI to monitor and manage your Enterprise PKS-provisioned Kubernetes cluster upgrade jobs.

Monitor Your Clusters

To review the status of the actions being performed on your clusters, run the following command:

pks clusters

For example:

$ pks clusters


Upgrade is available to PKS Version: 1.7.0-build.16


PKS Version     Name               k8s Version  Plan Name  UUID                                  Status       Action
1.7.0-build.16  k8-cluster-000     1.16.7       small      9527ebaa-e2fa-422f-a52b-de3c3f0e39a4  succeeded    UPGRADE
1.7.0-build.16  k8-cluster-001     1.16.7       small      9527ebaa-e2fa-422f-a52b-de3c3f0e39a4  failed       UPGRADE
1.7.0-build.16  k8-cluster-002     1.16.7       small      9527ebaa-e2fa-422f-a52b-de3c3f0e39a4  in progress  UPGRADE
1.7.0-build.16  k8-cluster-003     1.16.7       small      9527ebaa-e2fa-422f-a52b-de3c3f0e39a4  queued       UPGRADE

Monitor Your Cluster Upgrade Job

To review the status of your upgrade-clusters job, run the following command:

pks task TASKID

Where TASKID is the ID of the task that was returned when you ran pks upgrade-clusters.

For example:

$ pks task ce31a1bb-380a-453f-afa0-835ffa1ce6ac


Your upgrade task is: done


Name           Status     Start time                     End time                            isCanary
k8-cluster-000 succeeded  Mon, 14 Oct 2019 12:00:00 PDT  Mon, 14 Oct 2019 12:19:54 PDT       true
k8-cluster-001 failed     Mon, 14 Oct 2019 12:20:00 PDT  ---                                 true

Stop Your Cluster Upgrade Job

To cancel a running upgrade-clusters job, run the following PKS CLI command:

pks cancel-task TASKID

Where TASKID is the ID of the task that was returned when you ran pks upgrade-clusters.

Warning: pks cancel-task does not cancel cluster upgrades currently in progress. This command only cancels a job’s pending cluster upgrades.

After Upgrading Clusters

(Optional) Restore Cluster Sizing

If you scaled your cluster up for the upgrade and you prefer to restore your cluster to its original sizing, you can now scale the cluster back down to its previous configuration. VMware recommends that you not scale down your clusters and continue to run them with recommended configurations, reducing the chance of a future outage.