There are two things you need to do to upgrade Kubernetes in EKS.

Unlike Azure AKS where you can upgrade with a single button, in AWS EKS you need to upgrade the cluster and worker nodes separately.

Upgrade Cluster

=> Login into AWS console.

=> Go to EKS services.

=> Click on Clusters

Upgrade Worker Nodes

Reference Link: https://docs.aws.amazon.com/eks/latest/userguide/update-stack.html

Step 1:

Go to Worker node cloud formation stack and click on Update

Step 2:

Click on “Replace current template”

Paste the following URL: https://amazon-eks.s3-us-west-2.amazonaws.com/cloudformation/2019-09-17/amazon-eks-nodegroup.yaml

Click “Next”

Step 3:

Update the following parameters

1

NodeAutoScalingGroupDesiredCapacity = NodeAutoScalingGroupDesiredCapacity

1
2

NodeAutoScalingGroupMaxSize = NodeAutoScalingGroupDesiredCapacity + 1 (or more)
(It must be more than what you have)

1
2
3

NodeImageIdSSMParam = /aws/service/eks/optimized-ami/`1.14`/amazon-linux-2/recommended/image_id
(If your cluster version is 1.13 change it to 1.13. Ideally it should match with the Cluster version. Otherwise the upgrade won't work.
You will end up in `matchnodeselector` error and `NotReady` status)

Leave the other fields to default

Click “Next”

Step 4:

Go to last page and check the box. Click “Update”

Once the stack is updated, Connect to your cluster. You should see your version upgraded to 1.14

kubectl get nodes