KTLN-630 - Kotlin Application Deployment with Docker and Kubernetes (B…

…aeldung#1121)

* feat: deploy kotlin app to k8s

* fix: no tests

kotlin-docker/.gitignore

@@ -0,0 +1,14 @@
+/bin/
+
+#ignore gradle
+.gradle/
+
+
+#ignore build and generated files
+build/
+node/
+out/
+
+#ignore installed node modules and package lock file
+node_modules/
+package-lock.json

kotlin-docker/README.md

@@ -0,0 +1 @@
+## Relevant Articles

kotlin-docker/dockerk8s/Dockerfile

@@ -0,0 +1,11 @@
+# Use an official OpenJDK runtime as a parent image
+FROM openjdk:17-jdk-slim
+
+# Set the working directory in the container
+WORKDIR /app
+
+# Copy the JAR file into the container
+COPY ../target/kotlin-app.jar /app/kotlin-app.jar
+
+# Run the application
+CMD ["java", "-jar", "/app/kotlin-app.jar"]

kotlin-docker/dockerk8s/deployment.yaml

@@ -0,0 +1,19 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: kotlin-app-deployment
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: kotlin-app
+  template:
+    metadata:
+      labels:
+        app: kotlin-app
+    spec:
+      containers:
+        - name: kotlin-app-container
+          image: DOCKER_IMAGE
+          ports:
+            - containerPort: 8080

kotlin-docker/dockerk8s/service.yaml

@@ -0,0 +1,12 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: kotlin-app
+spec:
+  type: NodePort
+  ports:
+    - port: 8080
+      targetPort: 8080
+      nodePort: 30000
+  selector:
+    app: kotlin-app

kotlin-docker/pom.xml

@@ -0,0 +1,95 @@
+<?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>
+    <artifactId>kotlin-docker</artifactId>
+    <name>kotlin-docker</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-3</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../parent-boot-3</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-reflect</artifactId>
+            <version>${kotlin.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-stdlib</artifactId>
+            <version>${kotlin.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>org.jetbrains.kotlin</groupId>
+                <artifactId>kotlin-maven-plugin</artifactId>
+                <version>${kotlin.version}</version>
+                <configuration>
+                    <args>
+                        <arg>-Xjsr305=strict</arg>
+                    </args>
+                    <compilerPlugins>
+                        <plugin>spring</plugin>
+                    </compilerPlugins>
+                </configuration>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.jetbrains.kotlin</groupId>
+                        <artifactId>kotlin-maven-allopen</artifactId>
+                        <version>${kotlin.version}</version>
+                    </dependency>
+                </dependencies>
+            </plugin>
+        </plugins>
+    </build>
+
+    <profiles>
+        <profile>
+            <id>docker-k8s</id>
+            <build>
+                <finalName>kotlin-app</finalName>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-shade-plugin</artifactId>
+                        <version>3.2.4</version>
+                        <executions>
+                            <execution>
+                                <phase>package</phase>
+                                <goals>
+                                    <goal>shade</goal>
+                                </goals>
+                                <configuration>
+                                    <transformers>
+                                        <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                            <mainClass>com.baeldung.dockerk8s.ApplicationKt</mainClass>
+                                        </transformer>
+                                    </transformers>
+                                </configuration>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+</project>

kotlin-docker/src/main/kotlin/com/baeldung/dockerk8s/Application.kt

@@ -0,0 +1,11 @@
+package com.baeldung.dockerk8s
+
+import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.boot.runApplication
+
+@SpringBootApplication
+class Application
+
+fun main(args: Array<String>) {
+    runApplication<Application>(*args)
+}

kotlin-docker/src/main/kotlin/com/baeldung/dockerk8s/HelloController.kt

@@ -0,0 +1,15 @@
+package com.baeldung.dockerk8s
+
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+@RequestMapping("/api")
+class HelloController {
+    @GetMapping("/hello")
+    fun hello(): ResponseEntity<String> {
+        return ResponseEntity.ok("Hello From Docker and Kubernetes!")
+    }
+}

pom.xml

@@ -533,6 +533,7 @@
                 <module>kotlin-blockchain</module>
                 <module>kotlin-testing</module>
                 <module>kotlin-mockito</module>
+                <module>kotlin-docker</module>
                 <!-- <module>kotlin-tornadofx</module> --> <!-- not compatible with Java 9+ -->
                 <module>kotlin-kover</module>
                 <module>ktlint-custom</module>