:warning: [Attempting to upgrade from an older release straight to the latest release is unsupported and likely to break something](https://github.com/kubernetes-sigs/kubespray/issues/3849#issuecomment-451386515) :warning:
See [Multiple Upgrades](#multiple-upgrades) for how to upgrade from older releases to the latest release
:warning: [Do not skip releases when upgrading--upgrade by one tag at a time.](https://github.com/kubernetes-sigs/kubespray/issues/3849#issuecomment-451386515) :warning:
For instance, if you're on v2.6.0, then check out v2.7.0, run the upgrade, check out the next tag, and run the next upgrade, etc.
Assuming you don't explicitly define a kubernetes version in your k8s-cluster.yml, you simply check out the next tag and run the upgrade-cluster.yml playbook
* If you do define kubernetes version in your inventory (e.g. group_vars/k8s-cluster.yml) then either make sure to update it before running upgrade-cluster, or specify the new version you're upgrading to: `ansible-playbook -i inventory/mycluster/hosts.ini -b upgrade-cluster.yml -e kube_version=v1.11.3`
Otherwise, the upgrade will leave your cluster at the same k8s version defined in your inventory vars.
The below example shows taking a cluster that was set up for v2.6.0 up to v2.10.0
```
$ kubectl get node
NAME STATUS ROLES AGE VERSION
apollo Ready master,node 1h v1.10.4
boomer Ready master,node 42m v1.10.4
caprica Ready master,node 42m v1.10.4
$ git describe --tags
v2.6.0
$ git tag
...
v2.6.0
v2.7.0
v2.8.0
v2.8.1
v2.8.2
...
$ git checkout v2.7.0
Previous HEAD position was 8b3ce6e4 bump upgrade tests to v2.5.0 commit (#3087)
HEAD is now at 05dabb7e Fix Bionic networking restart error #3430 (#3431)
# NOTE: May need to sudo pip3 install -r requirements.txt when upgrading.
Previous HEAD position was 05dabb7e Fix Bionic networking restart error #3430 (#3431)
HEAD is now at 9051aa52 Fix ubuntu-contiv test failed (#3808)
```
:info: NOTE: Review changes between the sample inventory and your inventory when upgrading versions. :info:
Some deprecations between versions that mean you can't just upgrade straight from 2.7.0 to 2.8.0 if you started with the sample inventory.
In this case, I set "kubeadm_enabled" to false, knowing that it is deprecated and removed by 2.9.0, to delay converting the cluster to kubeadm as long as I could.
"msg": "DEPRECATION: non-kubeadm deployment is deprecated from v2.9. Will be removed in next release."
...
Are you sure you want to deploy cluster using the deprecated non-kubeadm mode. (output is hidden):
yes
...
$ kubectl get node
NAME STATUS ROLES AGE VERSION
apollo Ready master,node 5h45m v1.12.7
boomer Ready master,node 5h45m v1.12.7
caprica Ready master,node 5h45m v1.12.7
$ git checkout v2.9.0
Previous HEAD position was 6f97687d Release 2.8 robust san handling (#4478)
HEAD is now at a4e65c7c Upgrade to Ansible >2.7.0 (#4471)
```
:warning: IMPORTANT: Some of the variable formats changed in the k8s-cluster.yml between 2.8.5 and 2.9.0 :warning:
If you do not keep your inventory copy up to date, **your upgrade will fail** and your first master will be left non-functional until fixed and re-run.
It is at this point the cluster was upgraded from non-kubeadm to kubeadm as per the deprecation warning.