kubeadm-master.sh

#!/bin/sh

# Source: http://kubernetes.io/docs/getting-started-guides/kubeadm

set -e

source /etc/lsb-release
if [ "$DISTRIB_RELEASE" != "20.04" ]; then
    echo "################################# "
    echo "############ WARNING ############ "
    echo "################################# "
    echo
    echo "This script only works on Ubuntu 20.04!"
    echo "You're using: ${DISTRIB_DESCRIPTION}"
    echo "Better ABORT with Ctrl+C. Or press any key to continue the install"
    read
fi

KUBE_VERSION=1.25.5
CNI_Plugin="calico" # use calico or flannel
POD_NETWORK_CIDR="10.244.0.0/16" #to be used by CNI plugin

# Convert CNI to lower case to be used by the if statement
CNI_Plugin=$(echo "$CNI_Plugin" | tr '[:upper:]' '[:lower:]')

### setup terminal
apt-get update
apt-get -y upgrade
apt-get install -y bash-completion binutils
echo 'colorscheme ron' >> ~/.vimrc
echo 'set tabstop=2' >> ~/.vimrc
echo 'set shiftwidth=2' >> ~/.vimrc
echo 'set expandtab' >> ~/.vimrc
echo 'source <(kubectl completion bash)' >> ~/.bashrc
echo 'alias k=kubectl' >> ~/.bashrc
echo 'alias c=clear' >> ~/.bashrc
echo 'complete -F __start_kubectl k' >> ~/.bashrc


### disable linux swap and remove any existing swap partitions
swapoff -a
sed -i '/\sswap\s/ s/^\(.*\)$/#\1/g' /etc/fstab


### remove packages
kubeadm reset -f || true
crictl rm --force $(crictl ps -a -q) || true
apt-mark unhold kubelet kubeadm kubectl kubernetes-cni || true
apt-get remove -y docker.io containerd kubelet kubeadm kubectl kubernetes-cni || true
apt-get autoremove -y
systemctl daemon-reload



### install packages
curl https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
cat <<EOF > /etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
EOF
apt-get update
apt-get install -y docker.io containerd kubelet=${KUBE_VERSION}-00 kubeadm=${KUBE_VERSION}-00 kubectl=${KUBE_VERSION}-00 kubernetes-cni
apt-mark hold kubelet kubeadm kubectl kubernetes-cni


### containerd
cat <<EOF | sudo tee /etc/modules-load.d/containerd.conf
overlay
br_netfilter
EOF
sudo modprobe overlay
sudo modprobe br_netfilter
cat <<EOF | sudo tee /etc/sysctl.d/99-kubernetes-cri.conf
net.bridge.bridge-nf-call-iptables  = 1
net.ipv4.ip_forward                 = 1
net.bridge.bridge-nf-call-ip6tables = 1
EOF
sudo sysctl --system
sudo mkdir -p /etc/containerd


### containerd config
cat > /etc/containerd/config.toml <<EOF
disabled_plugins = []
imports = []
oom_score = 0
plugin_dir = ""
required_plugins = []
root = "/var/lib/containerd"
state = "/run/containerd"
version = 2
[plugins]
  [plugins."io.containerd.grpc.v1.cri".containerd.runtimes]
    [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
      base_runtime_spec = ""
      container_annotations = []
      pod_annotations = []
      privileged_without_host_devices = false
      runtime_engine = ""
      runtime_root = ""
      runtime_type = "io.containerd.runc.v2"
      [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
        BinaryName = ""
        CriuImagePath = ""
        CriuPath = ""
        CriuWorkPath = ""
        IoGid = 0
        IoUid = 0
        NoNewKeyring = false
        NoPivotRoot = false
        Root = ""
        ShimCgroup = ""
        SystemdCgroup = true
EOF


### crictl uses containerd as default
{
cat <<EOF | sudo tee /etc/crictl.yaml
runtime-endpoint: unix:///run/containerd/containerd.sock
EOF
}


### kubelet should use containerd
{
cat <<EOF | sudo tee /etc/default/kubelet
KUBELET_EXTRA_ARGS="--container-runtime remote --container-runtime-endpoint unix:///run/containerd/containerd.sock"
EOF
}



### start services
systemctl daemon-reload
systemctl enable containerd
systemctl restart containerd
systemctl enable kubelet && systemctl start kubelet


### init k8s
rm /root/.kube/config || true
kubeadm init --kubernetes-version=${KUBE_VERSION} --ignore-preflight-errors=NumCPU --skip-token-print --pod-network-cidr ${POD_NETWORK_CIDR}

mkdir -p ~/.kube
sudo cp -i /etc/kubernetes/admin.conf ~/.kube/config


### CNI
if [ "$CNI_Plugin" = "Calico" ]
then
  kubectl create -f https://raw.githubusercontent.com/projectcalico/calico/v3.25.1/manifests/tigera-operator.yaml
  curl https://raw.githubusercontent.com/projectcalico/calico/v3.25.1/manifests/custom-resources.yaml -O
  sed -i "s|cidr: .*|cidr: ${POD_NETWORK_CIDR}|" custom-resources.yaml
  kubectl apply -f ./custom-resources.yaml
  rm -rf ./custom-resources.yaml
elif [ "$CNI_Plugin" = "Flannel" ]
then
  kubectl apply -f https://raw.githubusercontent.com/flannel-io/flannel/master/Documentation/kube-flannel.yml
else
  echo "Invalid CNI Plugin choice: should be either 'Calico' or 'Flannel'"
fi

# install MetalLB
kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.13.9/config/manifests/metallb-native.yaml
echo "### installing MetalLB ###"
echo "### Configure MetalLB with l2 by applying the below yaml###"

cat <<EOF | kubectl apply -f -
apiVersion: metallb.io/v1beta1
kind: IPAddressPool
metadata:
  name: first-pool
  namespace: metallb-system
spec:
  addresses:
  - 10.210.255.100-10.210.255.200
EOF

cat << EOF | kubectl apply -f -
apiVersion: metallb.io/v1beta1
kind: L2Advertisement
metadata:
  name: example
  namespace: metallb-system
EOF

# etcdctl
ETCDCTL_VERSION=v3.5.1
ETCDCTL_VERSION_FULL=etcd-${ETCDCTL_VERSION}-linux-amd64
wget https://github.com/etcd-io/etcd/releases/download/${ETCDCTL_VERSION}/${ETCDCTL_VERSION_FULL}.tar.gz
tar xzf ${ETCDCTL_VERSION_FULL}.tar.gz
mv ${ETCDCTL_VERSION_FULL}/etcdctl /usr/bin/
rm -rf ${ETCDCTL_VERSION_FULL} ${ETCDCTL_VERSION_FULL}.tar.gz


#taint master node
echo "### Taint master node with criticaladdon ###"
kubectl taint nodes $(echo $(hostname) | tr '[:upper:]' '[:lower:]') CriticalAddonsOnly=true:NoExecute

echo
echo "### COMMAND TO ADD A WORKER NODE ###"
kubeadm token create --print-join-command --ttl 0