Add network policy example

Author: ondrejsika

README.md

@@ -1742,6 +1742,48 @@ Resources:
 - https://rancher.com/blog/2019/2019-03-21-comparing-kubernetes-cni-providers-flannel-calico-canal-and-weave/
 - https://info.rancher.com/kubernetes-networking-deep-dive
 
+## Network Policy
+
+Deploy webservers:
+
+```
+kubectl apply -f webservers.yml
+```
+
+Check connection:
+
+```
+kubectl run busybox --rm -ti --image=busybox -- wget --spider --timeout=1 nginx
+```
+
+Apply policy
+
+```
+kubectl apply -f networkpolicy.yml
+```
+
+See policy:
+
+```
+kubectl get networkpolicies
+```
+
+```
+kubectl describe -f networkpolicy.yml
+```
+
+Check connection again:
+
+```
+kubectl run busybox --rm -ti --image=busybox -- wget --spider --timeout=1 nginx
+```
+
+Check connection with labels `--labels="access=true"`:
+
+```
+kubectl run busybox --rm -ti --image=busybox --labels="access=true" -- wget --spider --timeout=1 nginx
+```
+
 ## What's Next? Kubernetes Advance
 
 - Logging (EFK / ELK)

networkpolicy.yml

@@ -0,0 +1,13 @@
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: webservers
+spec:
+  podSelector:
+    matchLabels:
+      project: webservers
+  ingress:
+    - from:
+        - podSelector:
+            matchLabels:
+              access: "true"