Kubernetes :- The Production grade container orchestration Engine

Kubernetes multinode setup

we have 3 machines; 1 master and 2 worker nodes

Pre-requisite

• amazon linux 2 OS
• master t2.medium and worker t2.micro

Installing docker in all the nodes

yum  install  docker  -y

now install kubeadm and configure yum

you can browse this link kubernetes repo

or yum can be configured by running this command

cat <<EOF | sudo tee /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://pkgs.k8s.io/core:/stable:/v1.30/rpm/
enabled=1
gpgcheck=1
gpgkey=https://pkgs.k8s.io/core:/stable:/v1.30/rpm/repodata/repomd.xml.key
exclude=kubelet kubeadm kubectl cri-tools kubernetes-cni
EOF

now run

yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes --disableplugin=priorities

Start service of docker & kubelet in all the nodes

systemctl enable --now  docker kubelet

for kernel configuration and ip tables

modprobe br_netfilter

echo '1' > /proc/sys/net/ipv4/ip_forward

echo 1 > /proc/sys/net/bridge/bridge-nf-call-iptables

Do this only on Kubernetes Master

We are here using Calico Networking, so we need to pass some parameter you can start Kubernetes_networking from this

kubeadm  init --pod-network-cidr=192.168.0.0/16

In case of cloud services like aws, azure if want to bind public with certificate of kubernetes

kubeadm init --pod-network-cidr=192.168.0.0/16 --apiserver-advertise-address=0.0.0.0   --apiserver-cert-extra-sans=publicip,privateip,serviceip

Use the output of above command and paste it to all the worker nodes

Do this step in master node

mkdir -p $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config

Now apply calico project

kubectl apply -f https://raw.githubusercontent.com/projectcalico/calico/v3.25.0/manifests/calico.yaml

Installing calico in minikube cluster..

minikube start --network-plugin=cni --cni=calico

ADding new node in minikube

  minikube node add

After this all nodes will be in ready state

Now you can check nodes status

[root@master ~]# kubectl get node
NAME     STATUS   ROLES           AGE     VERSION
master   Ready    control-plane   18h     v1.28.0
w1       Ready    <none>          18h     v1.28.0
w2       Ready    <none>          2m37s   v1.28.0