Why Kubernetes?

Containers, by nature, are scalable. However, the task to manage running containers is difficult, and there is no point to scale if we cannot manage them.

• Containers cannot communicate with each other
• Containers have to be deployed properly
• Containers have to be managed
• Auto scaling is not possible
• Distributing traffic between containers

What is Kubernetes?

A platform to automate deploying, scaling, and operating containers

Basic terminologies

Cluster

• A group of virtual machines/physical computers that run containerized applications
• A Kubernetes cluster is a cluster being orchestrated by Kubernetes

Kubernetes Objects

• Kubernetes objects are persistent entities in the Kubernetes system. Kubernetes uses these entities to represent the state of your cluster.
• Almost every Kubernetes object includes two nested object fields that govern the object’s configuration: the object spec and the object status.
  • spec - (not every object has this) you have to set this when you create the object, providing a description of the characteristics you want the resource to have: its desired state
  • status - the current state of the object, supplied and updated by the Kubernetes system and its components. The control plane continually and actively manages every object’s actual state to match the desired state you supplied.

Namespaces

Think of namespaces like projects and namespaces in a .NET solution. It is used to group resources and objects per some criteria and isolate those objects from others outside the namespace.

Nodes

• A virtual machine/physical computer that serves as a worker machine in a cluster