Simple shell script to initialize the first k8s master. This was needed, because of some networking discrepancies with minikube testing in relation to a production cluster. This allows you to fire up a single node master/worker, single master multiple workers, or HA k8s via kubeadm. Installs Flannel and MetalLB (cause layer2 for local devel)

master01_init.sh

#!/bin/bash
# Simple shell script to initialize the first k8s master. 
# This was needed, because of some networking discrepancies with minikube testing in relation to a production cluster. 
# This allows you to fire up a single node master/worker, single master multiple workers, or HA k8s via kubeadm. 
# Installs Flannel and MetalLB (cause layer2 for local devel)
# Pardon my terrible shell coding skills. Whipped this up on a late night.

### Settings ###

FLANNEL_MANIFEST="https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml"
METALLB_MANIFEST="https://raw.githubusercontent.com/google/metallb/v0.8.3/manifests/metallb.yaml"

# Any out-of-the-box manifests you'd like to apply from the start.
APP_MANIFESTS="~/manifests"

### DO NOT EDIT BELOW THIS LINE UNLESS YOU KNOW WHAT YOU ARE DOING ###

# Reset existing cluster (if any)
echo "Cleaning up existing installs (if any)..."

sudo kubeadm reset -f > /dev/null 2>&1

# Cleanup
sudo rm -rf /var/lib/etcd
sudo rm -rf /var/lib/kubelet
sudo rm -rf /etc/kubernetes
sudo rm -rf /home/$USER/.kube
sudo rm -rf /root/.kube


IP=$(hostname --all-ip-addresses | awk '{print $1;}')

# Create cluster.yaml
cat <<EOF >/tmp/cluster.yaml
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: k8s.gcr.io
kind: ClusterConfiguration
controlPlaneEndpoint: $IP:6443
networking:
  dnsDomain: cluster.local
  podSubnet: 10.244.0.0/16
  serviceSubnet: 10.96.0.0/12
scheduler: {}
apiServer:
  extraArgs:
    authorization-mode: Node,RBAC
  timeoutForControlPlane: 4m0s
EOF

# Collect informationi

HA=false
OTHER_MASTERS_IPS=()
OTHER_MASTERS_NAMES=()
whiptail --title "Untaint Master?" --yesno --defaultno "Untaint Master for single node operation?" 8 78
TAINT=$?


if [ $TAINT = 1 ]; then
  if (whiptail --title "HA Deployment?" --yesno "Is this a High-Availability Cluster?" 8 78 ); then
    HA=true
    while (true); do
       NEXT_MASTER=$(whiptail --inputbox "Additional Master IP (Empty for finished)" 8 78 --title "Additional Master IP" 3>&1 1>&2 2>&3)
       if [[ $NEXT_MASTER = "" ]]; then
         break
       fi
       NEXT_MASTER_NAME=$(whiptail --inputbox "$NEXT_MASTER FQDN for API Certificate" 8 78 --title "$NEXT_MASTER FQDN" 3>&1 1>&2 2>&3)
       OTHER_MASTERS_IPS+=($NEXT_MASTER)
       OTHER_MASTERS_NAMES+=($NEXT_MASTER_NAME)
    done

    HA_API_IP=$(whiptail --inputbox "HA API IP Address" 8 78 --title "HA API IP Address" 3>&1 1>&2 2>&3)
    HA_API_FQDN=$(whiptail --inputbox "HA API FQDN" 8 78 --title "HA API FQDN" 3>&1 1>&2 2>&3)

    echo "  certSANs:" >> /tmp/cluster.yaml
    for i in $OTHER_MASTERS_IPS; do
      echo "    - $i" >> /tmp/cluster.yaml
    done

    for i in $OTHER_MASTERS_NAMES; do
      echo "    - $i" >> /tmp/cluster.yaml
    done

    echo "    - $HA_API_IP" >> /tmp/cluster.yaml
    echo "    - $HA_API_FQDN" >> /tmp/cluster.yaml

  fi
fi

# Initialize Cluster

sudo kubeadm init --config=/tmp/cluster.yaml

echo "Copying kubeconfig..."
sudo mkdir -p /home/$USER/.kube
sudo cp -i /etc/kubernetes/admin.conf /home/$USER/.kube/config
sudo chown $USER:$USER /home/$USER/.kube/config

if [ $TAINT = 0 ]; then
  echo "Untainting Master..."
  kubectl taint nodes --all node-role.kubernetes.io/master-
fi

echo "Installing Flannel..."
kubectl apply -f $FLANNEL_MANIFEST
echo "Installing MetalLB..."
kubectl apply -f $METALLB_MANIFEST

START_IP=$(whiptail --inputbox "Starting LoadBalancer Range Address" 8 78 --title "MetalLB Configuration" 3>&1 1>&2 2>&3)
END_IP=$(whiptail --inputbox "Ending LoadBalancer Range Address" 8 78 --title "MetalLB Configuration" 3>&1 1>&2 2>&3)

if ($HA); then
  cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: ConfigMap
metadata:
  namespace: metallb-system
  name: config
data:
  config: |
    address-pools:
    - name: default
      protocol: layer2
      addresses:
      - $START_IP-$END_IP
    - name: ha-api
      protocol: layer2
      addresses:
      - $HA_API_IP-$HA_API_IP
EOF

# There is probably a much better way to do this, but I am no bash coder

  cat <<EOF >/tmp/nginx-ha-api-proxy.yaml
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: nginx-ha-api-proxy
  namespace: kube-system
data:
  nginx.conf: |
    error_log stderr notice;

    worker_processes auto;
    events {
      multi_accept on;
      use epoll;
      worker_connections 1024;
    }

    stream {
      upstream kube_apiserver {
EOF
  echo "        server $IP:6443;" >> /tmp/nginx-ha-api-proxy.yaml
  for i in $OTHER_MASTERS_IPS; do
    echo "        server $i:6443;" >> /tmp/nginx-ha-api-proxy.yaml
  done

  cat <<EOF >>/tmp/nginx-ha-api-proxy.yaml
      }

      server {
        listen        6443;
        proxy_pass    kube_apiserver;
        proxy_timeout 30;
        proxy_connect_timeout 2s;
      }
    }
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: nginx-ha-api-proxy
  namespace: kube-system
spec:
  selector:
    matchLabels:
      app: nginx-ha-api-proxy
  template:
    metadata:
      labels:
        app: nginx-ha-api-proxy
    spec:
      containers:
        - name: nginx
          image: nginx
          volumeMounts:
            - name: config-volume
              mountPath: /etc/nginx
          ports:
            - containerPort: 6443
      volumes:
        - name: config-volume
          configMap:
            name: nginx-ha-api-proxy
      restartPolicy: Always
---
apiVersion: v1
kind: Service
metadata:
  name: nginx-ha-api-proxy
  namespace: kube-system
  annotations:
    metallb.universe.tf/address-pool: ha-api
spec:
  sessionAffinity: ClientIP
  selector:
    app: nginx-ha-api-proxy
  type: LoadBalancer
  ports:
    - protocol: TCP
      port: 443
      targetPort: 6443
EOF
  kubectl apply -f /tmp/nginx-ha-api-proxy.yaml

else
  cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: ConfigMap
metadata:
  namespace: metallb-system
  name: config
data:
  config: |
    address-pools:
    - name: default
      protocol: layer2
      addresses:
      - $START_IP-$END_IP
EOF
fi

echo "Applying Application Manifests..."
kubectl apply -f $APP_MANIFESTS/

echo -e "\n\n\n\n"
echo "Finished! It can take up to 2 minutes for the cluster to finish coming up."
if [ $HA = true ]; then
  sudo tar cfz certs.tar.gz /etc/kubernetes/pki/ca.{crt,key} /etc/kubernetes/pki/sa.{pub,key} /etc/kubernetes/pki/front-proxy-ca.{crt,key} /etc/kubernetes/pki/etcd/ca.{crt,key} > /dev/null 2>&1
  echo "Copy $(pwd)/certs.tar.gz to remaining masters, extract with \`sudo tar xvfz certs.tar.gz -C /\`, then join the masters using the above join command with --control-plane"
fi


if [ $TAINT = 1 ]; then
  echo "You may now use the join command above to join additional workers."
fi