k8s

This scripts creates a kubernetes cluster with separated etcd cluster:

------------------------------------------------------------------
 Admin Machine                                     | Host
---|-----------------------------------------------| -------------
 kload1  ......... Load Balancer                   | Guests VM 
   |                                               | - Vagrant
   |----kwork* ... K8s Workers                     | - Multipass
   |----kmast* ... K8s Masters                     |
   |----ketcd* ... Cluster Key-Value Store (etcd)  |
------------------------------------------------------------------

Pre-Requisites

This scripts where tested using the following freaky/nested setup:

• HP Pavilion Gaming Laptop (i9300H 32 GB RAM Windows 10)
  • VMWare Workstation 15 (Enable Intel VT-x/EPT or AMD-V/RVI, CPU Perf. Counters, IOMMU)
    • Ubuntu Linux 18.04 (4 vCPU 16 GB RAM)
      • Virtualbox 6.1 w/Oracle Extension Pack + Vagrant or just only Multipass
        • Ubuntu Linux 18.04 (Virtual Machines for Kuberentes Cluster)

But of course, it should work on any Ubuntu Linux with the following packages installed:

• OPTION #1: VirtualBox + Vagrant
• OPTION #2: Multipass

Virtual Machine Layout

Nodes will be created with the following hostnames according to the numbers defined in environment.sh:

---------------------------------------------------------
 Name   | Quantity                | Capacity             
---------------------------------------------------------
 kload* | 1 <= LOADBALANCERS <= 9 | 2 vCPU +  512 MB RAM
 ketcd* | 2 <= ETCDS <= 9         | 2 vCPU +  798 MB RAM
 kmast* | 1 <= MASTERS <= 9       | 2 vCPU + 1536 MB RAM
 kwork* | 1 <= WORKERS <= 9       | 2 vCPU + 1024 MB RAM
---------------------------------------------------------
                                  | 8 vCPU + 7740 MB RAM
---------------------------------------------------------

Additional Notes

Maximum 9 servers are meant to be created per type, if more needed you need to modify networks in 000_all_hosts.sh.

You can modify the CPU and RAM values in Vagrantfile and setup.sh (multipass) file but the minimums are already set there as described before.

If you use several kload* you should modify the 080_master_init.sh accordingly before running setup.sh. For example, adding more etcd endpoints (e.g. kload2).

Defining "controlPlaneEndpoint:" as kload is not possible, even if resolved from kload1 and kload2 via DNS, authentication will fail due to certificates not provisioned for kload hostname (at least with this scripts).

Pod network CIDR (Subnet) is defined in the 080_master_init.sh, you can change it to fit your needs.

Create Cluster

Prepare Scripts

Clone the repo and setup the permissions:

git clone git@github.com:olafrv/k8s.git
cd k8s
chmod +x *.sh

Edit environment.sh global variables.

source environment.sh

Setup Virtual Machines (Multipass) - RECOMMENDED (LIGHTER)

./setup.sh multipass

Setup Virtual Machines (Vagrant) - ALTERNATIVE (HEAVIER)

./setup.sh vagrant

If you need to run again setup, you can revert every virtual machine to their initial state:

vagrant snapshot list
vagrant snapshot restore <vm> before-setup

Output

If everything goes well:

You can use kubectl from you admin machine.

kubectl get nodes

In the ./secrets/init.txt will be the output of kubeadm init command.

In the server kmast1:~/join-command-for-worker will have the command to join worker nodes.

K8s Tools (Admin Machine)

The setup.sh already download the kubeconfig, but you can rerun it as needed:

bash 090_local_download_kube_config.sh

If you want to install the kubernetes dashboard:

bash 200_local_dashboard.sh   # See more information in this script on how to use it

If you want to install more k8s command lines tools:

bash 300_local_user_tools.sh  # You can do it manually selection the tools you like

It is highly recommended for GUI to try https://k8slens.dev/ in your admin machine, it can deploy metrics server and prometheus for you.

References

NNN_.sh* called from setup.sh includes all the references use for creating the k8s cluster.