rhuss / fmp-demo-random-generator

Demo for fabric8-maven-plugin using spring boot

Zero-Config

• Create Spring-Boot starter at https://start.spring.io/
  • meetup
  • random-generator
  • actuator, web, devtools
• Create mapping in the main application class
  • Set version to non-snapshot version
  • @RestController
  • @RequestMapping(value = "/", produces = "application/json")
  • Add a UUID id
  • Return a map with "random" and "id"
  • (Best: Create Live Templates for IDEA for the various parts)
• Run locally
  • mvn spring-boot:run
• Check with IDEA console
• Open in browser
  • open http://localhost:8080/
• Show devtools by changing code
• Add f-m-p dependency (3.5.31)
• Set project version to non-snapshot version to avoid problems with the timestamped versioning of images for snapshots
• Start minikube
  • minikube start
  • minikube addons enable heapster
  • eval $(minikube docker-env)
• Build docker image
  • mvn package fabric8:build
• Show create Docker image
  • docker images
• Run with docker
  • docker run -it -p 8181:8080 demo/random-generator:1.0.0
  • open http://$(minikube ip):8181/
• Create deployment descriptors
  • mvn fabric8:resource
  • Show resources in target/class/META-INF/fabric8
  • Maybe try also with mvn fabric8:resource -Dfabric8.profile=minimal
• Apply them to Kubernetes
  • mvn fabric8:apply
• Show objects
  • with kubectl
  • minikube dashboard
• Edit pom.xml, add

<properties>
  <fabric8.enricher.fmp-service.type>NodePort</fabric8.enricher.fmp-service.type>
</properties>

<enricher>
  <config>
    <fmp-service>
      <type>NodePort<type>
    </fmp-service>
  </config>
</enricher>

• Edit service type to NodePort
  • kubectl patch svc random-generator -p '{"spec":{"type":"NodePort"}}'
  • kubectl describe svc random-generator
  • open $(minikube service --url random-generator)
  • curl -s $(minikube service --url random-generator) | jq .

Debug

• Run
  • mvn fabric8:debug
• Connect via IDE
• Set breakpoint in handler
• Change object on the fly

Watch

• Check that execution mappings are set in the pom.xml:

<executions>
  <execution>
    <goals>
      <goal>resource</goal>
      <goal>build</goal>
    </goals>
  </execution>
</executions>

• Check that secret is set in application.properties:

spring.devtools.remote.secret=3b9c37f9-6777-4c9c-bc76-8f790752f7a6

• Start watch
  • mvn fabric8:undeploy fabric8:watch
  • Be sure the goals are bound to executions
  • Don't forget the undeploy step !! (for now, should be fixed of course)
  • Show also live reload in browser (Disable everything running on port 8080 for this to work e.g. the presentation itself)
• Rescale:
  • kubectl scale deployment random-generator --replicas=3

 watch "curl -s $(minikube service --url random-generator)/ | jq ."

Client

• New Java project
• Dependency: json-simple
• Configuration: Exclude enricher "fmp-service"
• Class jax2017.Client
  • UUID
  • main with
    • Endless thread and Thread.sleep 1000
    • URL to service (by name)
    • JSONObject response via JSONParser and InputStreamReader on url
    • output response to "/random-data/responses.txt"
    • new FileWriter with append == true
    • response.writeJSONString(out)
• pom.xml: add maven exec plugin

Fragments:

• pv001-pv.yml

spec:
  accessModes:
    - ReadWriteOnce
  capacity:
    storage: 20M
  hostPath:
    path: /data/pv001/

• random-client-deployment.yml

spec:
  replicas: 3
  template:
    spec:
      containers:
        - name: java-exec
          volumeMounts:
          - mountPath: "/random-data"
            name: random-data
      volumes:
        - name: random-data
          persistentVolumeClaim:
            claimName: random-data

• random-data-pvc.yml

spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10M

• Add a volume

Snippets

open http://$(minikube ip):$(kubectl get svc random-generator -o jsonpath='{.spec.ports[*].nodePort}')/random