Kubernetes Demystified

Transcript

1. “WHEN YOU LOOK INTO IT, KUBERNETES ISN’T THAT COMPLICATED AFTER

   ALL” WYLIIKITCAA

2. WHAT IS KUBERNETES? CLUSTER STATE STORE (AND MANAGER)

3. WHAT IS KUBERNETES? DESIRED STATE CLUSTER

4. WHAT IS KUBERNETES? “I NEED A CONTAINER RUNNING NGINX” Pick

   feasible nodes Update their desired state Get the current state

5. WHAT IS KUBERNETES? “I NEED A CONTAINER RUNNING NGINX” Pick

   feasible nodes Update their desired state Get the current state

6. HOW DO I SET THE DESIRED STATE? apiVersion: v1 kind:

   Pod metadata: name: nginx spec: containers: - name: nginx image: nginx:1.7.9 ports: - containerPort: 80

7. HOW DO I SET THE DESIRED STATE? $ kubectl create

   -f pod-nginx.yaml

8. WHAT IS KUBERNETES? “I NEED A CONTAINER RUNNING NGINX” Pick

   feasible nodes Update their desired state Get the current state

9. HOW DOES KUBERNETES SELECT THE FEASIBLE NODES? CONTROLLERS

10. DEPLOYMENT STATEFUL SET DAEMON SET WORKLOAD CONTROLLERS

11. DEPLOYMENT Declarative updates Rolling back Scaling Creates ReplicaSets WORKLOAD CONTROLLERS

12. STATEFUL SET Guaranteed order and uniqueness Persistant storage Stable, unique

    network identifiers WORKLOAD CONTROLLERS

13. DAEMON SET Running on all nodes WORKLOAD CONTROLLERS

14. LABELS

15. AFFINITY TAINT Node selectors Required/preferred Conditions Eviction TAINT AND AFFINITY

16. WHAT IS KUBERNETES? “I NEED A CONTAINER RUNNING NGINX” Pick

    feasible nodes Update their desired state Get the current state

17. THE DESIRED STATE

18. ETCD Distributed key/value store Like a directory tree (/etc) JSON/REST

    API Uses a Discovery URL Needs at least 3 nodes for consensus

19. WHAT IS KUBERNETES? “I NEED A CONTAINER RUNNING NGINX” Pick

    feasible nodes Update their desired state Get the current state

20. KUBELET

21. None

22. WHAT IS KUBERNETES? “I NEED A CONTAINER RUNNING NGINX” Pick

    feasible nodes Update their desired state Get the current state
23. None