Kubernetes from Scratch on GCP: A learning excercise.

The scripts in this repo will create a functioning kubernetes installation with popular components. It's meant to be executed one by one, such that a person can try to understand each step in the process. To execute all of them and simply get a running k8s cluster simply run the run_all.sh script.

Initialize/pave some infrastructure in GCP:

• Create a VPC network called kubenet
• Create a subnet called kubenet-subnet (172.16.0.0/24)
• Create firewall rules (tcp:22 (ssh) tcp:6443 (kubeapi))
• Boot 3 Ubuntu 18.04 VM's

  $ bash 01-configure-gcp.sh

Setup DNS

• Add an entry for each cluster node to each VM's /etc/hosts file

  $ bash 02-configure-dns.sh

Install docker on all cluster nodes.

• Install docker
• Update docker config to use systemd for cgroup management
• Create internal subnet for docker (172.17.0.0/16)
• Create interface docker0 (ifconfig docker0) 172.17.0.1
• Add routes for docker subnet 172.17.0.0/16 -> docker0
• Create iptables rules for networking

  $ bash 03-install-docker.sh

Install k8s utilities

• Install kubelet, kubeadm, kubectl on all cluster nodes.

  $ bash 04-install-kubeadm.sh

Install cluster master components:

https://kubernetes.io/docs/concepts/overview/components/#master-components

• Run kubeadm init
  • Setup kubectl access for default user
  • Add external kube-master VM IP to SSL Cert
  • kubeadm init (start kube-system master processes)
    • Boot kube-system containers:
      • kube-system coredns
      • kube-system etcd-kube-master
      • kube-system kube-apiserver-kube-master
      • kube-system kube-controller-manager-kube-master
      • kube-system kube-proxy
      • kube-system kube-scheduler-kube-master
  • Install kube-flannel for overlay network (10.244.0.0/16)
    • https://github.com/coreos/flannel/blob/master/Documentation/kubernetes.md
    • Create security policy, cluster role, role binding and service account.
    • API Extensions added for flannel
    • Start flannel container on the master
      • kube-system kube-flannel
  • Add kube-worker-1 and kube-worker-2 to the cluster
    • Starts 4 docker containers on the worker nodes
      • k8s_kube-flannel_kube-flannel
      • k8s_kube-proxy_kube-proxy
      • k8s_POD_kube-proxy
      • k8s_POD_kube-flannel
    • Adds interface and routes for: flannel.1
      • kube-master (10.244.0.0/32)
      • kube-worker-1 (10.244.1.0/32)
      • kube-worker-2 (10.244.2.0/32)

  $ bash 05-configure-kubeadm.sh

Enable remote access for kubectl

  $ bash 06-configure-kubectl.sh

Deploy the k8s Dashboard, create admin user and issue a token

  $ bash 07-install-dashboard.sh

Setup and deploy persistant disk volumes.

  $ bash 08-configure-storage.sh

Setup helm

  $ bash 09-install-helm.sh

Deploy a simple app (Linux desktop)

• Currently does nothing.

  $ bash 10-install-test-app.sh

Install Istio

  $ bash 11-install-istio.sh

Deploy Istio App and create FW rule.

  $ bash 12-install-istio-app.sh

To simply run everything, you can do:

  $ bash run_all.sh

Delete the entire deployment (wipe everything)

  $ 00-delete-deployment.sh