kubespray/docs/upgrades.md

Upgrading Kubernetes in Kargo

Description

Kargo handles upgrades the same way it handles initial deployment. That is to say that each component is laid down in a fixed order. You should be able to upgrade from Kargo tag 2.0 up to the current master without difficulty. You can also individually control versions of components by explicitly defining their versions. Here are all version vars for each component:

• docker_version
• kube_version
• etcd_version
• calico_version
• calico_cni_version
• weave_version
• flannel_version
• kubedns_version

Unsafe upgrade example

If you wanted to upgrade just kube_version from v1.4.3 to v1.4.6, you could deploy the following way:

ansible-playbook cluster.yml -i inventory/inventory.cfg -e kube_version=v1.4.3

And then repeat with v1.4.6 as kube_version:

ansible-playbook cluster.yml -i inventory/inventory.cfg -e kube_version=v1.4.6

Graceful upgrade

Kargo also supports cordon, drain and uncordoning of nodes when performing a cluster upgrade. There is a separate playbook used for this purpose. It is important to note that upgrade-cluster.yml can only be used for upgrading an existing cluster. That means there must be at least 1 kube-master already deployed.

git fetch origin
git checkout origin/master
ansible-playbook upgrade-cluster.yml -b -i inventory/inventory.cfg

Upgrade order

As mentioned above, components are upgraded in the order in which they were installed in the Ansible playbook. The order of component installation is as follows:

• Docker
• etcd
• kubelet and kube-proxy
• network_plugin (such as Calico or Weave)
• kube-apiserver, kube-scheduler, and kube-controller-manager
• Add-ons (such as KubeDNS)