This document provides an overview of Kubernetes for Java developers. It discusses setting up Kubernetes with Docker and Minikube to deploy Java microservices. It covers key Kubernetes concepts like pods, replica sets, services and ingress. It also provides steps to deploy a sample database and application on Kubernetes, and best practices for containerizing Java applications to run on Kubernetes.

1. Kubernetes for Java Developers
@sandrogiacom

2. Kubernetes for Java Developers
The ​​technology area is cyclical, from time to time the
same technologies come back, with different names.
(Heidemann, Vanei)
Series available at https://dev.to/sandrogiacom/kubernetes-for-java-
developers-setup-41nk

3. I’m here
I'm working with Java micro-services that integrate and
depend on many other services.
The microservices are packaged in docker containers and
run in a kubernetes cluster.

4. Kubernetes?
Kubernetes is a portable, extensible open-source
platform for managing containerized workloads and
services, that facilitates both declarative configuration
and automation. It has a large, rapidly growing
ecosystem. Kubernetes services, support, and tools are
widely available.
https://kubernetes.io/docs/concepts/overview/what-is-kubernetes/

5. Setup
● Docker
● Minikube
● Kubectl
● VirtualBox
● GNU make (recommended)
https://github.com/sandrogiacom/k8s

6. Before run
Clone demo app
https://github.com/sandrogiacom/java-kubernetes

7. Step one - Standalone App

8. Step two - Docker App

9. Step three - App on Kubernetes

10. Local Running
Minikube
Docker
Kubectl

11. Start Minikube
minikube -p dev.to start --cpus 2 --memory=4098

13. And?
K8s (K - ubernete - s)
Deployment
● Pods
● Replica Sets
Services
Ingress

14. Deploy Database and Application

15. Ingress
Application with friendly access

16. Deploy Database
kubectl apply -f kubernetes/mysql/

17. Build docker image local
eval $(minikube -p dev.to docker-env)
docker build --force-rm -t java-k8s .

18. Deploy App
kubectl apply -f kubernetes/app/

19. Debug
Prepare docker and kubernetes to allow
debugging

20. Good practices
● Use JRE images, not JDK
● Automate everything possible
● Use Environment variables
● Health Check
● Application info
● Monitoring / Logs

22. https://developers.redhat.com/books/microservices-java-developers-hands-introduction-frameworks-and-containers/old/

23. https://www.nginx.com/resources/library/docker-for-java-developers/

24. https://www.nginx.com/resources/library/kubernetes-for-java-developers/

25. http://www.javamagazine.mozaicreader.com/MayJune2019#&pageSet=0&page=0