Deployments in Kubernetes

Why Do We Even Need Deployments?

You already know:

A Pod runs containers.

But here’s the problem:

• Pods are ephemeral
• If a Pod crashes → it dies
• If a node dies → the Pod is gone
• If you delete it → it’s gone
• If you want multiple replicas → you manually create multiple Pods (bad idea)

So Kubernetes introduces controllers.

A controller’s job is:

“Continuously ensure the cluster matches the desired state.”

And Deployment is one of those controllers.

Big Picture Architecture

Deployment
    ↓
ReplicaSet
    ↓
   Pods
    ↓
Containers

You don’t directly manage ReplicaSets, Deployment does that for you.