[Mock3_5] Network policy

docs >> https://kubernetes.io/ko/docs/concepts/services-networking/network-policies/

We have deployed a new pod called np-test-1 and a service called np-test-service. Incoming connections to this service are not working.

Troubleshoot and fix it.Create NetworkPolicy, by the name ingress-to-nptest that allows incoming connections to the service over port 80.

Important: Don't delete any current objects deployed.

Important: Don't Alter Existing Objects!

NetworkPolicy: Applied to All sources (Incoming traffic from all pods)?

NetWorkPolicy: Correct Port?

NetWorkPolicy: Applied to correct Pod?

template
---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: test-network-policy
  namespace: default
spec:
  podSelector:
    matchLabels:
      role: db
  policyTypes:
    - Ingress
    - Egress
  ingress:
    - from:
        - ipBlock:
            cidr: 172.17.0.0/16
            except:
              - 172.17.1.0/24
        - namespaceSelector:
            matchLabels:
              project: myproject
        - podSelector:
            matchLabels:
              role: frontend
      ports:
        - protocol: TCP
          port: 6379
  egress:
    - to:
        - ipBlock:
            cidr: 10.0.0.0/24
      ports:
        - protocol: TCP
          port: 5978


---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: ingress-to-nptest
  namespace: default
spec:
  podSelector:
    matchLabels:
      run: np-test-1
  policyTypes:
  - Ingress
  ingress:
  - ports:
    - protocol: TCP
      port: 80

spec: 네트워크폴리시 사양에는 지정된 네임스페이스에서 특정 네트워크 정책을 정의하는데 필요한 모든 정보가 있다.

podSelector: 각 네트워크폴리시에는 정책이 적용되는 파드 그룹을 선택하는 podSelector 가 포함된다. 예시 정책은 "run=np-test-1" 레이블이 있는 파드를 선택한다. 비어있는 podSelector 는 네임스페이스의 모든 파드를 선택한다.

spec.podSelector을 꼭 넣어주도록하자....
당연한게

---

다른 문제

Create a new NetworkPolicy named allow-port-from-namespace in the exiting namespace devops.

Ensure that the new NetworkPolicy allow pods in namespace migops to connect to port 80 of Pods in namespace devops.

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-port-from-namespace
  namespace: devops
spec:
  podSelector: {}
  policyTypes:
    - Ingress
  ingress:
    - from:
        - namespaceSelector:
            matchLabels:
              project: migops
      ports:
        - protocol: TCP
          port: 80