[BAEL-7049] Kubernetes Operator (#15469)

* [BAEL-7049] Article Code

* [BAEL-7049] Fix README

---------

Co-authored-by: Philippe Sevestre <psevestre@gmail.com>

kubernetes-modules/k8s-operator/.gitignore

@@ -0,0 +1,41 @@
+#Maven
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+release.properties
+.flattened-pom.xml
+
+# Eclipse
+.project
+.classpath
+.settings/
+bin/
+
+# IntelliJ
+.idea
+*.ipr
+*.iml
+*.iws
+
+# NetBeans
+nb-configuration.xml
+
+# Visual Studio Code
+.vscode
+.factorypath
+
+# OSX
+.DS_Store
+
+# Vim
+*.swp
+*.swo
+
+# patch
+*.orig
+*.rej
+
+# Local environment
+.env
+

kubernetes-modules/k8s-operator/README.md

@@ -0,0 +1,4 @@
+# Dependency-Track operator
+
+This sample demonstrates how to create a simple operator using the Java Operator Framework. In our case, the operator will facilitate
+the deployment of a Dependency-Track instance on a cluster.

kubernetes-modules/k8s-operator/k8s/deptrack-controller.yaml

@@ -0,0 +1,88 @@
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: deptrack-operator
+
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: deptrack-operator
+  namespace: deptrack-operator
+
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: deptrack-operator
+  namespace: deptrack-operator
+spec:
+  selector:
+    matchLabels:
+      app: deptrack-operator
+  template:
+    metadata:
+      labels:
+        app: deptrack-operator
+    spec:
+      serviceAccountName: deptrack-operator
+      containers:
+        - name: operator
+          image: deptrack-operator
+          imagePullPolicy: IfNotPresent
+          ports:
+            - containerPort: 8080
+          readinessProbe:
+            httpGet:
+              path: /actuator/health/readiness
+              port: 8080
+            initialDelaySeconds: 5
+          livenessProbe:
+            httpGet:
+              path: /actuator/health/liveness
+              port: 8080
+            initialDelaySeconds: 30
+
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: deptrack-operator-admin
+subjects:
+  - kind: ServiceAccount
+    name: deptrack-operator
+    namespace: deptrack-operator
+roleRef:
+  kind: ClusterRole
+  name: deptrack-operator
+  apiGroup: ""
+
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: deptrack-operator
+rules:
+  - apiGroups:
+      - ""
+    resources:
+      - deployments
+      - services
+      - ingresses
+      - configmaps
+      - secrets
+    verbs:
+      - '*'
+  - apiGroups:
+      - "apiextensions.k8s.io"
+    resources:
+      - customresourcedefinitions
+    verbs:
+      - '*'
+  - apiGroups:
+      - "com.baeldung"
+    resources:
+      - deptrackresources
+      - deptrackresources/status
+    verbs:
+      - '*'

kubernetes-modules/k8s-operator/k8s/test-resource.yaml

@@ -0,0 +1,12 @@
+apiVersion: com.baeldung/v1
+kind: DeptrackResource
+metadata:
+  namespace: test
+  name: deptrack1
+  labels:
+    project: tutorials
+  annotations:
+    author: Philippe Sevestre
+
+spec:
+  ingressHostname: deptrack.172.31.42.16.nip.io

kubernetes-modules/k8s-operator/pom.xml

@@ -0,0 +1,111 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-3</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>./../../parent-boot-3</relativePath>
+    </parent>
+
+    <artifactId>k8s-operator</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>k8s-operator</name>
+    <packaging>jar</packaging>
+
+    <properties>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+        <josdk.version>4.6.0</josdk.version>
+        <fabric8-client.version>6.9.2</fabric8-client.version>
+        <bouncycastle.version>1.77</bouncycastle.version>
+        <slf4j.version>2.0.9</slf4j.version>
+        <operator-framework-spring-boot.version>5.4.0</operator-framework-spring-boot.version>
+    </properties>
+
+
+    <dependencies>
+
+        <dependency>
+            <groupId>io.javaoperatorsdk</groupId>
+            <artifactId>operator-framework-spring-boot-starter</artifactId>
+            <version>${operator-framework-spring-boot.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>io.javaoperatorsdk</groupId>
+            <artifactId>operator-framework-spring-boot-starter-test</artifactId>
+            <version>${operator-framework-spring-boot.version}</version>
+            <scope>test</scope>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.apache.logging.log4j</groupId>
+                    <artifactId>log4j-slf4j2-impl</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <optional>true</optional>
+        </dependency>
+
+        <dependency>
+            <groupId>io.fabric8</groupId>
+            <artifactId>crd-generator-apt</artifactId>
+            <version>${fabric8-client.version}</version>
+            <scope>provided</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.bouncycastle</groupId>
+            <artifactId>bcprov-jdk18on</artifactId>
+            <version>${bouncycastle.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.bouncycastle</groupId>
+            <artifactId>bcpkix-jdk18on</artifactId>
+            <version>${bouncycastle.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+    </dependencies>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <configuration>
+                    <image>
+                        <name>deptrack-operator</name>
+                    </image>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/Application.java

@@ -0,0 +1,18 @@
+package com.baeldung.operators.deptrack;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+
+@SpringBootApplication
+public class Application {
+
+    private static final Logger log = LoggerFactory.getLogger(Application.class);
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class,args);
+    }
+
+}

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/config/OperatorConfiguration.java

@@ -0,0 +1,10 @@
+package com.baeldung.operators.deptrack.config;
+
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class OperatorConfiguration {
+
+
+
+}

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/controller/deptrack/DeptrackOperatorReconciler.java

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+package com.baeldung.operators.deptrack.controller.deptrack;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.stereotype.Component;
+
+import com.baeldung.operators.deptrack.resources.deptrack.DeptrackApiServerDeploymentResource;
+import com.baeldung.operators.deptrack.resources.deptrack.DeptrackApiServerServiceResource;
+import com.baeldung.operators.deptrack.resources.deptrack.DeptrackFrontendDeploymentResource;
+import com.baeldung.operators.deptrack.resources.deptrack.DeptrackFrontendServiceResource;
+import com.baeldung.operators.deptrack.resources.deptrack.DeptrackIngressResource;
+import com.baeldung.operators.deptrack.resources.deptrack.DeptrackResource;
+
+import io.javaoperatorsdk.operator.api.reconciler.Context;
+import io.javaoperatorsdk.operator.api.reconciler.ControllerConfiguration;
+import io.javaoperatorsdk.operator.api.reconciler.Reconciler;
+import io.javaoperatorsdk.operator.api.reconciler.UpdateControl;
+import io.javaoperatorsdk.operator.api.reconciler.dependent.Dependent;
+import jakarta.annotation.PostConstruct;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@ControllerConfiguration(dependents = {
+    @Dependent(name = DeptrackApiServerDeploymentResource.COMPONENT, type = DeptrackApiServerDeploymentResource.class),
+    @Dependent(name = DeptrackFrontendDeploymentResource.COMPONENT, type = DeptrackFrontendDeploymentResource.class),
+    @Dependent(name = DeptrackApiServerServiceResource.COMPONENT, type = DeptrackApiServerServiceResource.class),
+    @Dependent(name = DeptrackFrontendServiceResource.COMPONENT, type = DeptrackFrontendServiceResource.class),
+    @Dependent(type = DeptrackIngressResource.class )
+})
+@Slf4j
+@RequiredArgsConstructor
+@Component
+public class DeptrackOperatorReconciler implements Reconciler<DeptrackResource> {
+
+    private final ApplicationContext ctx;
+
+
+    @PostConstruct
+    void onPostConstruct() {
+        log.info("Reconciler created");
+    }
+
+    @Override
+    public UpdateControl<DeptrackResource> reconcile(DeptrackResource resource, Context<DeptrackResource> context) throws Exception {
+        return UpdateControl.noUpdate();
+    }
+}

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/resources/Constants.java

@@ -0,0 +1,9 @@
+package com.baeldung.operators.deptrack.resources;
+
+public interface Constants {
+
+    String OPERATOR_NAME = "dependency-track-demo-operator";
+    String DEFAULT_API_SERVER_IMAGE = "dependencytrack/apiserver";
+    String DEFAULT_FRONTEND_IMAGE = "dependencytrack/frontend";
+
+}

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/resources/deptrack/BuilderHelper.java

@@ -0,0 +1,53 @@
+package com.baeldung.operators.deptrack.resources.deptrack;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.List;
+
+import com.baeldung.operators.deptrack.resources.Constants;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
+
+import io.fabric8.kubernetes.api.model.ManagedFieldsEntry;
+import io.fabric8.kubernetes.api.model.ObjectMetaBuilder;
+import io.fabric8.kubernetes.client.CustomResource;
+
+public final class BuilderHelper {
+    private static ObjectMapper om;
+    static {
+        om = new ObjectMapper(new YAMLFactory());
+    }
+
+    private BuilderHelper(){}
+
+    public static <T extends CustomResource<?,?>> ObjectMetaBuilder fromPrimary(T primary, String component) {
+        return  new ObjectMetaBuilder()
+          .withNamespace(primary.getMetadata().getNamespace())
+          .withManagedFields((List<ManagedFieldsEntry>)null)
+          .addToLabels("component", component)
+          .addToLabels("name", primary.getMetadata().getName())
+          .withName(primary.getMetadata().getName() + "-" + component)
+          .addToLabels("ManagedBy", Constants.OPERATOR_NAME);
+    }
+
+    public static <T> T loadTemplate(Class<T> clazz, String resource) {
+
+        ClassLoader cl = Thread.currentThread().getContextClassLoader();
+        if ( cl == null ) {
+            cl =  BuilderHelper.class.getClassLoader();
+        }
+
+        try (InputStream is = cl.getResourceAsStream(resource)){
+            return loadTemplate(clazz, is);
+        }
+        catch(IOException ioe) {
+            throw new RuntimeException("Unable to load classpath resource '" + resource + "': " + ioe.getMessage());
+        }
+
+
+    }
+
+    public  static <T> T loadTemplate(Class<T> clazz, InputStream is) throws IOException{
+        return om.readValue(is, clazz);
+    }
+}

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/resources/deptrack/DeptrackApiServerDeploymentResource.java

@@ -0,0 +1,102 @@
+package com.baeldung.operators.deptrack.resources.deptrack;
+
+import static com.baeldung.operators.deptrack.resources.deptrack.BuilderHelper.fromPrimary;
+
+import java.util.Map;
+
+import org.springframework.util.StringUtils;
+
+import com.baeldung.operators.deptrack.resources.Constants;
+
+import io.fabric8.kubernetes.api.model.LabelSelector;
+import io.fabric8.kubernetes.api.model.LabelSelectorBuilder;
+import io.fabric8.kubernetes.api.model.ObjectMeta;
+import io.fabric8.kubernetes.api.model.PodSpec;
+import io.fabric8.kubernetes.api.model.PodSpecBuilder;
+import io.fabric8.kubernetes.api.model.PodTemplateSpec;
+import io.fabric8.kubernetes.api.model.PodTemplateSpecBuilder;
+import io.fabric8.kubernetes.api.model.apps.Deployment;
+import io.fabric8.kubernetes.api.model.apps.DeploymentBuilder;
+import io.fabric8.kubernetes.api.model.apps.DeploymentSpec;
+import io.fabric8.kubernetes.api.model.apps.DeploymentSpecBuilder;
+import io.javaoperatorsdk.operator.api.reconciler.Context;
+import io.javaoperatorsdk.operator.api.reconciler.ResourceIDMatcherDiscriminator;
+import io.javaoperatorsdk.operator.processing.dependent.kubernetes.CRUDKubernetesDependentResource;
+import io.javaoperatorsdk.operator.processing.dependent.kubernetes.KubernetesDependent;
+import io.javaoperatorsdk.operator.processing.event.ResourceID;
+
+@KubernetesDependent( resourceDiscriminator = DeptrackApiServerDeploymentResource.Discriminator.class)
+public class DeptrackApiServerDeploymentResource extends CRUDKubernetesDependentResource<Deployment, DeptrackResource> {
+
+    public static final String COMPONENT = "api-server";
+
+    private Deployment template;
+    public DeptrackApiServerDeploymentResource() {
+        super(Deployment.class);
+        this.template = BuilderHelper.loadTemplate(Deployment.class, "templates/api-server-deployment.yaml");
+    }
+
+    @Override
+    protected Deployment desired(DeptrackResource primary, Context<DeptrackResource> context) {
+
+        ObjectMeta meta = fromPrimary(primary,COMPONENT)
+          .build();
+
+        return new DeploymentBuilder(template)
+          .withMetadata(meta)
+          .withSpec(buildSpec(primary, meta))
+          .build();
+    }
+
+    private DeploymentSpec buildSpec(DeptrackResource primary, ObjectMeta primaryMeta) {
+
+        return new DeploymentSpecBuilder()
+          .withSelector(buildSelector(primaryMeta.getLabels()))
+          .withReplicas(1) // Dependenty track does not support multiple pods (yet)
+          .withTemplate(buildPodTemplate(primary,primaryMeta))
+          .build();
+    }
+
+    private LabelSelector buildSelector(Map<String, String> labels) {
+        return new LabelSelectorBuilder()
+          .addToMatchLabels(labels)
+          .build();
+    }
+
+    private PodTemplateSpec buildPodTemplate(DeptrackResource primary, ObjectMeta primaryMeta) {
+
+        return new PodTemplateSpecBuilder()
+          .withMetadata(primaryMeta)
+          .withSpec(buildPodSpec(primary))
+          .build();
+    }
+
+    private PodSpec buildPodSpec(DeptrackResource primary) {
+
+        // Check for version override
+        String imageVersion = StringUtils.hasText(primary.getSpec().getApiServerVersion())?
+          ":" + primary.getSpec().getApiServerVersion().trim():"";
+
+        // Check for image override
+        String imageName = StringUtils.hasText(primary.getSpec().getApiServerImage())?
+          primary.getSpec().getApiServerImage().trim(): Constants.DEFAULT_API_SERVER_IMAGE;
+
+        //@formatter:off
+        return new PodSpecBuilder(template.getSpec().getTemplate().getSpec())
+          .editContainer(0) // Assumes we have a single container
+            .withImage(imageName + imageVersion)
+            .and()
+          .build();
+        //@formatter:on
+    }
+
+
+    static class Discriminator extends ResourceIDMatcherDiscriminator<Deployment,DeptrackResource> {
+        public Discriminator() {
+            super(COMPONENT, (p) -> new ResourceID(p.getMetadata()
+              .getName() + "-" + COMPONENT, p.getMetadata()
+              .getNamespace()));
+        }
+    }
+
+}

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/resources/deptrack/DeptrackApiServerServiceResource.java

@@ -0,0 +1,52 @@
+package com.baeldung.operators.deptrack.resources.deptrack;
+
+import static com.baeldung.operators.deptrack.resources.deptrack.BuilderHelper.fromPrimary;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import io.fabric8.kubernetes.api.model.ObjectMeta;
+import io.fabric8.kubernetes.api.model.Service;
+import io.fabric8.kubernetes.api.model.ServiceBuilder;
+import io.javaoperatorsdk.operator.api.reconciler.Context;
+import io.javaoperatorsdk.operator.api.reconciler.ResourceIDMatcherDiscriminator;
+import io.javaoperatorsdk.operator.processing.dependent.kubernetes.CRUDKubernetesDependentResource;
+import io.javaoperatorsdk.operator.processing.dependent.kubernetes.KubernetesDependent;
+import io.javaoperatorsdk.operator.processing.event.ResourceID;
+
+@KubernetesDependent(resourceDiscriminator = DeptrackApiServerServiceResource.Discriminator.class)
+public class DeptrackApiServerServiceResource extends CRUDKubernetesDependentResource<Service, DeptrackResource> {
+
+    public static final String COMPONENT = "api-server-service";
+
+    private Service template;
+    public DeptrackApiServerServiceResource() {
+        super(Service.class);
+        this.template = BuilderHelper.loadTemplate(Service.class, "templates/api-server-service.yaml");
+    }
+
+    @Override
+    protected Service desired(DeptrackResource primary, Context<DeptrackResource> context) {
+
+        ObjectMeta meta = fromPrimary(primary,COMPONENT)
+          .build();
+
+        Map<String, String> selector = new HashMap<>(meta.getLabels());
+        selector.put("component", DeptrackApiServerDeploymentResource.COMPONENT);
+
+        return new ServiceBuilder(template)
+          .withMetadata(meta)
+          .editSpec()
+            .withSelector(selector)
+          .endSpec()
+          .build();
+    }
+
+
+    static class Discriminator extends ResourceIDMatcherDiscriminator<Service,DeptrackResource> {
+        public Discriminator() {
+            super(COMPONENT, (p) -> new ResourceID(p.getMetadata().getName() + "-" + COMPONENT,p.getMetadata().getNamespace()));
+        }
+    }
+
+}

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/resources/deptrack/DeptrackFrontendDeploymentResource.java

@@ -0,0 +1,102 @@
+package com.baeldung.operators.deptrack.resources.deptrack;
+
+import static com.baeldung.operators.deptrack.resources.deptrack.BuilderHelper.fromPrimary;
+
+import java.util.Map;
+
+import org.springframework.util.StringUtils;
+
+import com.baeldung.operators.deptrack.resources.Constants;
+
+import io.fabric8.kubernetes.api.model.LabelSelector;
+import io.fabric8.kubernetes.api.model.LabelSelectorBuilder;
+import io.fabric8.kubernetes.api.model.ObjectMeta;
+import io.fabric8.kubernetes.api.model.PodSpec;
+import io.fabric8.kubernetes.api.model.PodSpecBuilder;
+import io.fabric8.kubernetes.api.model.PodTemplateSpec;
+import io.fabric8.kubernetes.api.model.PodTemplateSpecBuilder;
+import io.fabric8.kubernetes.api.model.apps.Deployment;
+import io.fabric8.kubernetes.api.model.apps.DeploymentBuilder;
+import io.fabric8.kubernetes.api.model.apps.DeploymentSpec;
+import io.fabric8.kubernetes.api.model.apps.DeploymentSpecBuilder;
+import io.javaoperatorsdk.operator.api.reconciler.Context;
+import io.javaoperatorsdk.operator.api.reconciler.ResourceIDMatcherDiscriminator;
+import io.javaoperatorsdk.operator.processing.dependent.kubernetes.CRUDKubernetesDependentResource;
+import io.javaoperatorsdk.operator.processing.dependent.kubernetes.KubernetesDependent;
+import io.javaoperatorsdk.operator.processing.event.ResourceID;
+
+@KubernetesDependent(resourceDiscriminator = DeptrackFrontendDeploymentResource.Discriminator.class)
+public class DeptrackFrontendDeploymentResource extends CRUDKubernetesDependentResource<Deployment, DeptrackResource> {
+    public static final String COMPONENT = "frontend";
+    private Deployment template;
+
+    public DeptrackFrontendDeploymentResource() {
+        super(Deployment.class);
+        this.template = BuilderHelper.loadTemplate(Deployment.class, "templates/frontend-deployment.yaml");
+    }
+
+    @Override
+    protected Deployment desired(DeptrackResource primary, Context<DeptrackResource> context) {
+
+        ObjectMeta meta = fromPrimary(primary,COMPONENT)
+          .build();
+
+        return new DeploymentBuilder(template).withMetadata(meta)
+          .withSpec(buildSpec(primary, meta))
+          .build();
+    }
+
+    private DeploymentSpec buildSpec(DeptrackResource primary, ObjectMeta primaryMeta) {
+
+        return new DeploymentSpecBuilder().withSelector(buildSelector(primaryMeta.getLabels()))
+          .withReplicas(1) // Dependency track does not support multiple pods (yet)
+          .withTemplate(buildPodTemplate(primary, primaryMeta))
+          .build();
+    }
+
+    private LabelSelector buildSelector(Map<String, String> labels) {
+        return new LabelSelectorBuilder().addToMatchLabels(labels)
+          .build();
+    }
+
+    private PodTemplateSpec buildPodTemplate(DeptrackResource primary, ObjectMeta primaryMeta) {
+
+        return new PodTemplateSpecBuilder().withMetadata(primaryMeta)
+          .withSpec(buildPodSpec(primary))
+          .build();
+    }
+
+    private PodSpec buildPodSpec(DeptrackResource primary) {
+
+        // Check for version override
+        String imageVersion = StringUtils.hasText(primary.getSpec()
+          .getFrontendVersion()) ? ":" + primary.getSpec()
+          .getFrontendVersion()
+          .trim() : "";
+
+        // Check for image override
+        String imageName = StringUtils.hasText(primary.getSpec()
+          .getFrontendImage()) ? primary.getSpec()
+          .getFrontendImage()
+          .trim() : Constants.DEFAULT_FRONTEND_IMAGE;
+
+        return new PodSpecBuilder(template.getSpec().getTemplate().getSpec())
+          .editContainer(0)
+            .withImage(imageName + imageVersion)
+            .editFirstEnv()
+              .withName("API_BASE_URL")
+              .withValue("https://" + primary.getSpec().getIngressHostname())
+            .endEnv()
+          .and()
+          .build();
+    }
+
+    static class Discriminator extends ResourceIDMatcherDiscriminator<Deployment,DeptrackResource> {
+        public Discriminator() {
+            super(COMPONENT, (p) -> new ResourceID(p.getMetadata()
+              .getName() + "-" + COMPONENT, p.getMetadata()
+              .getNamespace()));
+        }
+    }
+
+}

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/resources/deptrack/DeptrackFrontendServiceResource.java

@@ -0,0 +1,59 @@
+package com.baeldung.operators.deptrack.resources.deptrack;
+
+import static com.baeldung.operators.deptrack.resources.deptrack.BuilderHelper.fromPrimary;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import io.fabric8.kubernetes.api.model.ObjectMeta;
+import io.fabric8.kubernetes.api.model.Service;
+import io.fabric8.kubernetes.api.model.ServiceBuilder;
+import io.javaoperatorsdk.operator.api.reconciler.Context;
+import io.javaoperatorsdk.operator.api.reconciler.ResourceIDMatcherDiscriminator;
+import io.javaoperatorsdk.operator.processing.dependent.kubernetes.CRUDKubernetesDependentResource;
+import io.javaoperatorsdk.operator.processing.dependent.kubernetes.KubernetesDependent;
+import io.javaoperatorsdk.operator.processing.event.ResourceID;
+
+@KubernetesDependent(resourceDiscriminator = DeptrackFrontendServiceResource.Discriminator.class)
+public class DeptrackFrontendServiceResource extends CRUDKubernetesDependentResource<Service, DeptrackResource> {
+
+    public static final String COMPONENT = "frontend-service";
+
+    private Service template;
+    public DeptrackFrontendServiceResource() {
+        super(Service.class);
+        this.template = BuilderHelper.loadTemplate(Service.class, "templates/frontend-service.yaml");
+    }
+
+    @Override
+    protected Service desired(DeptrackResource primary, Context<DeptrackResource> context) {
+
+        ObjectMeta meta = fromPrimary(primary,COMPONENT)
+          .build();
+
+        Map<String, String> selector = new HashMap<>(meta.getLabels());
+        selector.put("component", DeptrackFrontendDeploymentResource.COMPONENT);
+
+        return new ServiceBuilder(template)
+          .withMetadata(meta)
+          .editSpec()
+          .withSelector(selector)
+          .endSpec()
+          .build();
+    }
+
+//    static class Discriminator implements ResourceDiscriminator<Service,DeptrackResource> {
+//        @Override
+//        public Optional<Service> distinguish(Class<Service> resource, DeptrackResource primary, Context<DeptrackResource> context) {
+//            var ies = context.eventSourceRetriever().getResourceEventSourceFor(Service.class,COMPONENT);
+//            return ies.getSecondaryResource(primary);
+//        }
+//    }
+
+    static class Discriminator extends ResourceIDMatcherDiscriminator<Service,DeptrackResource> {
+        public Discriminator() {
+            super(COMPONENT, (p) -> new ResourceID(p.getMetadata().getName() + "-" + COMPONENT,p.getMetadata().getNamespace()));
+        }
+    }
+
+}

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/resources/deptrack/DeptrackIngressResource.java

@@ -0,0 +1,79 @@
+package com.baeldung.operators.deptrack.resources.deptrack;
+
+import static com.baeldung.operators.deptrack.resources.deptrack.BuilderHelper.fromPrimary;
+
+import io.fabric8.kubernetes.api.model.ObjectMeta;
+import io.fabric8.kubernetes.api.model.networking.v1.HTTPIngressRuleValue;
+import io.fabric8.kubernetes.api.model.networking.v1.HTTPIngressRuleValueBuilder;
+import io.fabric8.kubernetes.api.model.networking.v1.Ingress;
+import io.fabric8.kubernetes.api.model.networking.v1.IngressBuilder;
+import io.javaoperatorsdk.operator.api.reconciler.Context;
+import io.javaoperatorsdk.operator.processing.dependent.kubernetes.CRUDKubernetesDependentResource;
+import io.javaoperatorsdk.operator.processing.dependent.kubernetes.KubernetesDependent;
+
+@KubernetesDependent
+public class DeptrackIngressResource  extends CRUDKubernetesDependentResource<Ingress,DeptrackResource> {
+
+    private static final String COMPONENT = "ingress";
+    private final Ingress template;
+
+    public DeptrackIngressResource() {
+        super(Ingress.class);
+        this.template = BuilderHelper.loadTemplate(Ingress.class, "templates/ingress.yaml");
+    }
+
+    @Override
+    protected Ingress desired(DeptrackResource primary, Context<DeptrackResource> context) {
+
+        ObjectMeta meta = fromPrimary(primary,COMPONENT)
+          .build();
+
+        return new IngressBuilder(template)
+          .withMetadata(meta)
+          .editSpec()
+            .editDefaultBackend()
+              .editOrNewService()
+                .withName(primary.getFrontendServiceName())
+              .endService()
+            .endDefaultBackend()
+          .editFirstRule()
+            .withHost(primary.getSpec().getIngressHostname())
+            .withHttp(buildHttpRule(primary))
+          .endRule()
+          .endSpec()
+          .build();
+
+    }
+
+    private HTTPIngressRuleValue buildHttpRule(DeptrackResource primary) {
+
+        return new HTTPIngressRuleValueBuilder()
+          // Backend route
+          .addNewPath()
+            .withPath("/api")
+            .withPathType("Prefix")
+            .withNewBackend()
+              .withNewService()
+                .withName(primary.getApiServerServiceName())
+                .withNewPort()
+                  .withName("http")
+                .endPort()
+              .endService()
+            .endBackend()
+          .endPath()
+          //  Frontend route
+          .addNewPath()
+            .withPath("/")
+              .withPathType("Prefix")
+                .withNewBackend()
+                  .withNewService()
+                    .withName(primary.getFrontendServiceName())
+                    .withNewPort()
+                      .withName("http")
+                    .endPort()
+                  .endService()
+                .endBackend()
+              .endPath()
+          .build();
+    }
+}

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/resources/deptrack/DeptrackResource.java

@@ -0,0 +1,23 @@
+package com.baeldung.operators.deptrack.resources.deptrack;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+import io.fabric8.kubernetes.api.model.Namespaced;
+import io.fabric8.kubernetes.client.CustomResource;
+import io.fabric8.kubernetes.model.annotation.Group;
+import io.fabric8.kubernetes.model.annotation.Version;
+
+@Group("com.baeldung")
+@Version("v1")
+public class DeptrackResource extends CustomResource<DeptrackSpec, DeptrackStatus>  implements Namespaced {
+
+    @JsonIgnore
+    public String getFrontendServiceName() {
+        return this.getMetadata().getName() + "-" + DeptrackFrontendServiceResource.COMPONENT;
+    }
+
+    @JsonIgnore
+    public String getApiServerServiceName() {
+        return this.getMetadata().getName() + "-" + DeptrackApiServerServiceResource.COMPONENT;
+    }
+}

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/resources/deptrack/DeptrackSpec.java

@@ -0,0 +1,32 @@
+package com.baeldung.operators.deptrack.resources.deptrack;
+
+import java.util.Map;
+
+import lombok.Data;
+
+@Data
+public class DeptrackSpec {
+
+    // Images
+    private String apiServerImage = "dependencytrack/apiserver";
+    private String apiServerVersion = "";
+
+    private String frontendImage = "dependencytrack/frontend";
+    private String frontendVersion = "";
+
+    // PVC settings: NOT IMPLEMENTED
+    private String pvcClass = ""; // Use default storage class
+    private String pvcSize = "10Gi";
+
+
+    // Database settings: NOT IMPLEMENTED
+    private String dbUrl;
+    private String dbDriver = "org.postgresql.Driver";
+    private String dbSecret;
+
+
+    // Ingress settings
+    private String ingressHostname;
+    private Map<String,String> ingressAnnotations;
+
+}

kubernetes-modules/k8s-operator/src/main/java/com/baeldung/operators/deptrack/resources/deptrack/DeptrackStatus.java

@@ -0,0 +1,6 @@
+package com.baeldung.operators.deptrack.resources.deptrack;
+
+import io.javaoperatorsdk.operator.api.ObservedGenerationAwareStatus;
+
+public class DeptrackStatus extends ObservedGenerationAwareStatus {
+}

kubernetes-modules/k8s-operator/src/main/logback.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

kubernetes-modules/k8s-operator/src/main/resources/application.properties

@@ -0,0 +1 @@
+management.endpoint.health.probes.enabled=true

kubernetes-modules/k8s-operator/src/main/resources/templates/api-server-deployment.yaml

@@ -0,0 +1,53 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: deptrack-api
+  namespace: deptrack
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      ManagedBy: deptrack-operator
+      component: api-server
+  template:
+    metadata:
+      labels:
+        ManagedBy: deptrack-operator
+        component: api-server
+    spec:
+      containers:
+        - name: main
+          image: dependencytrack/apiserver:4.10.1
+          ports:
+            - containerPort: 8080
+              name: http
+              protocol: TCP
+          readinessProbe:
+            failureThreshold: 3
+            httpGet:
+              path: /
+              port: http
+              scheme: HTTP
+            initialDelaySeconds: 60
+            periodSeconds: 10
+            successThreshold: 1
+            timeoutSeconds: 2
+          livenessProbe:
+            failureThreshold: 3
+            httpGet:
+              path: /api/version
+              port: http
+              scheme: HTTP
+            initialDelaySeconds: 60
+            periodSeconds: 10
+            successThreshold: 1
+            timeoutSeconds: 2
+          resources:
+            limits:
+              cpu: "2"
+              memory: 8Gi
+            requests:
+              cpu: "1"
+              memory: 2Gi
+      restartPolicy: Always
+

kubernetes-modules/k8s-operator/src/main/resources/templates/api-server-pvc.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: deptrack-frontend
+  namespace: deptrack
+spec:
+  accessModes:
+    - ReadWriteOnce
+  resources:
+    requests:
+      storage: 8Gi

kubernetes-modules/k8s-operator/src/main/resources/templates/api-server-service.yaml

@@ -0,0 +1,19 @@
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    ManagedBy: deptrack-operator
+    component: api-server-service
+  name: deptrack-api-server
+  namespace: deptrack
+spec:
+  ports:
+    - name: http
+      port: 8080
+      protocol: TCP
+      targetPort: 8080
+  selector:
+    ManagedBy: deptrack-operator
+    component: api-server
+  sessionAffinity: None
+  type: ClusterIP

kubernetes-modules/k8s-operator/src/main/resources/templates/frontend-deployment.yaml

@@ -0,0 +1,46 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: deptrack-frontend
+  namespace: deptrack
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      ManagedBy: deptrack-operator
+      component: frontend
+  template:
+    metadata:
+      labels:
+        ManagedBy: deptrack-operator
+        component: frontend
+    spec:
+      containers:
+        - name: main
+          env:
+            - name: API_BASE_URL
+              value: https://example.com
+          image: dependencytrack/frontend
+          imagePullPolicy: Always
+          livenessProbe:
+            failureThreshold: 3
+            httpGet:
+              path: /
+              port: http
+              scheme: HTTP
+            periodSeconds: 10
+            successThreshold: 1
+            timeoutSeconds: 1
+          ports:
+            - containerPort: 8080
+              name: http
+              protocol: TCP
+          readinessProbe:
+            failureThreshold: 3
+            httpGet:
+              path: /
+              port: http
+              scheme: HTTP
+            periodSeconds: 10
+            successThreshold: 1
+            timeoutSeconds: 1

kubernetes-modules/k8s-operator/src/main/resources/templates/frontend-service.yaml

@@ -0,0 +1,19 @@
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    ManagedBy: deptrack-operator
+    component: frontend-service
+  name: deptrack-frontend
+  namespace: deptrack
+spec:
+  ports:
+    - name: http
+      port: 8080
+      protocol: TCP
+      targetPort: 8080
+  selector:
+    ManagedBy: deptrack-operator
+    component: frontend
+  sessionAffinity: None
+  type: ClusterIP

kubernetes-modules/k8s-operator/src/main/resources/templates/ingress.yaml

@@ -0,0 +1,33 @@
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  annotations:
+  labels:
+    ManagedBy: terraform
+    component: ingress
+  name: deptrack-ingress
+  namespace: deptrack
+spec:
+  defaultBackend:
+    service:
+      name: deptrack-frontend
+      port:
+        name: http
+  rules:
+    - host: example.com
+      http:
+        paths:
+          - backend:
+              service:
+                name: deptrack-api-server
+                port:
+                  name: http
+            path: /api
+            pathType: Prefix
+          - backend:
+              service:
+                name: deptrack-frontend
+                port:
+                  name: http
+            path: /
+            pathType: Prefix

kubernetes-modules/k8s-operator/src/test/java/com/baeldung/operators/deptrack/ApplicationUnitTest.java

@@ -0,0 +1,30 @@
+package com.baeldung.operators.deptrack;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+
+import io.fabric8.kubernetes.client.KubernetesClient;
+import io.javaoperatorsdk.operator.springboot.starter.test.EnableMockOperator;
+
+@SpringBootTest
+@EnableMockOperator(crdPaths = "classpath:META-INF/fabric8/deptrackresources.com.baeldung-v1.yml")
+class ApplicationUnitTest {
+    @Autowired
+    KubernetesClient client;
+    @Test
+    void whenContextLoaded_thenCrdRegistered() {
+
+        assertThat(
+          client
+            .apiextensions()
+            .v1()
+            .customResourceDefinitions()
+            .withName("deptrackresources.com.baeldung")
+            .get())
+          .isNotNull();
+    }
+
+}

kubernetes-modules/pom.xml

@@ -18,6 +18,7 @@
         <module>k8s-admission-controller</module>
         <module>kubernetes-spring</module>
         <module>k8s-java-heap-dump</module>
+		<module>k8s-operator</module>
     </modules>
 
 </project>