K8s master and Node Components
- Refer Here for master and node components
- Refer Here for official docs
K8s master components
- kube-apiserver:
- etcd
- kube-scheduler
- Controller Manager
- Cloud-Controller-Manager
k8s node components
- kubelet
- Container run-time
- Kube-proxy
Pods
- A pod is unit of work in k8s.
- Each pod contains one or more containers.
- Every pod gets unique ip address and the containers in the pod have same ip address.
K8s Installations
- K8s has many ways of installations.
- Installing k8s with deployment tools Refer Here
- Turnkey k8s Solutions Refer Here
- kubernetes for local laptop/single workstation Refer Here. Use this only for dev environmets
Kubeadm installation
- Refer Here for devops blog installation steps
- Refer Here for official documentation
- Install docker and kubeadmin,kubectl on all the three servers as mentioned in above documentation. Now login into master and execute as Refereed Over Here
kubeadm init
- Make node kubeadm init commands login as normal user and create .kube folder and config
Your Kubernetes control-plane has initialized successfully!
To start using your cluster, you need to run the following as a regular user:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
https://kubernetes.io/docs/concepts/cluster-administration/addons/
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join 172.31.20.190:6443 --token pvx7ty.3vwwzeads1sjd5v3 \
--discovery-token-ca-cert-hash sha256:b3d18743efe7230368b7ad3404bfa4e534bed0467cf79391d676f9f1082aa485
- Now Apply pod network
kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"
- Now join two nodes to cluster by executing kubeadm join command shown above
- After joining nodes, login into master and execute kubectl get nodes
