Kubernetes Cluster on Vagrant

In this tutorial we will cover the installation of a Kubernetes Cluster over 3 virtual machines spawned using Virtualbox and Vagrant. This can be also useful to install Kubernetes over Bare Metal server or any sort of Virtual Machines as well.

Assumptions

• Vagrant and Virtualbox are already installed.
• We have 3 Centos 7 virtual machines running.

Pre-requisites

• Set the host-names for all 3 machines with the below commands
• sudo hostnamectl set-hostname kubem
• sudo hostnamectl set-hostname worker1
• sudo hostnamectl set-hostname worker2
• Disable selinux
• set selinux 0
• edit the file /etc/sysconfig/selinux and disable selinux
or use the below command directly to disable selinux
• sudo sed -i s/^SELINUX=.*$/SELINUX=disabled/ /etc/selinux/config
• Disable swap memory
• swapoff -a
• vim /etc/fstab
or
• sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
• Set net bridge for proper traffic routing
• cat < /etc/sysctl.d/k8s.conf net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 EOF
• Reload sysctl
• sysctl --system
• Set DNS entries in /etc/hosts
• 192.168.10.60 kubem
• 192.168.10.61 worker1
• 192.168.10.62 worker2
• Docker Installation
• yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
• yum update -y
• yum install -y yum-utils device-mapper-persistent-data lvm2 -y
• sudo yum install docker-ce -y
• sudo yum install docker-ce -y
• systemctl enable docker
• systemctl start docker
• systemctl status docker
• systemctl status docker
• docker version
• docker info
• Installing kubelet, kubeadm, kubectl
• cat < /etc/yum.repos.d/kubernetes.repo [kubernetes] name=Kubernetes baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64 enabled=1 gpgcheck=1 repo_gpgcheck=1 gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg EOF
• yum install -y kubelet-1.15.1 kubeadm-1.15.1
• systemctl enable kubelet
• systemctl start kubelet
• Initialize the kubernetes cluster
• kubeadm init --apiserver-advertise-address=172.31.19.193 --pod-network-cidr=10.244.0.0/16 --service-cidr=10.244.0.0/12
• Become Non-root user
• mkdir -p $HOME/.kube
• sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
• sudo chown $(id -u):$(id -g) $HOME/.kube/config
• Creating the CNI and Dashboard:
• kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
• kubectl create -f https://raw.githubusercontent.com/kubernetes/dashboard/master/aio/deploy/recommended/kubernetes-dashboard.yaml
• kubectl -n kube-system edit service kubernetes-dashboard
change from ClusterIP to NodePort
• kubectl describe services kubernetes-dashboard -n kube-system
• kubectl -n kube-system get secret
• kubectl -n kube-system describe secret namespace-contoller-token-xyxyx
now use this token to login to the cluster IP