Leveraging Google Cloud to Run Kubernetes

Here, some stream-of-consciousness and follow-along notes through a process of levering Google's google cloud setup to run a simple p.o.c k8s cluster.

An overview of the elements involved

• A VPC

  • a "virtual private cloud" network, "...a virtual version of a physical network, implemented inside of Google's production network..."

• 2 Vms

  • set one up as a k8s controlplane node
  • set one up as a k8s worker node

• Leveraging Google Cloud to Run Kubernetes

  • An overview of the elements involved
  • VM Hardware, OS, and Networking Configurations
    • GCE Config Details
  • VM K8s Setup
    • SSH Into the Machine
    • Perhaps a Screeching Halt
    • A Run-Around on Setting up K8s for a control Plane Node
    • A Run-Around on Setting up K8s for a worker Node

VM Hardware, OS, and Networking Configurations

Here are some per-vm config details to consider:

• 2 CPUs
• 8GB of Ram - a reasonably low amount
• 25GB of disk on the "master" controlplane node
• should be accessible by ss (and potentially http and https, we'll get there)

GCE Config Details

During my setup

• E2 series
• e2-standard-2 (2 vCPU, 8 GB memory)
• Automatic CPU Platform
• Boot Disk: 25gb, ubuntu 20.xx (LTS)
• Allowing some firewall details
• allow access to some cloud apis
• bunch of other details I did not care about, shot in the dark a bit here
• i named my "cp" to resemble "controlplane"

VM K8s Setup

Once the vm is "setup" by gce, ssh into the machine.

SSH Into the Machine

• navigate to the gce "console": This can be cumbersome and complicated if you've "messed around" a bit with this GCE setup - mine is a "compute engine"
• There will be a left-hand nav bar with "VM instances" - click that to see a "list" of vms... should be this one
• find the "row" that lists this single vm && find the Connect header - there should be a bold SSH in there - click that!!
• a new window popped up on mine after waiting a few seconds - thought the thing was broken

Perhaps a Screeching Halt

Give the kubernetes docs a shot at installing K8s on a GCE VM.
I followed some other directions.

A Run-Around on Setting up K8s for a control Plane Node

Download a bunch of needed tooling:

• kubelet
• kubeadm
• kubectl
• probably a few more bits too

More:

• Update the networking to allow traffic between soon-to-be-innards
• Install, setup, and start containerd
• initialize the controlplane node with kubeadm init
  • consider using the --pod-network-cidr cli option to specify a range of IPs for the pod network
• Setup the kubernetes root user
  • per the "Create a cluster with kubeadm" docs, in the "More Information" section

# make a dir to store the kube config file
mkdir -p $HOME/.kube


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

• consider some extra bits
  • a pod networking tool (something like calico)
  • helm (the kubernetes "package manager")
  • configure k8s bash autocompletion: source <(kubectl completion bash)
  • c

A Run-Around on Setting up K8s for a worker Node

Repeat all the steps from the contril plane node.
Those are, more or less, kubernetes setup directions.
Then, the control plane node can be used to provide a "join" command.
The "join" command will be used on the worker node to join the worker to the cp node.

• on the controlplane node, create a command to use on the worker node: kubeadm token create --print-join-command
• copy the output - this is a "join" command that can be run on the worker node
• run that on the worker node: sudo kubeadm join ...(the rest of the command)