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:

	#!/bin/bash

	########

	# Purpose :- To Restore backup of MongoDB Collections from AWS s3
	# Requirement :- Make Sure you took backup via backupMongo_bucket.sh
	# Bug Report to :- jadhav.nitin941@gmail.com
	########

	PROGNAME=$(basename $0)

	[ec2-user ~]$ lsblk
	NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
	xvdf 202:80 0 100G 0 disk
	xvda1 202:1 0 8G 0 disk /
	The output of lsblk removes the /dev/ prefix from full device paths. In this example, /dev/xvda1 is mounted as the root device (note the MOUNTPOINT is listed as /, the root of the Linux file system hierarchy), and /dev/xvdf is attached, but it has not been mounted yet.

	Determine whether you need to create a file system on the volume. New volumes are raw block devices, and you need to create a file system on them before you can mount and use them. Volumes that have been restored from snapshots likely have a file system on them already; if you create a new file system on top of an existing file system, the operation overwrites your data. Use the sudo file -s device command to list special information, such as file system type.

	[ec2-user ~]$ sudo file -s /dev/xvdf
	/dev/xvdf: data

	Ansible playbook to setup HTTPS using Let's encrypt on nginx.

	The Ansible playbook installs everything needed to serve static files from a nginx server over HTTPS.
	The server pass A rating on [SSL Labs](https://www.ssllabs.com/).

	To use:
	1. Install [Ansible](https://www.ansible.com/)
	2. Setup an Ubuntu 16.04 server accessible over ssh
	3. Create `/etc/ansible/hosts` according to template below and change example.com to your domain
	4. Copy the rest of the files to an empty directory (`playbook.yml` in the root of that folder and the rest in the `templates` subfolder)

	# Клонируем исходный репозиторий без рабочего каталога (--bare)
	git clone --bare https://github.com/exampleuser/old-repository.git


	cd old-repository.git
	# Делаем mirror-push(будут скопированы все ветки и тэги) в новый репозиторий
	git push --mirror https://github.com/exampleuser/new-repository.git

	cd ..
	# Удаляем папку с репозиторием

	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: ""

	.DEFAULT_GOAL:=help
	THIS_FILE := $(lastword $(MAKEFILE_LIST))
	CRED_TMP := /tmp/.credentials.tmp
	CRED := ~/.aws/credentials

	PARENT:=iamA
	SERIAL:=arn:aws:iam::1234567890ab:mfa/iam-username
	DURATION:=

	code:=000000