DevOps Classroomnotes 30/Nov/2022

Kubernetes Installations

• K8s has many installation options
  • single node k8s cluster
    • k3c
    • kind
    • minikube
  • Multi node k8s cluster
    • manual installations:
      • kube-adm Refer Here
      • kube-spray Refer Here
      • kops Refer Here
      • MicroK8s
    • kubernetes as a service: Refer Here
      • aws => EKS (Elastic Kubernetes Services)
      • azure => AKS (Azure Kubernetes Service)
      • gcp => GKE (Google Kubernetes Engine)

Installing k8s using kube-adm

• Lab Setup
  
• Ports to be opened Refer Here
• Choose machines with atleast 2 vcpus and 2 GB of RAM
• Our runtime is Docker Refer Here
• Steps:
  • Install docker Refer Here
  • Install cri-dockerd

Install cri-dockerd

• To install cri-dockerd we need git and go
• Installing go Refer Here

###Install GO###
wget https://storage.googleapis.com/golang/getgo/installer_linux
chmod +x ./installer_linux
./installer_linux
source ~/.bash_profile

• Steps

sudo -i

###Install GO###
wget https://storage.googleapis.com/golang/getgo/installer_linux
chmod +x ./installer_linux
./installer_linux
source ~/.bash_profile
git clone https://github.com/Mirantis/cri-dockerd.git
cd cri-dockerd
mkdir bin
go build -o bin/cri-dockerd
mkdir -p /usr/local/bin
install -o root -g root -m 0755 bin/cri-dockerd /usr/local/bin/cri-dockerd
cp -a packaging/systemd/* /etc/systemd/system
sed -i -e 's,/usr/bin/cri-dockerd,/usr/local/bin/cri-dockerd,' /etc/systemd/system/cri-docker.service
systemctl daemon-reload
systemctl enable cri-docker.service
systemctl enable --now cri-docker.socket

• Now install the following components on all the nodes in the cluster https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#installing-kubeadm-kubelet-and-kubectl

sudo apt update
sudo apt-get install -y apt-transport-https ca-certificates curl
sudo curl -fsSLo /etc/apt/keyrings/kubernetes-archive-keyring.gpg https://packages.cloud.google.com/apt/doc/apt-key.gpg
echo "deb [signed-by=/etc/apt/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | 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

• To create a cluster, login into master node and execute the following Refer Here

sudo -i
kubeadm init --pod-network-cidr=10.244.0.0/16

• while initializing we got an error w.r.t to multiple CRI endpoints we need to set the right one
  
• We will fix this and initialize cluster in next session

k8s playground

• Refer Here to access
• To work with k8s without installation