Upgrading Azure Arc enabled Kubernetes agents

Azure Arc enabled Kubernetes provides auto-upgrade and manual-upgrade capabilities for its agents. If use disable auto-upgrade and instead rely on manual-upgrade, version support policy is applicable for Arc agents and the underlying Kubernetes cluster.

Toggle auto-upgrade on or off when connecting cluster to Azure Arc

Azure Arc enabled Kubernetes provides its agents with out- of-the-box auto-upgrade capabilities.

The following command connects a cluster to Azure Arc with auto-upgrade enabled:

az connectedk8s connect --name AzureArcTest1 --resource-group AzureArcTest

With auto-upgrade enabled, the agent polls Azure hourly for availability of a newer version of agents. If the agent finds an available newer version, it triggers a Helm chart upgrade for the Azure Arc agents.

To opt-out of auto-upgrade, specify the --disable-auto-upgrade parameter while connecting the cluster to Azure Arc. The following command connects a cluster to Azure Arc with auto-upgrade disabled:

az connectedk8s connect --name AzureArcTest1 --resource-group AzureArcTest --disable-auto-upgrade

Tip

If you plan to disable auto-upgrade, please refer to the version support policy for Azure Arc enabled Kubernetes.

Toggle auto-upgrade on/off after connecting cluster to Azure Arc

After you connect a cluster to Azure Arc, you can toggle the auto-upgrade capability with the az connectedk8s update command, as shown below:

az connectedk8s update --name AzureArcTest1 --resource-group AzureArcTest --auto-upgrade false

Manually upgrade agents

If you have disabled auto-upgrade for agents, you can manually initiate upgrades for these agents using the az connectedk8s upgrade command as shown below:

az connectedk8s upgrade -g AzureArcTest1 -n AzureArcTest --agent-version 1.1.0

Azure Arc enabled Kubernetes follows the standard semantic versioning scheme of MAJOR.MINOR.PATCH for versioning its agents.

Each number in the version indicates general compatibility with the previous version:

  • Major versions change when there are incompatible API updates or backwards-compatibility may be broken.
  • Minor versions change when functionality changes are backwards-compatible to other minor releases.
  • Patch versions change when backwards-compatible bug fixes are made.

Version support policy

When you create support issues, Azure Arc enabled Kubernetes practices the following version support policy:

  • Azure Arc enabled Kubernetes agents have a support window of "N-2" where 'N' is the latest minor release of agents.

    • For example, if Azure Arc enabled Kubernetes introduces 0.28.a today, versions 0.28.a, 0.28.b, 0.27.c, 0.27.d, 0.26.e, and 0.26.f are supported by Azure Arc.
  • Kubernetes clusters connecting to Azure Arc have a support window of "N-2", where 'N' is the latest stable minor release of upstream Kubernetes.

    • For example, if Kubernetes introduces 1.20.a today, versions 1.20.a, 1.20.b, 1.19.c, 1.19.d, 1.18.e, and 1.18.f are supported.

How often are minor version releases of Azure Arc enabled Kubernetes available?

One minor version of Azure Arc enabled Kubernetes agents is released approximately once a month.

What happens if I'm using an agent version or a Kubernetes version outside the official support window?

'Outside of Support' means that the versions you're running are outside the "N-2" supported versions of agents and upstream Kubernetes clusters. To proceed with the support issue, you'll be asked to upgrade the cluster and the agents to a supported version.

Next steps