EKS Rolling Update

EKS Rolling Update is a utility for updating the launch configuration of worker nodes in an EKS cluster.

• Intro
• Requirements
• Installation
• Usage
• Configuration
• Contributing
• License

Intro

EKS Rolling Update is a utility for updating the launch configuration of worker nodes in an EKS cluster. It updates worker nodes in a rolling fashion and performs health checks of your EKS cluster to ensure no disruption to service. To achieve this, it performs the following actions:

• Pauses Kubernetes Autoscaler (Optional)
• Finds a list of worker nodes per ASG that do not have a launch config that matches the ASG
• Scales up the desired capacity on the ASG
• Ensures the ASG are healthy and that the new nodes have joined the EKS cluster
• Suspends AWS Autoscaling actions while update is in progress
• Drains outdated EKS outdated worker nodes one by one
• Terminates EC2 instances of the worker nodes one by one
• Detaches EC2 instances from the ASG one by one
• Resumes AWS Autoscaling actions
• Resumes Kubernetes Autoscaler (Optional)

Requirements

• kubectl installed
• KUBECONFIG environment variable set
• AWS credentials configured

EKS Rolling Update expects that you have valid KUBECONFIG and AWS credentials set prior to running.

Installation

Install

virtualenv -p python3 venv
source venv/bin/activate
pip3 install -r requirements.txt

Set KUBECONFIG and context

export KUBECONFIG=~/.kube/config
ktx <environment>

Usage

usage: eks_rolling_update.py [-h] --cluster_name CLUSTER_NAME [--plan [PLAN]]

Rolling update on cluster

optional arguments:
  -h, --help            show this help message and exit
  --cluster_name CLUSTER_NAME, -c CLUSTER_NAME
                        the cluster name to perform rolling update on
  --plan [PLAN], -p [PLAN]
                        perform a dry run to see which instances are out of
                        date

Example:

eks-rolling-update.py -c my-eks-cluster

Configuration

Parameter	Description	Default
K8S_AUTOSCALER_ENABLED	If True Kubernetes Autoscaler will be paused before running update	True
K8S_AUTOSCALER_NAMESPACE	Namespace where Kubernetes Autoscaler is deployed	""
K8S_AUTOSCALER_DEPLOYMENT	Deployment name of Kubernetes Autoscaler	""
ASG_DESIRED_STATE_TAG	Temporary tag which will be saved to the ASG to store the state of the EKS cluster prior to update	eks-rolling-update:desired_capacity
ASG_ORIG_CAPACITY_TAG	Temporary tag which will be saved to the ASG to store the state of the EKS cluster prior to update	eks-rolling-update:original_capacity
CLUSTER_HEALTH_WAIT	Number of seconds to wait after ASG has been scaled up before checking health of the cluster	90
GLOBAL_MAX_RETRY	Number of attempts of a health check	12
GLOBAL_HEALTH_WAIT	Number of seconds to wait before retrying a health check	20
DRY_RUN	If True, only a query will be run to determine which worker nodes are outdated without running an update operation	False

Contributing

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.

License

This project is licensed under the Apache 2.0 License - see the LICENSE file for details