Vitaly Lobachev vlobachev

Upgrading Kubernetes Cluster with Kops, and Things to Watch Out For

Alright! I'd like to apologize for the inactivity for over a year. Very embarrassingly, I totally dropped the good habit. Anyways, today I'd like to share a not so advanced and much shorter walkthrough on how to upgrade Kubernetes with kops.

At Buffer, we host our own k8s (Kubernetes for short) cluster on AWS EC2 instances since we started our journey before AWS EKS. To do this effectively, we use kops. It's an amazing tool that manages pretty much all aspects of cluster management from creation, upgrade, updates and deletions. It never failed us.

How to start?

Okay, upgrading a cluster always makes people nervous, especially a production cluster. Trust me, I've been there! There is a saying, hope is not a strategy. So instead of hoping things will go smoothly, I always have bias that shit will hit the fan if you skip testing. Plus, good luck explaining to people

3 Virtual Machines Kubernetes cluster

Dependencies

You should install VirtualBox and Vagrant before you start.

Creating the cluster

You should create a Vagrantfile in an empty directory with the following content:

specify the region

export AWS_DEFAULT_REGION=ap-northeast-1
aws logs describe-log-groups --query 'logGroups[*].logGroupName' --output table | \
awk '{print $2}' | grep -v ^$ | while read x; do  echo "deleting $x" ; aws logs delete-log-group --log-group-name $x; done

only delete loggroup name starting with /aws/lambda

	# Login to AWS registry (must have docker running)
	docker/login:
	$$(aws ecr get-login --no-include-email --region us-east-1 --profile=mycompany)

	# Build docker target
	docker/build:
	docker build -f Dockerfile --no-cache -t mycompany/myapp .

	# Tag docker image
	docker/tag:

	version: '2'
	services:
	openldap:
	image: osixia/openldap:1.2.3
	container_name: openldap
	environment:
	LDAP_LOG_LEVEL: "256"
	LDAP_ORGANISATION: "Example Inc."
	LDAP_DOMAIN: "example.org"
	LDAP_BASE_DN: ""