How To Install Docker and Minikube for Kubernetes on Ubuntu 20.04

Minikube is a defacto for testing Kubernetes on the local computer. It has all the basic features from Kubernetes, and it’s raw, no plugin or customized feature added. So if it’s working on Minikube, it should run on managed Kubernetes engines like Google Kubernetes Engine, Amazon Elastic Kubernetes Service (EKS), Azure Kubernetes Service (AKS) etc with minimal config changes.

Alternative for Minikube are k3s, microk8s, k0s.

Minimum Requirement System

Minimum requirement system for Minikube
4 GB memory
2 CPU
10 GB Disk (SSD Prefered)
it’s the minimum, so your computer should have more memory because we run another application other than Minikube itself. My computer had 32 Memory, so I have plenty memory left for Minikube.

Initial Setup

This initial setup will help to speed up the installation process because we install the dependency first. It should not throw any dependency error later on.

sudo apt-get install ca-certificates curl gnupg lsb-release wget

Install Cloud Tools

These cloud tools are basically what we need to manage the Kubernetes cluster. Depending on your need, you may need to install more tools, but for a basic or beginner, it should be enough as a starting point.

1. kubectl

curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
sudo install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl

2. helm

wget https://get.helm.sh/helm-v3.8.0-linux-amd64.tar.gz
tar zxvf helm-v3.8.0-linux-amd64.tar.gz
sudo install -o root -g root -m 0755 linux-amd64/helm /usr/local/bin/helm

Verify the tools working by running command

kubectl version
helm version

verify cloud tools

Install Docker

For the docker itself, use the docker from official docker repository, it’ll always updated when new release coming. So for development it’s really important to test on the latest version.

Install the latest version of docker from docker apt repository

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
echo   "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt update
sudo apt install docker-ce docker-ce-cli containerd.io

Verify installed version

docker --version
# output
Docker version 20.10.12, build e91ed57

To able run the docker by a normal user, add docker group to your current user

sudo usermod -aG docker $USER
# verify 
id $USER

usermod docker

after adding a new group we need to log out and log in again. My preferred method is just to reboot

sudo reboot

Install Minikube

curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
sudo install -o root -g root -m 0755  minikube-linux-amd64 /usr/local/bin/minikube

By default, minikube use 2 GB memory and 2 CPU, but for testing a lot of software or feature that won’t be enough, depend on your computer memory you can use 50% of available memory or more. We can customize this by running

minikube start --memory 4096 --cpus 2

it’ll use the latest version of Kubernetes, to use a specific version add --kubernetes-version=VERSION at the end of the command

# example
minikube start --memory 4096 --cpus 2 --kubernetes-version=v1.20.1

minikube start

Check the kubernetes using kubectl

kubectl get ns
# output
NAME              STATUS   AGE
default           Active   5m4s
kube-node-lease   Active   5m6s
kube-public       Active   5m6s
kube-system       Active   5m6s

Pull from docker registry and run busybox pod on your cluster

kubectl run busybox --image=busybox --command sleep infinity

that pod will run forever, because we add sleep infinity. It’ll helpful for debugging

Minikube with local Docker Images

Create a simple docker image, using nginx as a base image. Everytime use run/visit the docker image, it’ll return ‘Atetux local docker’. Create new folder for our little project

mkdir -p ~/docker/nginx-custom
cd ~/docker/nginx-custom

create new file for index.html

echo 'Atetux local docker' > index.html

create new file Dockerfile

FROM nginx
COPY index.html /usr/share/nginx/html/

the build the docker image

docker build . -t nginx-atetux

build docker image for kubernetes
After the build finish, deploy it to kubernetes

kubectl run nginx-atetux --image=nginx-atetux:latest --image-pull-policy=IfNotPresent

for some reason you won’t be able to download the images

kubectl get pods
# output
nginx-atetux   0/1     ErrImagePull   0               46s

That is because your local docker and minikube docker run on the different daemon.

To able deploying docker from your local docker, run the command below to use minikube docker daemon instead of your docker

eval $(minikube -p minikube docker-env)

build the image again

docker build . -t nginx-atetux

check the pod again, it should be on running condition

kubectl get pods
# output
nginx-atetux   1/1     Running   0              4m21s

to verify this is working, both of these commands should give the same output

minikube image list
docker images

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