Skip to content

Upgrade Considerations#

Upgrading from MKE 3 to MKE 4 requires careful preparation to avoid data loss and ensure a successful migration. The following considerations cover essential backup requirements and critical compatibility constraints for air-gapped environments.

Backup your MKE 3 cluster#

Before you upgrade to MKE 4, confirm the existence of a backup of your MKE 3 cluster and review the Back up MKE disaster recovery documentation for MKE 3.

Info

The Swarm cluster and all associated artifacts are not included in the upgrade from MKE 3 to MKE 4.

Back up all non-MKE components separately, making sure to check both manager and worker nodes, as these are at risk of being deleted rather than migrated during the upgrade to MKE 4.

Roll back your custom ingress-nginx controller#

If you previously disabled the MKE 3 built-in ingress-nginx controller and replaced it with a Helm-based patched ingress controller, as detailed in How to Mitigate Risk for NGINX Ingress Controller Vulnerabilities Affecting Mirantis Kubernetes Engine, you must revert those changes before upgrading to MKE 4. Refer to Upgrade Nginx ingress controller for detailed instructions.

If you installed a custom ingress-nginx controller using Helm, contact Mirantis Support for rollback guidance.

Air-gapped environment upgrades#

To upgrade MKE 3 to MKE 4 in an air-gapped environment, you must first download and install MKE 4 OCI binaries to a container registry inside the air gap. Ensure that the following requirements are met before you start the upgrade:

  • The registry inside the air gap must be an OCI-compliant hierarchical registry. For this, Mirantis recommends Mirantis Secure Registry 4, which is based on a recent release of Harbor Registry.

  • The container image management utility you use to push MKE 4 binaries to the registry must be OCI-compatible. For this, Mirantis recommends skopeo, version 1.17.0 or later.

Specific to Windows worker nodes

If your cluster has Windows worker nodes, the air gap registry must also hold the Windows MKE 4 images that these nodes require. Ensure that the Windows image set is mirrored alongside the Linux images before you begin the upgrade as mkectl will fail the upgrade for clusters with windows nodes if Windows images are not present in the registry at the time of upgrade.

Refer to Offline installation for instructions on how to install MKE 4 in an air-gapped environment.