Kubernetes Setup : Linux

 Kubernetes Environment  Setup

Note : Kubeadm is currently in strong development, hence it is not recommended in production.

1. sudo apt-get remove docker docker-engine docker.io
2. sudo apt-get update && sudo apt-get install  -y apt-transport-https  ca-certificates    curl      software-properties-common
3. curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
4. sudo apt-key fingerprint 0EBFCD88
5. sudo add-apt-repository  "deb [arch=amd64] https://download.docker.com/linux/ubuntu   $(lsb_release -cs)  stable"
6. sudo apt-get update && sudo apt-get install docker-ce=17.03.0~ce-0~ubuntu-xenial
7. cat << EOF > /etc/docker/daemon.json

{

"exec-opts": ["native.cgroupdriver=systemd"]

}

EOF

8. systemctl enable docker && systemctl start docker

           

                                    Kubernetes Installation

1. apt-get update && apt-get install -y apt-transport-https
2. curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
3. cat <<EOF >/etc/apt/sources.list.d/kubernetes.list

deb http://apt.kubernetes.io/ kubernetes-xenial main

EOF

4. apt-get update
5. apt-get install -y kubelet kubeadm kubectl
6. swapoff -a
7. kubeadm init --pod-network-cidr=10.244.0.0/16

Below steps will be generated once kubeadm init gets completed

mkdir -p $HOME/.kube

sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

sudo chown $(id -u):$(id -g) $HOME/.kube/config

##########################################################################

Note : A token will be generated similar to below format, this is used to join multiple VM's to kubernetes cluster ###################################################################

kubeadm join --token 408875.a2c451dee603262b 192.168.244.221:6443 --discovery-token-ca-cert-hash sha256:2dd1a79ba8d695486021ede4b357b1d0a5288a59162231c7c732c08c9179f493

Make Sure with the below command to check all services are Up and Running

1. kubectl taint nodes --all node-role.kubernetes.io/master-
2. kubectl get pods --all-namespaces

Creating Sample Application

Create  an Deployment ( keeps nodes up and running)  and a pod ( nothing but a collection of container or a single container)

1. kubectl run webserver --image=nginx
2. Exposing service

kubectl expose deployment webserver --port 80 --type LoadBalancer  --external-ip=192.168.244.221

3. curl -I http://externalip
4. kubeadm init pod-network-cidr=10.244.0.0/16 --skip-preflight-checks=true

Create Application with YAML (Recommended)

Ref:

https://kubernetes.io/docs/getting-started-guides/ubuntu/