Minikube introduction

Github link: https://github.com/kubernetes/minikube

Minikube is the single-node version of kubernetes which will help you easily delpoy kubernetes alike cluster in your own personal computer.

You can use kubectl command to do the same thing as you are operating a kubernetes cluster.

Mini kube installation

You can click here for guidence of how to set up minikube.

How to get access to your minikube cluster from internet outside from your LAN

In default, you can only visit your minikube cluster in the machine where you delpoy minikube(use command minikube start) casued by private docker port exposure by minikube docker as you can see from below.

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containerId   kicbase/stable:v0.0.18          "/usr/local/bin/entr…"   23 hours ago   Up 23 hours   127.0.0.1:49202->22/tcp, 127.0.0.1:49201->2376/tcp, 127.0.0.1:49200->5000/tcp, 127.0.0.1:49203->8443/tcp, 127.0.0.1:49198->8443/tcp, 127.0.0.1:49199->32443/tcp   minikube

All ports are only visited by local network 127.0.0.1.

So you have to tell minikube to expose these ports as you wish.

You can use minikube start --help for more information to check how to expose these ports. You can find more details from this Pull Request.

Step 1

Use the command below:

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minikube start --ports=10000(you can change the port as you want):8443 --apiserver-names=${your_fixed_ip_address_or_your_domain_address} --base-image="kicbase/stable:v0.0.18" --mount=false --mount-string="/usr/local/minikube-files:/host-mount-files"

--ports: tell minikube which port you want to map to machine port.

--apiserver-name: provide this information to let minikube add this into its credential file.

--base-image: in default, minikube will pull the image from gcr.io. If you can’t visit gcr.io, use this argument topull image from docker.io.

--mount=true --mount-string="/usr/local/minikube-files:/host-mount-files": Mount host path into minikube docker(but i did not see the related mount option in docker inspect), then you can use volumnMount(hostpath option) to get access to your file in your local machine folder /usr/local/minikube-files.

Step 2

To get the kube config file in minikube cluster.

Minikube usually merge all the config files in to onefile ~/.kube/config and use context to differ from diffrent minikube cluster. My method only works for only having one cluster.

Copy the config file to your personal computer and merge it with ~/.kube/config.Check using kubecm for merging configs.

Step 3

Copy three credential files in minikube located machine to your personal computer.

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scp username@192.168.1.2:~/.minikube/ca.crt ~/.kube/minikube
scp username@192.168.1.2:~/.minikube/profiles/minikube/client.crt ~/.kube/minikube
scp username@192.168.1.2:~/.minikube/profiles/minikube/client.key ~/.kube/minikube

Step 4

Modify the copyed kube config file.

1. Modify clusters[0]/cluster/server(yaml structure path). Replace the hostname part with the value you used in Step 1 in --apiserver-names argument.
2. Modify clusters[0]/cluster/certificate-authority(yaml structure path). Replace the value with the credential path you used in Step 3 -> ~/.kube/minikube/ca.crt.
3. Modify users[0]/user/client-certificate(yaml structure path). Replace the value with the credential path you used in Step 3 -> ~/.kube/minikube/client.crt.
4. Modify users[0]/user/client-key(yaml structure path). Replace the value with the credential path you used in Step 3 -> ~/.kube/minikube/client.key.

Step 5

Use kubectl to visit your minikube clster

Minikube start scripts

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#!/bin/bash

echo 'input password'

sudo ls /

minikube start --nodes=3 --cpus=4 --memory=4g  --apiserver-names=minikube.datavocals.com --base-image="kicbase/stable:v0.0.18" --mount=true --mount-string="/minikube-files:/minikube-files"

echo 'image load'

minikube image load datavocals/hive-2.3.8:alpha
minikube image load datavocals/hadoop-2.7.7:alpha
minikube image load datavocals/spark-2.4.7-hadoop-2.7-scala-2.11:alpha
minikube image load mysql:5.6.50
minikube image load datavocals/metrics-server-amd64:v0.2.1

echo 'enable metrics server'

minikube addons enable metrics-server

sleep 20

kubectl set image deployment/metrics-server metrics-server=datavocals/metrics-server-amd64:v0.2.1 -n kube-system

DOCKER_ID=$(docker ps -n 100 | grep minikube | awk '{print $1}' | tail -n 1)
DOCKER_DIR=$(sudo ls /var/lib/docker/containers | grep $DOCKER_ID)

echo 'stop docker'

sudo systemctl stop docker

sudo sed -i 's#"8443/tcp":\[{"HostIp":"127.0.0.1","HostPort":""}\]}#"8443/tcp":\[{"HostIp":"0.0.0.0","HostPort":"1801"}\]}#g' /var/lib/docker/containers/$DOCKER_DIR/hostconfig.json

sudo systemctl start docker

sudo minikube start