Kubeadm Lab in Azure

This repo contains IaC scripts to quickly bootstrap an environemnt in Azure, with one master and two worker nodes, ready for the kubeadm lab.

Infra Setup

All three VMs are created with equal resources: Standard_D2as_v4 tier of Ubuntu 18.04-LTS.

Note: Remeber to stop the VMs when not used.

To deploy resource in terraform:

> terraform init
> terraform plan -out res.tfplan
> terraform apply res.tfplan

Todo

• Powershell to stop all VMs
• DIY jumpbox to replace Azure Bastion
• [ ] Ansible to stop all VMs - Blocked by Ansible issue with Azure Cloud Shell
• Check port requirements for NSG during the kubeadm lab

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Kubeadm lab

Note: All VMs means master and nodes.

Step 1 SSH into master and nodes

Establish SSH connection to master and nodes VMs using jumpbox. eg. using putty to create 3 sessions.

Step 2 Update apt packages and PPAs, then install Docker CE (All VMs)

sudo apt-get update
sudo apt install docker.io -y
sudo systemctl enable docker

Step 3 Add Kubeadm repo and install kubeadm, kubectl and kubelet (All VMs)

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add
sudo apt-add-repository "deb http://apt.kubernetes.io/ kubernetes-xenial main"
sudo apt install -y kubeadm=1.18.1-00 kubelet=1.18.1-00 kubectl=1.18.1-00

Step 4 Initialize Kubeadm on master (Master only)

sudo kubeadm init --kubernetes-version=1.18.1

Keep the generated command: eg.

kubeadm join 10.0.0.4:6443 --token t299v2.c8vcbm33kfi1x0nt \
    --discovery-token-ca-cert-hash sha256:a5b1372829885851ca72ec1502414460c2ed5124e83704c8c07b3d49b137a229

Step 5 Enable kubectl command on master without root access (Master only)

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

Step 6 Join worker nodes to cluster (Nodes only)

sudo kubeadm join 10.0.0.4:6443 --token t299v2.c8vcbm33kfi1x0nt \
    --discovery-token-ca-cert-hash sha256:a5b1372829885851ca72ec1502414460c2ed5124e83704c8c07b3d49b137a229

Step 7 Install one of the CNI plugin on master (Master only)

Option: Calico

kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml

Option: Weave net CNI

kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"

Step 8 Verify K8s working (Master only)

[watch] kubectl get nodes
[watch] kubectl get pods --all-namespaces

References

• https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/
• https://docs.projectcalico.org/getting-started/kubernetes/quickstart
• https://help.mayadata.io/hc/en-us/articles/360036744451-Creating-an-unmanaged-Kubernetes-cluster-in-Azure-using-kubeadm