Commandeering Kubernetes with Elixir

The basics of extending Kubernetes using the Operator Pattern and a demo of using Bonny, the Elixir based Kubernetes Development Framework.

Transcript

1. Commandeering Kubernetes with Elixir
2. Cory O’Daniel (apostrophe not required) Senior YAML Architect @ Container Heroes Creator of Bonny Kubernetes Development Framework @coryodaniel @coryodaniel
4. Why do we extend? The operator pattern allows you to codify the expertise of a human operator with deep knowledge of managing an application or set of services and how to react if there are problems.
5. Why do we extend? Declarative Highly Available Databases
6. Why do we extend?
7. Why do we extend? On-demand database snapshots
8. Why do we extend?
9. Why do we extend? Generating TLS Certificates
10. Why do we extend?
11. Why do we extend? Creating S3 Buckets
12. Why do we extend?
13. The Operator pattern for extending Kubernetes • Process a chunked HTTP stream of add, modify, and delete events • Continually reconcile k8s resources’ state changes • Manage background tasks, processes, and state
15. Why Kubernetes? Service Discovery and Load Balancing NODE NODE Where is microservice-a.prod.svc.cluster.local NODE MASTERS
16. Why Kubernetes? Scaling NODE NODE NODE NODE
17. Why Kubernetes? Storage Orchestration NODE NODE NODE SSD NFS Host Path
18. Why Kubernetes? Automated rollouts / rollbacks v1 NODE v1 NODE v1 NODE v2 v2 v2
19. Why Kubernetes? Automated bin packing
20. Why Kubernetes? Self-healing NODE NODE NODE
21. Why Kubernetes? • Secret and Config Management • Single deployment tool/interface • Portability
22. Kubernetes Crash Course
25. Resource Attributes And Metadata
26. Metadata as REST Path
27. `kubectl explain pod` • 1 or more colocated docker containers • Acts as a “logical host” • Share volumes • Share network • Live and die as a unit
28. `kubectl explain deployment` • Declarative management of pods ◦ Desired number of pod replicas ◦ Rollout Strategy ◦ Revision History
29. `kubectl explain service` • Exposes a set of pods as a network service • Selects pods using labels
30. Life of a Deployment
31. Scheduler ETCD Master Components NODES Deployment ReplicaSet Pod API Server Deployment Controller ReplicaSet Controller Ctrl Manager HTTP POST HTTP GET deployment/nginx replicaset/nginx-jk1234 pod/nginx-jk1234-6963
32. Node Components MASTERS kubelet docker TCP 8888 TCP 4269
33. Writing a Kubernetes Operator
34. Our first operator: Todos App Create a Custom Resource Definition (CRD) • Generates a REST Endpoint • Defines the fields and validations we expect
35. Our first operator: Todos App Create a Controller • Polls REST endpoint • Reconciles changes in resource state
36. Todo CRD: YAML Warning
40. Todo Resource
41. Interacting with your Custom Resource
46. Creating a Controller
51. Building and Deploying an Operator
60. Creating and Deleting Todos
64. Where do we go from here?
65. Applications are long running, side-effect filled functions with env vars, flags, and config files as arguments.
69. Thanks!