Deploy kubernetes cluster with kubeadm

# run on all nodes
 
cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
overlay
br_netfilter
EOF
 
sudo modprobe overlay
sudo modprobe br_netfilter
 
# sysctl params required by setup, params persist across reboots
cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables  = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.ipv4.ip_forward                 = 1
EOF
 
sudo sysctl --system
 
# Verify
lsmod | grep br_netfilter
lsmod | grep overlay
sysctl net.bridge.bridge-nf-call-iptables net.bridge.bridge-nf-call-ip6tables net.ipv4.ip_forward

# run on all nodes
 
# Add Docker's official GPG key:
sudo apt-get update
sudo apt-get install ca-certificates curl gnupg
sudo install -m 0755 -d /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
sudo chmod a+r /etc/apt/keyrings/docker.gpg
 
# Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
     sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
 
sudo apt-get update
 
# Install containerd
sudo apt-get install -y containerd.io
 
# Verify
systemctl status containerd.service

# run on all nodes
 
containerd config default | sudo tee /etc/containerd/config.toml
sudo sed -i 's/SystemdCgroup \= false/SystemdCgroup \= true/g' /etc/containerd/config.toml
sudo systemctl restart containerd
 
# Verify
# crictl ps -a

# run on all nodes
 
sudo apt-get install -y apt-transport-https ca-certificates curl gpg
 
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.28/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:/v1.28/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

# run on master node
 
#K8S_MASTER_1_IP=$(hostname -I)
sudo kubeadm init --pod-network-cidr=10.244.0.0/16
#--apiserver-advertise-address=${K8S_MASTER_1_IP}
 
# install metic server
kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml

# run on master node
 
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
 
# export KUBECONFIG=~/.kube/config
 
# deploy bash completion
kubectl completion bash | sudo tee /etc/bash_completion.d/kubectl
 
echo "alias k=kubectl" >> .bashrc 
echo "complete -o default -F __start_kubectl k" >> .bashrc 
 
# verify
kubectl get pod --all-namespaces

# run on master node
 
wget https://github.com/weaveworks/weave/releases/download/v2.8.1/weave-daemonset-k8s.yaml -qO /tmp/weave-daemonset-k8s.yaml
 
# todo: automate
#kubectl edit -n kube-system ds weave-net
vi /tmp/weave-daemonset-k8s.yaml
   ...
    spec:
      containers:
        env:
        - name: IPALLOC_RANGE
          value: 10.244.0.0/16
 
 
kubectl apply -f /tmp/weave-daemonset-k8s.yaml
 
# todo: fix crashed containers
# sudo reboot
 
# verify
kubectl get all --all-namespaces

# run on worker node
 
# get jon command on master
kubeadm token create --print-join-command
 
# get join command from the sudo kubeadm init command output
sudo kubeadm join 10.0.10.76:6443 --token ******** \
	--discovery-token-ca-cert-hash sha256:********
 
# Verify
kubectl get nodes

# run on master node
 
# verify
kubectl create deployment nginx --image nginx --replicas 2
kubectl expose deployment nginx --name nginx-service --type NodePort --port 80
 
kubectl get all
APP_PORT=$(kubectl get service nginx-service -o jsonpath='{.spec.ports[*].nodePort}');
curl 127.0.0.1:${APP_PORT}
 
kubectl delete deployment nginx
kubectl delete service nginx-service