Cloud Native with Spring Boot and Kubernetes (J4K 2021)

Source code of the examples shown at the conference.

Demonstration of:

• Cloud native development with Spring Boot and Reactive Spring
• Containerization with Cloud Native Buildpacks
• Kubernetes deployment manifests, graceful shutdown, and health probes
• Spring Boot configuration through ConfigMaps
• Native executables with Spring Native and GraalVM
• Serverless applications on Knative

Prerequisites

To run all the examples, you need to install the following tools:

• Java 17
• Docker
• Kubernetes CLI
• kind

Recommended tools:

• Octant
• Knative CLI

Usage

Both Spring Boot applications can be run locally with this command:

$ ./gradlew bootRun

You can containerize them via Buildpacks. Demo Service will be containerized as a JVM image, whereas Demo Native will be containerized as a Native image.

$ ./gradlew bootBuildImage

Deployment on a local Kubernetes cluster

You can spin up a Kubernetes cluster as follows:

$ ./kind/create-cluster.sh

Then, deploy Demo Service with kubectl:

$ kubectl apply demo-service/k8s

When you're done, you can destroy the cluster as follows:

$ ./kind/destroy-cluster.sh

Deployment on a local Kubernetes cluster with Knative

You can spin up a Kubernetes cluster with Knative as follows:

$ ./kind/install-knative.sh

Then, deploy Demo Native with kubectl:

$ kubectl apply demo-service/knative

When you're done, you can uninstall the cluster as follows:

$ ./kind/uninstall-knative.sh

Other

If you're looking for an open-source Kubernetes-based platform, you might want to try [https://tanzucommunityedition.io](VMware Tanzu Community Edition), which is the one I used for the presentation.