DemoConfiguration.md

Demo: Configuration

In order to demonstrate MicroProfile Config, the 'articles' service uses a configuration to define whether or not to create ten articles the first time it is invoked.

In the yaml file an environment variable pointing to a ConfigMap is defined.

kind: Deployment
apiVersion: apps/v1beta1
metadata:
  name: articles
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: articles
        version: v1
    spec:
      containers:
      - name: articles
        image: articles:1
        ports:
        - containerPort: 8080
        env:
        - name: samplescreation
          valueFrom:
            configMapKeyRef:
              name: articles-config
              key: samplescreation
      restartPolicy: Always
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: articles-config
data:
  samplescreation: "true"

In the Java code the configuration can be accessed via @Inject and @ConfigProperty.

public class CoreService {
  @Inject
  @ConfigProperty(name = "samplescreation", defaultValue = "false")
  private boolean samplescreation;
  @PostConstruct
  private void addArticles() {
    if (samplescreation)
      addSampleArticles();
    }

Invoke the following commands to set up the demo. Skip the commands you've already executed.

$ cd $PROJECT_HOME
$ scripts/check-prerequisites.sh
$ scripts/delete-all.sh
$ scripts/deploy-articles-java-jee.sh
$ scripts/show-urls.sh

Invoke the curl command which is displayed as output of 'scripts/show-urls.sh' to get ten articles.

Check out the article Configuring Microservices with MicroProfile and Kubernetes for more details.