Re-run the install script to upgrade Replicated to the latest version.
curl -sSL -o install.sh https://get.replicated.com/kubernetes-init sudo bash ./install.sh
If an upgrade of Kubernetes is required, the script will begin the upgrade and prompt to run upgrade scripts on each node in the cluster. When upgrading only the Replicated version, the install script will be required to be re-run on only the primary. Because not all nodes are upgraded at the same time, application developers can ensure that downtime is minimized or eliminated. This can be achieved by ensuring that multiple replicas of a deployment/statefulset are not scheduled on the same node (via pod anti-affinity rules) and also by setting pod disruption budgets to ensure that the minimum number of replicas required for the application to function are always running. There are networking considerations as well. While a node is being upgraded it will not be able to properly route network connections. This should be handled by load balancers or application level failover.
For a single-node ‘cluster’, downtime when upgrading Kubernetes is unfortunately unavoidable.
Upgrading Airgap Installs
Airgap installations can be upgraded by downloading a newer version of the Replicated release, uncompressing it and re-running the install script using the airgap flag. The latest Replicated release can be found at https://s3.amazonaws.com/replicated-airgap-work/replicated__docker__kubernetes.tar.gz.
tar xzvf replicated__docker__kubernetes.tar.gz cat ./kubernetes-init.sh | sudo bash -s airgap
Installations, with internet access, can be configured to automatically update if there is an update available that does not require a change in the version of Kubernetes. Refer to this compatability table, when configuring your application to auto-upgrade.
Auto-upgrade will automatically upgrade to the latest
replicated_version in the
host_requirements section of your application YAML. This feature will only work in replicated versions greater than 2.23.0.