Kubernetes with Kubespray

Table of contents

• Prerequisite
• Install and configure Kubespray
  • Start Vagrant
  • Configure k8s cluster
  • Run Docker as a non-root user
  • Troubleshooting
• Setting up Helm
• SSH Config
• Using SSHFS to Mount Vagrant on Mac
• Remote Kubernetes Cluster
• K8s Dashboard

 

Prerequisite

• macOS: 10.14 (Mojave)
• Vagrant: 2.2.4
• Ansible: 2.7.9
• Kubespray

 

Install and configure Kubespray

git clone git@github.com:kubernetes-sigs/kubespray.git

cd kubespray

mv inventory/sample/{hosts.ini,hosts.ini.bak}
sed -i -e 's/"download_run_once": "True",/"download_run_once": "False",/' Vagrantfile

 

Start Vagrant

vagrant up

This will spin up 3 VMs and install kubernetes on them. Once they are completed you can connect to any of them by running

$ vagrant ssh k8s-1

 

Configure k8s cluster

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

 

Verify Kubernetes cluster

vagrant@k8s-1:~$ kubectl get nodes -o=wide

NAME    STATUS   ROLES         AGE   VERSION   INTERNAL-IP    EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION      CONTAINER-RUNTIME
k8s-1   Ready    master,node   20h   v1.13.5   172.17.8.101   <none>        Ubuntu 18.04.2 LTS   4.15.0-46-generic   docker://18.6.2
k8s-2   Ready    master,node   20h   v1.13.5   172.17.8.102   <none>        Ubuntu 18.04.2 LTS   4.15.0-46-generic   docker://18.6.2
k8s-3   Ready    node          20h   v1.13.5   172.17.8.103   <none>        Ubuntu 18.04.2 LTS   4.15.0-46-generic   docker://18.6.2

 

Run Docker as a non-root user

Run the following command and then close the current terminal session by running exit command

vagrant@k8s-1:~$ sudo usermod -a -G docker $USER

Now close the current terminal session

vagrant@k8s-1:~$ exit

 

Troubleshooting

If you get an error like the one below,

The connection to the server localhost:8080 was refused - did you specify the right host or port?

Run the following command to solved this issue:

sudo cp /etc/kubernetes/admin.conf $HOME/ && sudo chown $(id -u):$(id -g) $HOME/admin.conf && export KUBECONFIG=$HOME/admin.conf

Now run the command again:

vagrant@k8s-1:~$ kubectl get nodes

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SSH Config

If you want to ssh into your vagrant box without switching into the project directory and typing vagrant ssh k8s-1. Simply copy vagrant ssh-config to your ~/.ssh/config

$ cd ~/Vagrant
$ vagrant ssh-config >> ~/.ssh/config

This will allow you to use ssh k8s-1 from anywhere.

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Using SSHFS to Mount Vagrant on Mac

Copy your public key to your Vagrant box

$ ssh-copy-id vagrant@k8s-1

Create a local directory

$ mkdir ~/Desktop/k8s

Mounting your remote directory

$ sshfs vagrant@k8s-1:/home/vagrant ~/Desktop/k8s

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Remote Kubernetes Cluster

To connect to a remote Kubernetes cluster from you Mac, you'll need copy the Kubernetes credentials to your home directory as shown below.

scp -r vagrant@k8s-1:/home/vagrant/.kube ~/.kube/

That’s all you have to do. Your local Kubectl should be able to connect with the remote Kubernetes cluster now.

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K8s Dashboard

You can access the Kubernetes Dashboard at the following URL
https://first-master:6443/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/#!/login