Simple bash script to change AMI in AWS EKS cluster

Sometime you need some not standart AMI in kubernetes cluster, for example you want to preload some docker images in kubernetes node

Fork https://github.com/awslabs/amazon-eks-ami
Make some changes in https://github.com/awslabs/amazon-eks-ami/blob/v20210208/scripts/install-worker.sh - for example

sudo systemctl start docker

# this will preload and extract mysql image on kubernetes node
# as the result, when node start - it's will speed up pod start in cluster ~ 40s
sudo docker pull mysql:8.0.23

Update AMI (with cached docker layers) in EKS cluster, without recreating ASG

#!/bin/sh

version=^eksctl-
ami=<SOME-AMI>

echo "WARNING!! this will create new launch-template-version in eks cluster"
sleep 30s

set -ex

aws autoscaling describe-auto-scaling-groups --max-items 100 | jq -r '.AutoScalingGroups[] | "\(.AutoScalingGroupName) \(.MixedInstancesPolicy.LaunchTemplate.LaunchTemplateSpecification.LaunchTemplateName)"' | grep -i $version | while read line
do
  AutoScalingGroupName=`echo $line | awk '{print $1}'`
  LaunchTemplateName=`echo $line | awk '{print $2}'`
  template=`aws ec2 create-launch-template-version --launch-template-name "$LaunchTemplateName" --source-version 1 --launch-template-data "{\"ImageId\":\"$ami\"}"`
  VersionNumber=`echo $template | jq -r '.LaunchTemplateVersion.VersionNumber'`
  aws autoscaling update-auto-scaling-group \
  --auto-scaling-group-name $AutoScalingGroupName \
  --mixed-instances-policy "{\"LaunchTemplate\":{\"LaunchTemplateSpecification\":{\"LaunchTemplateName\":\"$LaunchTemplateName\",\"Version\":\"$VersionNumber\"}}}"
done

maksim-paskal/change-ami-to-aws-eks.md

Simple bash script to change AMI in AWS EKS cluster