from itsdangerous import TimedJSONWebSignatureSerializer as Serializer
s = Serializer(app.config['SECRET_KEY'], expires_in=3600)
token = s.dumps({ 'confirm': 10 })

data = s.loads(token)

• Subject: Installing Kubernetes using "Kubeadm" on "Ubuntu"

0. Provisioning Nodes and Firewalls:

0a. Kubernetes Cluster Nodes(3):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Cloud: Google Compute Engine (GCE)
Master(1): 2 vCPUs - 4GB Ram  
Worker(2): 2 vCPUs - 2GB RAM
OS:     Ubuntu 16.04 or CentOS/RHEL 7


0b. Firewall Rules (Ingress): 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Master Node: 2379,6443,10250,10251,10252 
Worker Node: 10250,30000-32767


0c. NOT Mandatory. For better visibility.
-----------------------------------------
Add below lines to ~/.bashrc
Master Node:
PS1="\e[0;33m[\u@\h \W]\$ \e[m "

Worker Node:
PS1="\e[0;36m[\u@\h \W]\$ \e[m "

***************************************************************************************************


1. PRE-Reqs: Disable Swap | Bridge Traffic (Run it on MASTER & WORKER Nodes):

1a) Disable SWAP:

swapoff -a
sed -i.bak -r 's/(.+ swap .+)/#\1/' /etc/fstab


1b) Bridge Traffic:

lsmod | grep br_netfilter sudo modprobe br_netfilter

cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf net.bridge.bridge-nf-call-ip6tables = 1 net.bridge.bridge-nf-call-iptables = 1 EOF

sudo sysctl --system

---

2. Installing Docker (Run it on MASTER & WORKER Nodes):

apt-get update  
apt-get install -y  apt-transport-https ca-certificates curl software-properties-common gnupg2

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
     $(lsb_release -cs) \
     stable"


2a) Installing Docker:
~~~~~~~~~~~~~~~~~~~~~
apt-get update && sudo apt-get install -y \
  containerd.io=1.2.13-2 \
  docker-ce=5:19.03.11~3-0~ubuntu-$(lsb_release -cs) \
  docker-ce-cli=5:19.03.11~3-0~ubuntu-$(lsb_release -cs)


2b) Setting up the Docker "daemon":
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cat <<EOF | sudo tee /etc/docker/daemon.json
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2"
}
EOF

mkdir -p /etc/systemd/system/docker.service.d


2c) Start and enable docker:
~~~~~~~~~~~~~~~~~~~~~~~~~~~
systemctl daemon-reload
systemctl enable docker
systemctl restart docker
systemctl status docker


***************************************************************************************************


3. Installing KUBEADM   - KUBELET -  KUBECTL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

apt-get update && sudo apt-get install -y apt-transport-https curl

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -

cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF


3a) Installing Kubeadm, Kubelet, Kubectl:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
apt-get update
apt-get install -y kubelet kubeadm kubectl

apt-mark hold kubelet kubeadm kubectl


3b) Start and enable Kubelet:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
systemctl daemon-reload
systemctl enable kubelet
systemctl restart kubelet
systemctl status kubelet


***************************************************************************************************


4. Initializing CONTROL-PLANE (Run it on MASTER Node only)

kubeadm init

---

5. Installing POD-NETWORK add-on (Run it on MASTER Node only)

5a) "kubectl":
~~~~~~~~~~~~~~
# for kubectl
mkdir -p $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config


5b) Installing "Weave CNI" (Pod-Network add-on):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"

NOTE: There are multiple CNI Plug-ins available. You can install choice of yours. Incase above commands doesn't work, try checking below link for more info.


***************************************************************************************************


6. Joining Worker Nodes (Run it on WORKER Node only):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

# Past the Join command from above kubeadm init output
kubeadm join <...>


# Run this command IF you do not have above join command and/or to create NEW one.
kubeadm token create --print-join-command 


***************************************************************************************************

NEXT: Validating Kubernetes Cluster

***************************************************************************************************