Zero downtime deployments of .NET Core apps on GKE

In this presentation I'm documenting the learnings along the way of achieving zero down time deployments of .NET Core apps on GKE. This talk briefly talks about liveness & readiness probes, pod lifecycle and service networking and how these affect a deployment.

Transcript

1. Zero downtime deployment of .NET Core Web API on GKE Vignesh
2. About me • Head of R&D & TitansoF • Overall system architecture • InnovaJon • Interests • Distributed System, FP • ⚽,
3. Zero downtime deployment of .NET Core Web API on GKE
4. Titansoft Tech Stack
5. Problems tackled 1. Zero down time deployments 2. Infrastructure abstraction for devs 3. Application abstraction for ops
6. Titansoft Tech Stack - 202\d
7. Architecture
8. “Rolling updates allow Deployments' update to take place with zero downtime by incrementally updating Pods instances with new ones.” https://kubernetes.io/docs/tutorials/kubernetes-basics/update/update-intro/
10. AUempt #1
11. Pod Lifecycle Pending The Pod has been accepted by the Kubernetes system, but one or more of the Container images has not been created. This includes time before being scheduled as well as time spent downloading images over the network, which could take a while. Running The Pod has been bound to a node, and all the Containers have been created. At least one Container is still running or is in the process of starting or restarting. Succeeded All Containers in the Pod have terminated in success and will not be restarted. Failed All Containers in the Pod have terminated, and at least one Container has terminated in failure. That is, the Container either exited with non-zero status or was terminated by the system. Unknown For some reason, the state of the Pod could not be obtained, typically due to an error in communicating with the host of the Pod. https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle/
12. Pod Lifecycle Running The Pod has been bound to a node, and all the Containers have been created. At least one Container is still running or is in the process of starting or restarting.
13. Liveness & Readiness Probes https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-probes/
14. Adding readiness probes
15. Termination of pods
16. hGps://kubernetes.io/docs/concepts/workloads/pods/pod/#terminaIon-of-pods
17. Service Networking
18. https://blog.markvincze.com/graceful-termination-in-kubernetes-with-asp-net-core/
19. Pre stop hooks
21. iptables
22. keep-alive: false
23. GCP HTTP(s) Load Balancer as Ingress
24. Container Native Load Balancing
25. Use NEG
26. Summary 1. Readiness probe 2. Pod pre-stop lifecycle hook 3. NEG
28. Since then…