Beyond Block Diagrams: Different Ways of Understanding K8s Architecture

Most introductory Kubernetes videos and blog posts use static block diagrams to illustrate the core components of Kubernetes and how they interact. These diagrams don’t convey the dynamic communication between the K8s control plane, nodes, and pods, and we owe it to ourselves and people new to the field more accurate and engaging ways of representing Kubernetes architecture. This talk will demonstrate a few different methods to visualize how Kubernetes components work together including a time-sequence diagram that models what happens when a user creates a pod using the Kubernetes command line tool, kubectl, and how to use Jaeger to see an http request move onto different nodes by traveling through a load balancer, to a service, and arriving at a specific pod. This talk is for people who are new to Kubernetes and want to understand how the system is designed, as well as experienced engineers who are curious about alternative ways of visualizing Kubernetes architecture.

Transcript

2. Kim Schlesinger, DigitalOcean Beyond Block Diagrams: Different Ways of Understanding K8s Architecture
3. Hi, I’m Kim Developer Advocate Site Reliability Engineer JavaScript Developer Elementary School Teacher 2018 @kimschles Beyond Block Diagrams
4. Cloud Native Generation Photo source: https://unsplash.com/photos/8iZG31eXkks @kimschles Beyond Block Diagrams
5. “Any framework that you can hold as a mental representation of an external reality.” - What is a mental model? by Julia Clavien Mental Models Photo source: https://unsplash.com/photos/3KGF9R_0oHs @kimschles Beyond Block Diagrams
6. From the Kubernetes Documentation, Kubernetes Components: https://kubernetes.io/docs/concepts/overview/components/ @kimschles Beyond Block Diagrams
7. Hire, train and retain early-career engineers with limited computing experience Why? @kimschles Beyond Block Diagrams
8. Takeaways 1. Create diagrams that show the passage of time 2. Use distributed tracing technology as a learning tool 3. Build 3D models of Kubernetes clusters Photo source: https://unsplash.com/photos/_gEKtyIbRSM @kimschles Beyond Block Diagrams
9. Agenda 1. Time Sequence Diagram 2. Distributed Traces + Diagram 3. 3D Model @kimschles Beyond Block Diagrams
10. Agenda 1. Time Sequence Diagram 2. Distributed Traces + Diagram 3. 3D Model @kimschles Beyond Block Diagrams
11. Example Time Sequence Diagram | Distributed Tracing + Diagram | 3D Model @kimschles Beyond Block Diagrams
12. kubectl create -f pod.yaml Time Sequence Diagram | Distributed Tracing + Diagram | 3D Model @kimschles Beyond Block Diagrams
13. Time Sequence Diagram @kimschles Beyond Block Diagrams
14. Agenda 1. Time Sequence Diagram 2. Distributed Traces + Diagram 3. 3D Model @kimschles Beyond Block Diagrams
15. Agenda 1. Time Sequence Diagram 2. Distributed Traces + Diagram 3. 3D Model @kimschles Beyond Block Diagrams
16. Distributed Tracing “Distributed tracing, also called distributed request tracing, is a method used to profile and monitor applications, especially those built using a microservices architecture.” - OpenTracing Project Time Sequence Diagram | Distributed Tracing + Diagram | 3D Model @kimschles Beyond Block Diagrams
17. Meow-Micro 🐈 • 2 go microservices • The meow-client accepts requests via a REST API and uses GRPC to communicate with the meow-server • Fernando Diaz at GitLab Example Time Sequence Diagram | Distributed Tracing + Diagram | 3D Model @kimschles Beyond Block Diagrams
18. curl http://143.244.209.228/meow -X POST -d '{"name": "Meow-Mixer"}' Time Sequence Diagram | Distributed Tracing + Diagram | 3D Model @kimschles Beyond Block Diagrams
19. @kimschles Beyond Block Diagrams From Setting up Distributed Tracing with OpenTelemetry & Jaeger in Kubernetes Ingress-NGINX by Fernando Diaz Time Sequence Diagram | Distributed Tracing + Diagram | 3D Model
20. Time Sequence Diagram | Distributed Tracing + Diagram | 3D Model @kimschles From Setting up Distributed Tracing with OpenTelemetry & Jaeger in Kubernetes Ingress-NGINX by Fernando Diaz Beyond Block Diagrams
21. @kimschles Beyond Block Diagrams Time Sequence Diagram | Distributed Tracing + Diagram | 3D Model
22. @kimschles Beyond Block Diagrams Weaveworks kspan Example: rollout of a Deployment of two Pods From weaveworks-experiments/kspan: Turning Kubernetes Events into spans
23. Agenda 1. Time Sequence Diagram 2. Distributed Traces + Diagram 3. 3D Model @kimschles Beyond Block Diagrams
24. Agenda 1. Time Sequence Diagram 2. Distributed Traces + Diagram 3. 3D Model @kimschles Beyond Block Diagrams
25. Example Time Sequence Diagram | Distributed Tracing + Diagram | 3D Model @kimschles Beyond Block Diagrams
26. kubectl create -f pod.yaml Time Sequence Diagram | Distributed Tracing + Diagram | 3D Model @kimschles Beyond Block Diagrams
27. Time Sequence Diagram | Distributed Tracing + Diagram | 3D Model @kimschles Beyond Block Diagrams
28. Agenda 1. Time Sequence Diagram 2. Distributed Traces + Diagram 3. 3D Model @kimschles Beyond Block Diagrams
29. @kimschles Beyond Block Diagrams Recap
30. “Any framework that you can hold as a mental representation of an external reality.” - What is a mental model? by Julia Clavien Mental Models Photo source: https://unsplash.com/photos/3KGF9R_0oHs @kimschles Beyond Block Diagrams
31. Cloud Native Generation Photo source: https://unsplash.com/photos/8iZG31eXkks @kimschles Beyond Block Diagrams
32. From the Kubernetes Documentation, Kubernetes Components: https://kubernetes.io/docs/concepts/overview/components/ @kimschles Beyond Block Diagrams
33. Takeaways 1. Create diagrams that show the passage of time 2. Use distributed tracing technology as a learning tool 3. Build 3D models of Kubernetes clusters Photo source: https://unsplash.com/photos/_gEKtyIbRSM @kimschles Beyond Block Diagrams
34. Hire, train and retain early-career engineers with limited computing experience Why? @kimschles Beyond Block Diagrams
35. Resources Examples of Kubernetes Time Sequence Diagrams • Writing custom Kubernetes Scheduler - My Fake Tardis • A Sequential Breakdown of the Kubernetes Deployment Process- ContainerLabs Time Sequence Diagram Generator • SequenceDiagram.org - UML Sequence Diagram Online Tool @kimschles Beyond Block Diagrams
36. Resources Distributed Tracing with Jaeger and ingress-nginx • Jaeger: open source, end-to-end distributed tracing • OpenTracing - NGINX Ingress Controller Tutorial • Setting up Distributed Tracing in Kubernetes with OpenTracing, Jaeger, and Ingress-NGINX by Fernando Diaz, @awkwardferny Diagram Tool • LucidChart @kimschles Beyond Block Diagrams
37. Resources kspan • Traces from Events: A New Way to Visualise Kubernetes Activities - Bryan Boreham • weaveworks-experiments/kspan: Turning Kubernetes Events into spans @kimschles Beyond Block Diagrams
38. @kimschles