Add OS and OpenShift questions

certificates/cka.md

@@ -1,7 +1,15 @@
 ## Certified Kubernetes Administrator (CKA)
 
+### Pods
+
 <details>
 <summary>Deploy a pod called web-1985 using the nginx:alpine image</code></summary><br><b>
 
 `kubectl run web-1985 --image=nginx:alpine --restart=Never`
 </b></details>
+
+<details>
+<summary>How to find out on which node a certain pod is running?</summary><br><b>
+
+`kubectl get po -o wide`
+</b></details>