Cluster upgrades

An eksctl-managed cluster can be upgraded in 3 easy steps:

1. upgrade control plane version with eksctl upgrade cluster
2. update default add-ons:
   • kube-proxy
   • aws-node
   • coredns
3. replace each of the nodegroups by creating a new one and deleting the old one

Please make sure to read this section in full before you proceed.

Info

Kubernetes supports version drift of up-to two minor versions during upgrade process. So nodes can be up to two minor versions ahead or behind the control plane version. You can only upgrade the control plane one minor version at a time, but nodes can be upgraded more than one minor version at a time, provided the nodes stay within two minor versions of the control plane.

Info

The old eksctl update cluster will be deprecated. Use eksctl upgrade cluster instead.

Updating control plane version

Control plane version upgrades must be done for one minor version at a time.

To upgrade control plane to the next available version run:

eksctl upgrade cluster --name=<clusterName>

This command will not apply any changes right away, you will need to re-run it with --approve to apply the changes.

The target version for the cluster upgrade can be specified both with the CLI flag:

eksctl upgrade cluster --name<clusterName> --version=1.16

or with the config file

cat cluster1.yaml
---
apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig

metadata:
  name: cluster-1
  region: eu-north-1
  version: "1.16"

eksctl upgrade cluster --config-file cluster1.yaml

Warning

The only values allowed for the --version and metadata.version arguments are the current version of the cluster or one version higher. Upgrades of more than one Kubernetes version are not supported at the moment.

Upgrading nodegroups

You should upgrading nodegroups only after you ran eksctl upgrade cluster.

If you have a simple cluster with just an initial nodegroup (i.e. created with eksctl create cluster), the process is very simple.

Get the name of old nodegroup:

eksctl get nodegroups --cluster=<clusterName>

Note

You should see only one nodegroup here, if you see more - read the next section.

Create new nodegroup:

eksctl create nodegroup --cluster=<clusterName>

Delete old nodegroup:

eksctl delete nodegroup --cluster=<clusterName> --name=<oldNodeGroupName>

Note

This will drain all pods from that nodegroup before the instances are deleted.

Updating multiple nodegroups

If you have multiple nodegroups, it's your responsibility to track how each one was configured. You can do this by using config files, but if you haven't used it already, you will need to inspect your cluster to find out how each nodegroup was configured.

In general terms, you are looking to:

• review nodegroups you have and which ones can be deleted or must be replaced for the new version
• note down configuration of each nodegroup, consider using config file to ease upgrades next time

To create a new nodegroup:

eksctl create nodegroup --cluster=<clusterName> --name=<newNodeGroupName>

To delete old nodegroup:

eksctl delete nodegroup --cluster=<clusterName> --name=<oldNodeGroupName>

Updating multiple nodegroups with config file

If you are using config file, you will need to do the following.

Edit config file to add new nodegroups, and remove old nodegroups. If you just want to upgrade nodegroups and keep the same configuration, you can just change nodegroup names, e.g. append -v2 to the name.

To create all of new nodegroups defined in the config file, run:

eksctl create nodegroup --config-file=<path>

Once you have new nodegroups in place, you can delete old ones:

eksctl delete nodegroup --config-file=<path> --only-missing

Note

First run is in plan mode, if you are happy with the proposed changes, re-run with --approve.

Updating default add-ons

There are 3 default add-ons that get included in each EKS cluster, the process for updating each of them is different, hence there are 3 distinct commands that you will need to run.

Info

All of the following commands accept --config-file.

Note

By default each of these commands runs in plan mode, if you are happy with the proposed changes, re-run with --approve.

To update kube-proxy, run:

eksctl utils update-kube-proxy --cluster=<clusterName>

To update aws-node, run:

eksctl utils update-aws-node --cluster=<clusterName>

To update coredns, run:

eksctl utils update-coredns --cluster=<clusterName>

Once upgraded, be sure to run kubectl get pods -n kube-system and check if all addon pods are in ready state, you should see something like this:

NAME                       READY   STATUS    RESTARTS   AGE
aws-node-g5ghn             1/1     Running   0          2m
aws-node-zfc9s             1/1     Running   0          2m
coredns-7bcbfc4774-g6gg8   1/1     Running   0          1m
coredns-7bcbfc4774-hftng   1/1     Running   0          1m
kube-proxy-djkp7           1/1     Running   0          3m
kube-proxy-mpdsp           1/1     Running   0          3m