Creating and Managing K8s Cluster
- Admin Activities:
- Bootstrapping the control plane noe
- Bootstrapping the worker nodes
- upgrading cluster to new version
- The above activities, we will try to perform using
- kubeadm (certifications)
- AKS
- EKS
- GKE
kubeadm
- Cluster Installation process
- Lets try installing older version of kubernetes cluster using kubeadm
- We have installed docker and cri-dockerd version 0.34 by downloading deb from Refer Here
# These steps are executed on ubuntu 22.04
wget https://github.com/Mirantis/cri-dockerd/releases/download/v0.3.4/cri-dockerd_0.3.4.3-0.ubuntu-jammy_amd64.deb
sudo dpkg -i cri-dockerd_0.3.4.3-0.ubuntu-jammy_amd64.deb
- We have installed kubeadm with version 1.26
sudo apt-get update
# apt-transport-https may be a dummy package; if so, you can skip that package
sudo apt-get install -y apt-transport-https ca-certificates curl
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.26/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.26/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl
- Now try the steps as done in the class to bring up the cluster with 1.26
- Now lets try to create a deployment
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
labels:
app: nginx
spec:
replicas: 3
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.14.2
ports:
- containerPort: 80
- create a deployment
- Current version information
- Now we need to move to the next version
1.27 -
upgrade process
- Commands to upgrade control plane
sudo apt-mark unhold kubelet kubeadm kubectl
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.27/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.27/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo apt-get update
sudo apt-cache madison kubeadm
sudo apt-get install kubeadm=1.27.4-1.1 && sudo apt-mark hold kubeadm
kubeadm version
sudo kubeadm upgrade plan
sudo kubeadm upgrade apply v1.27.4
kubectl drain ip-172-31-33-86 --ignore-daemonsets
sudo apt-mark unhold kubelet kubectl && sudo apt-get install -y kubelet=1.27.4-1.1 kubectl=1.27.4-1.1 && sudo apt-mark hold kubelet kubectl
sudo systemctl daemon-reload
sudo systemctl restart kubelet.service
kubectl uncordon ip-172-31-33-86
kubectl get nodes
- Commands to upgrade worker node
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.27/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.27/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo apt-get update
sudo apt-mark unhold kubelet kubeadm kubectl
sudo apt-cache madison kubeadm
sudo apt-get install kubeadm=1.27.4-1.1 && sudo apt-mark hold kubeadm
sudo kubeadm upgrade node
kubectl get nodes
kubectl drain ip-172-31-40-43 --ignore-daemonsets
sudo apt-mark unhold kubelet kubectl && sudo apt-get install -y kubelet=1.27.4-1.1 kubectl=1.27.4-1.1 && sudo apt-mark hold kubelet kubectl
sudo systemctl daemon-reload
sudo systemctl restart kubelet.service
kubectl uncordon ip-172-31-40-43
* After upgrade
