the Deployment
is the
standing order / plan
Chapter 4 · Kubernetes School
Keeping the Right Number Open
In chapter 1, we told the principal: “Always keep three maths classrooms open.”
A standing order
That was not a one-time wish.
It was a standing order.
In Kubernetes, that standing order is called a Deployment.
A Deployment is how you tell the principal:
how many classrooms you want,
and what kind of lesson should run inside them.
So:
the Pod
is the
classroom that makes the plan real
The plan keeps checking
You do not chase every classroom yourself.
You write the plan once.
Then the principal keeps checking.
Desired state: three maths classrooms.
Actual state: how many are open right now?
If one closes, the principal opens another.
If somehow four appear, the principal can close the extra one.
Desired state and actual state
The Deployment is the plan that says “keep three.”
Desired state:
Three maths classrooms.
Actual state:
Three maths classrooms are open right now.
The right number is running.
The pods are the classrooms that make that plan real.
The plan stays
So the principal is not guessing.
The principal is following your plan.
That is why Kubernetes feels calm when things break.
The plan stays.
The classrooms can be replaced.
What matters is that the right number of lessons keep running.