Kubernetes

• System for running many different containers over multiple different machines.
• When you need to run many different containers with different images.

Working with Kubernetes

• Development
  • minikube
    • Minikube is a commond line tool which sole purpose is going to be to set up a tiny little kubernetes cluster(with master and different load balancing nodes)(inside a node there can be mutliple containers)
• Production
  • Managed Solutions
    • Amazon Elastic Container Service for Kubernetes (EKS)
    • Google Cloud Kubernetes Engine (GKE)
  • Do it yourself

Minikube

• Minikube will create a kubernetes cluster in your local machine. Behind the scene, it is going to create a Virtual Machine whose sole purpose is to run certain number of containers.
• We will make only use of minikube in the local environment.

Kubectl

• We will use kubectl to interact with virtual machine created by minikube.
• kubectl is a program that is used to interact with the kubernetes cluster in general and manage what different nodes are doing and what different containers are they running.

Note: When we installed a Docker for Mac or Windows, it was technically creating a virtual machine at the same time. That's essentially, same thing that's happening in the world of kubernetes, the only difference is Docker for Mac or Windows installed the virtual machine for you and all the associated software with it. But in the world of kubernetes not quite so automatic.

Local Kubernetes Development (step-by-step process)

• Install Kubectl -> CLI for interacting with our master
• Install a VM driver vitualbox -> Used to make a VM that will be your single node
• Install minikube -> Runs a single node on that VM

Install minikube and kubectl

• run cmd as admin in windows and then close it and reopen it to run following commad: @"%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -InputFormat None -ExecutionPolicy Bypass -Command "iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'))" && SET "PATH=%PATH%;%ALLUSERSPROFILE%\chocolatey\bin"
• choco install minikube kubernetes-cli -->run as admin in cmd in windows
• for installing on other machine : https://kubernetes.io/docs/tasks/tools/install-minikube/
• choco install kubernetes-cli
• minikube status
• kubectl version
• kubectl cluster-info

We can get multi-client image running on our local Kubernetes Cluster running as a container

Docker Compose and Kubernetes

1. Docker Compose -> Each entry can optionally get docker- compose to build an image a. Kubernetes -> Kubernetes expects all images to already be built --> Make sure our image is hosted on docker hub
2. Docker Compose -> Each entry represents a container we want to create. b. Kubernetes -> One config file per object we want to create --> Make one config file to create the container
3. Docker Compose -> Each entry defines the networking requirements(ports) c. Kubernetes -> We have to manually set up all networking --> Make one config file to set up networking