Modification history:
- September 7, 2023
- Add a default storageclass
- September 1, 2023:
- Update point 5 to get newer versions of docker
- Update point 6 with k8s version 1.28
This repository describes all the steps to install a local k8s cluster using Docker and Virtual Box.
Credits for Vagrantfile, update-dns.sh and setup-hosts.sh go to https://github.com/kodekloudhub/certified-kubernetes-administrator-course.
Clone this repository and open a terminal in the directory of the repository.
Change the Vagranfile to adapt the number of hosts and memory settings (default is 1 master node, 1 runner node, 2048M/node)
vagrant up
vagrant ssh kubemaster
vagrant ssh kubenode01
In the following chapter we follow instructions described in https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/
On each node check for the br_netfilter module. If not loaded, load the module:
lsmod | grep br_netfilter
sudo modprobe br_netfilter
Execute the script:
cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sudo sysctl --system
On each node install the cli, containerd and docker (we can change for newer versions)
The docker cli:
curl https://download.docker.com/linux/ubuntu/dists/focal/pool/stable/amd64/docker-ce-cli_24.0.5-1~ubuntu.20.04~focal_amd64.deb --output cli.deb
sudo dpkg -i cli.deb
Containerd:
curl https://download.docker.com/linux/ubuntu/dists/focal/pool/stable/amd64/containerd.io_1.6.9-1_amd64.deb --output containerd.deb
sudo dpkg -i containerd.deb
Docker:
curl https://download.docker.com/linux/ubuntu/dists/focal/pool/stable/amd64/docker-ce_24.0.5-1~ubuntu.20.04~focal_amd64.deb --output docker.deb
sudo dpkg -i docker.deb
On each node install kubeadm:
sudo apt-get update
sudo apt-get install -y apt-transport-https ca-certificates curl
On Ubuntu 20.04 /etc/apt/keyrings does not exist:
sudo mkdir -755 /etc/apt/keyrings
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.28/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
Add the Kubernetes apt repository:
echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.28/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
Update apt package index, install kubelet, kubeadm and kubectl, and pin their version:
sudo apt-get update
sudo snap install kubelet --classic
sudo snap install kubeadm --classic
sudo snap install kubectl --classic
sudo apt-mark hold kubelet kubeadm kubectl
**** Only on the master node ****
sudo su
rm /etc/containerd/config.toml
systemctl restart containerd
kubeadm init --pod-network-cidr 10.244.0.0/16 --apiserver-advertise-address=192.168.56.2
Keep the output of the command. This command will be executed later in each worker node.
Then as a regular user:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
Weave (https://www.weave.works/docs/net/latest/overview/) is used to define a virtual network between the docker containers.
Check that the master node is up and running:
kubectl get nodes
NAME STATUS ROLES AGE VERSION
kubemaster NotReady control-plane,master 6m53s v1.23.1
On the master node, get weave:
wget https://github.com/weaveworks/weave/releases/download/v2.8.1/weave-daemonset-k8s.yaml
Modify the definition to avoid the use of a Network Policy Controller (in order to allow access to the internet from the pods) and then apply the definition.
Set EXPECT_NPC to "0"
containers:
- name: weave
env:
- name: INIT_CONTAINER
value: "true"
- name: EXPECT_NPC
value: "0"kubectl apply -f weave-daemonset-k8s.yaml
On each worker node:
sudo su
rm /etc/containerd/config.toml
systemctl restart containerd
Then execute the command saved in step 7
Check that the worker nodes have joined the cluster
kubectl get nodes
NAME STATUS ROLES AGE VERSION
kubemaster Ready control-plane,master 12m v1.23.1
kubenode01 Ready <none> 51s v1.23.1
The k8s cluster is up and running.
You can add a default storageclass:
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: local-storage
annotations:
"storageclass.kubernetes.io/is-default-class": "true"
provisioner: kubernetes.io/no-provisioner
reclaimPolicy: Retain
allowVolumeExpansion: false
volumeBindingMode: WaitForFirstConsumerTo get access to the cluster from the host machine, merge the content of the .kube/config file into your local k8s config file.