© 2019, Amazon Web Services, Inc. or its affiliates. All rights reserved. Building a Kubernetes Operator in Quarkus D E M 3 5 - S Fabian Lange VP of Engineering Instana 

What is … • Kubernetes? • Container orchestration system • An Operator? • Kubernetes software extension to manage applications and its components • Quarkus? • Java Framework designed for Kubernetes 

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Getting Started mvn \ io.quarkus:quarkus-maven-plugin:0.19.1:create \ -DprojectGroupId=com.instana \ -DprojectArtifactId=operator-example \ -DclassName="com.instana.operator.HelloResource" \ -Dpath="/hello" mvn \ quarkus:add-extension \ -Dextensions=quarkus-kubernetes-client 

package com.instana.operator; public class ClientProducer { @Produces @Singleton KubernetesClient makeDefaultK8sClient(@Named("namespace") String namespace) { return new DefaultKubernetesClient().inNamespace(namespace); } @Produces @Singleton @Named("namespace") String findMyNamespace() throws IOException { return new String(Files.readAllBytes( Paths.get("/var/run/secrets/kubernetes.io/serviceaccount/namespace"))); } } Creating a Kubernetes Client 

package com.instana.operator; public class PodLister { @Inject KubernetesClient defaultClient; void onStartup(@Observes StartupEvent e) { defaultClient.pods().list().getItems().stream() .map(PodPrinter::toString) .forEach(System.out::println); defaultClient.pods().watch(new Watcher() { public void eventReceived(Action action, Pod pod) { System.out.println(action + " on " + PodPrinter.toString(pod)); } }); } } Listing and Watching Pods 

Building and Running mvn \ clean package -DskipTests && \ docker build -f src/main/docker/Dockerfile.jvm -t instana/demo-operator:1 . && \ kind load docker-image instana/demo-operator:1 kubectl run --image=nginx --restart=Never nginx1 kubectl apply -f operator.yaml kubectl run --image=nginx --restart=Never nginx2 NAME READY STATUS RESTARTS AGE nginx1 1/1 Running 0 23s operator-example-6fb74d98c5-5zzj9 1/1 Running 0 19s nginx2 1/1 Running 0 14s 

Operator Output exec java -Dquarkus.http.host=0.0.0.0 -Djava.util.logging.manager=org.jboss.logmanager.LogManager -javaagent:/opt/agent-bond/agent- bond.jar=jmx_exporter{{9779:/opt/agent-bond/jmx_exporter_config.yml}} -XX:+UseParallelGC -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -XX:MinHeapFreeRatio=20 -XX:MaxHeapFreeRatio=40 -XX:+ExitOnOutOfMemoryError -cp . -jar /deployments/app.jar Pod nginx1 version 3143 Pod operator-example-6989bcf5f8-j4d2d version 3457 2019-10-14 14:35:02,320 INFO [io.quarkus] (main) Quarkus 0.19.1 started in 1.866s. Listening on: http://[::]:8080 2019-10-14 14:35:02,322 INFO [io.quarkus] (main) Installed features: [cdi, kubernetes- client, resteasy] ADDED on Pod nginx2 version 4512 MODIFIED on Pod nginx2 version 4513 MODIFIED on Pod nginx2 version 4514 MODIFIED on Pod nginx2 version 4526