Create a Kubernetes Docker Cluster on Ubuntu Server
12#Docker #Kubernetes #Ubuntu
Full steps can be found at https://i12bretro.github.io/tutorials/0421.html
Preparing the VMs
Log into a freshly installed Ubuntu VM
01. Run the following commands
# set the hostname
sudo hostnamectl set-hostname kubernetes
# update hosts file
sudo nano /etc/hosts
02. Update the 127.0.01 to the new hostname, kubernetes
03. Press CTRL+O, Enter, CTRL+X to write the changes to hosts
04. Continue with the following commands
# disable the firewall
sudo ufw disable
# disable the swap file
sudo swapoff -a
# disable swap partition
sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
sudo echo "vm.swappiness=0" | sudo tee --append /etc/sysctl.conf
# update sysctl networking
cat ≪ net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sudo sysctl --system
# apply the changes
sudo sysctl -p
Installing Docker
Continue with the following commands in terminal # install prerequisites
sudo apt install apt-transport-https ca-certificates curl software-properties-common gnupg-agent -y
# add docker gpg key
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
# add docker software repository
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
# install docker
sudo apt install docker-ce docker-compose containerd.io -y
# enable and start docker service
sudo systemctl enable docker && sudo systemctl start docker
# add the current user to the docker group
sudo usermod -aG docker $USER
# reauthenticate for the new group membership to take effect
su - $USER
Installing Kubernetes
Continue with the following commands in terminal # add kubernetes gpg key
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
# add the kubernetes software repo
echo 'deb http://apt.kubernetes.io/ kubernetes-xenial main' | sudo tee /etc/apt/sources.list.d/kubernetes.list
# update software repositories
sudo apt update
# install kubernetes
sudo apt install kubelet kubeadm kubectl -y
# shutdown the VM
sudo shutdown now
Cloning the VirtualBox VM
In VirtualBox Manager, right click on the Kubernetes VM ≫ Clone...
01. Name the cloned VM Docker1 ≫ Click Next
02. Make sure Full Clone is selected ≫ Click Clone
03. In VirtualBox Manager, right click on the Ubuntu VM again ≫ Clone...
04. Name the cloned VM Docker2 ≫ Click Next
05. Make sure Full Clone is selected ≫ Click Clone
06. Right click the Kubernetes VM ≫ Start ≫ Normal Start
07. Right click the Docker1 VM ≫ Start ≫ Normal Start
08. Once the VM boots, log in and run the following commands
# set the hostname
sudo hostnamectl set-hostname docker1
# update hosts file
sudo nano /etc/hosts
09. Update the 127.0.01 to the new hostname, docker1
10. Press CTRL+O, Enter, CTRL+X to write the changes to hosts
11. Reboot the VM with the following command
sudo reboot now
12. Back in VirtualBox Manager, right click the Docker2 VM ≫ Start ≫ Normal Start
13. Once the VM boots, log in and run the following commands
# set the hostname
sudo hostnamectl set-hostname docker2
# update hosts file
sudo nano /etc/hosts
14. Update the 127.0.01 to the new hostname, docker2
15. Press CTRL+O, Enter, CTRL+X to write the changes to hosts
16. Reboot the VM with the following command
sudo reboot now
17. At this point we have 3 Ubuntu VMs (kubernetes, docker1, docker2) running with swap disabled and docker and kubernetes installed
18. All 3 VMs will need static IP addresses, I prefer to create static DHCP leases on my router for a single point of configuration, but the VM IP addresses can be set with the following command if needed
sudo nano /etc/netplan/01-installer-config.yaml
19. Set DHCP4 = no and update the IP address, gateway and nameservers
dhcp4: no
addresses: [192.168.100.100/24]
gateway4: 192.168.100.1
nameservers:
addresses: [192.168.100.1,8.8.8.8]
Configuring the Kubernetes Cluster
Follow the steps below only on the kubernetes VM
Log into the kubernetes VM and run the following commands in terminal # initialize the cluster, copy the kubeadm join command for use later when joining the docker hosts to the cluster
....Full steps can be found on GitHub [link at the top]
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