Installing a Kubernetes cluster and connecting it to Lens
In this tutorial you can experiment with a local Kubernetes cluster that can be installed using VirtualBox or another virtualization product. This time we will use VirtualBox and Vagrant to set it all up.
The Vagrant file will create one Kubernetes master server and two Kubernetes workers. A loadbalancer will also be created and will be used in our next blog about Traefik.
After the installation we use Lens to connect to the created cluster.
You must have a minimum of 16 GB of RAM for setting up this cluster.
Install the boxes
First, we will install the boxes. In your terminal do the following:
vagrant box add ubuntu/bionic64 ==> box: Loading metadata for box 'ubuntu/bionic64' box: URL: https://vagrantcloud.com/ubuntu/bionic64 This box can work with multiple providers! The providers that it can work with are listed below. Please review the list and choose the provider you will be working with. 1) hyperv 2) libvirt 3) virtualbox 4) vmware_desktop # Choose 3) virtualbox
Getting the master, workers and loadbalancer
git clone https://firstname.lastname@example.org/dennisvermeulen/kubernetes-cluster.git cd kubernetes-cluster/k8smaster vagrant up cd ../k8sworker1 vagrant up cd ../k8sworker2 vagrant up cd ../k8slb vagrant up cd ../k8smaster vagrant ssh
vagrant@k8smaster:~$ sudo su - root@k8smaster:~$ kubeadm init --config=kubeadm-config.yaml --upload-certs | tee kubeadm-init.out
Copy config file to communicate with the cluster
root@k8smaster:~$ mkdir -p $HOME/.kube root@k8smaster:~$ sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config root@k8smaster:~$ sudo chown $(id -u):$(id -g) $HOME/.kube/config
Deploy a pod network to the cluster
root@k8smaster:~$ kubectl create -f calico.yaml
Check running pods
root@k8smaster:~# kubectl -n kube-system get pods NAME READY STATUS RESTARTS AGE calico-kube-controllers-6b9d4c8765-p9wn7 1/1 Running 0 52s calico-node-bgklp 1/1 Running 0 52s coredns-5644d7b6d9-fmbsb 1/1 Running 0 71s coredns-5644d7b6d9-tdn9f 1/1 Running 0 71s etcd-k8smaster 1/1 Running 0 13s kube-apiserver-k8smaster 1/1 Running 0 30s kube-controller-manager-k8smaster 1/1 Running 0 19s kube-proxy-kknp8 1/1 Running 0 71s kube-scheduler-k8smaster 1/1 Running 0 32s
Join any number of worker nodes by running the following on each as root:
cd ../k8sworker1 vagrant ssh sudo -i
Get the following information out of the kubeadm-init.out for joining the worker in the cluster.
kubeadm join k8smaster:6443 --token pzybeg.5ebv6ct0ts7q0dde \ --discovery-token-ca-cert-hash sha256:b8bac2cb45f9e1e1c9db53dded9be20b3304462dc2586fe7ad5418e034013a58 cd ../k8slb vagrant ssh sudo -i docker run -d --restart=unless-stopped --name nginx -p 80:80 -p 443:443 -v /home/vagrant/nginx/nginx.conf:/etc/nginx/nginx.conf nginx:latest
Lens is the only IDE you’ll ever need to take control of your Kubernetes clusters. It is a standalone application for MacOS, Windows and Linux operating systems. It is open source and free. You can read more about Lens in our earlier blogpost about it. After you have installed Lens you can connect to your cluster using the Kubernetes config file, the only thing you have to do is change:
“server: https://k8smaster:6443” to “server: https://192.168.33.20:6443”
On k8smaster get the config file:
vagrant@k8smaster:~$ sudo cat /root/.kube/config
Start Lens and add the config file, don’t forget to change the server into https://192.168.33.20:6443.
After you have added the clusters you will see something like this:
Learning and starting with Kubernetes clusters on your local device with Lens is fun and a good starting point to experiment with Kubernetes.
Good luck and feel free to reach out in the comments if you have any questions or ideas.