Why do we use container port in Kubernetes?

Question

Docker

Good afternoon,

such a stupid question arose, in the yaml code for pods we can specify the ports directive, for example:

spec:
      containers:
      - name: my-nginx
        image: nginx
        ports:
        - containerPort: 80
          name: nginx-port

The question is why do we actually need this, because the pod still has access to the container's network space? And pod works fine on port 80 and without this directive

, all the best,
Vadim

Answer 1

in fact, the following yaml just shows that ports: has some informational value, because everything works on the 80th

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-nginx
spec:
  selector:
    matchLabels:
      run: my-nginx
  replicas: 2
  template:
    metadata:
      labels:
        run: my-nginx
    spec:
      containers:
      - name: my-nginx
        image: nginx
        ports:
        - containerPort: 8090
          name: nginx-fake-port