This repository contains examples for the talk "Spring Cloud goes Cloud". The main focus of the talk is on running the Spring Boot applications using Docker and Kubernetes.

• config-server - Spring Cloud Config Server
• discovery-service - Service discovery with Eureka
• examinator - entry point, transparently sends requests to subsequent challenge providers
• history - provides challenges about history
• mathematic - provides challenges about math

To request data you need to send POST request to the examinator's /exams/exam endpoint with the following payload:

{
  "MATH": 1,
  "HISTORY": 1
}

Internally, examinator application will request data from math and history providers.

To build the apps you can use Apache Maven because all the apps are using it. However, the build-scripts directory contains a few more scripts which build app differently.

• build-images-naive.sh - this script runs mvn clean package and next uses simple and naive Dockerfile to build Docker images.
• build-images-oci.sh - this script builds Docker images with Spring Boot Maven plugin and buildpacks.
• build-images-layered.sh - this script builds far-jar's and next unpacks them using Spring Boot layered jar. As soon as jar files are unpacked, they are next used to build layered Docker images manually via another Dockerfile.
• build-images-kubernetes.sh - this script builds jar files with with-kubernetes profile active. This profile is important for the math provider - enables reload of configs from ConfigMaps.

Built images can be used to run apps in different ways. See the build-scripts/compose and build-scripts/kubernetes folders.

• compose/naive - running all the images built by build-images-naive.sh script, uses health checks to wait till containers are started.
• compose/oci - runs all the containers based on images built by build-images-oci.sh script. As a result no way to check the health here.
• componse/docker-only - runs all the containers but without service discovery because this functionality is provided by Docker out of the box.
• kubernetes/config-server - a few scripts which run pods and services in Kubernetes.
• kubernetes/config-maps - running apps generated by build-images-kubernetes.sh and so that reloading of ConfigMaps are available.
• kubernetes/autoscaling - the same but with autoscaling based on the CPU usage.

The examinator app exposes liveness and readiness probes as well as a custom PhaseOfTheMoonHealthIndicator. Additionally, mathematics exposes MetricsConfiguration and metrics internally.