Update Jenkinsfile

Dockerfile

@@ -0,0 +1,8 @@
+FROM openjdk:8-jre-alpine
+
+EXPOSE 8080
+
+COPY ./target/java-maven-app-*.jar /usr/app/
+WORKDIR /usr/app
+
+CMD java -jar java-maven-app-*.jar

Jenkinsfile

@@ -0,0 +1,71 @@
+#!/usr/bin/env groovy
+
+pipeline {
+    agent any
+    tools {
+        maven 'Maven'
+    }
+    stages {
+        stage('increment version') {
+            steps {
+                script {
+                    echo 'incrementing app version...'
+                    sh 'mvn build-helper:parse-version versions:set \
+                        -DnewVersion=\\\${parsedVersion.majorVersion}.\\\${parsedVersion.minorVersion}.\\\${parsedVersion.nextIncrementalVersion} \
+                        versions:commit'
+                    def matcher = readFile('pom.xml') =~ '<version>(.+)</version>'
+                    def version = matcher[0][1]
+                    env.IMAGE_NAME = "$version-$BUILD_NUMBER"
+                }
+            }
+        }
+        stage('build app') {
+            steps {
+                script {
+                    echo "building the application..."
+                    sh 'mvn clean package'
+                }
+            }
+        }
+        stage('build image') {
+            steps {
+                script {
+                    echo "building the docker image..."
+                    withCredentials([usernamePassword(credentialsId: 'docker-hub', passwordVariable: 'PASS', usernameVariable: 'USER')]) {
+                        sh "docker build -t nanajanashia/demo-app:${IMAGE_NAME} ."
+                        sh "echo $PASS | docker login -u $USER --password-stdin"
+                        sh "docker push nanajanashia/demo-app:${IMAGE_NAME}"
+                    }
+                }
+            }
+        }
+        stage('deploy') {
+            steps {
+                script {
+                    withKubeConfig([credentialsId: 'k8s-credentials', serverUrl: 'https://7293fae4-4c9d-4629-bc82-262d0a2b8e3c.eu-central-2.linodelke.net']) {
+                        withCredentials([usernamePassword(credentialsId: 'docker-hub', passwordVariable: 'PASS', usernameVariable: 'USER')]) {
+                            sh "kubectl create secret docker-registry my-registry-key --docker-server=docker.io --docker-username=$USER --docker-password=$PASS"
+                        }
+                        sh 'envsubst < kubernetes/deployment.yaml | kubectl apply -f -'
+                    }
+                }
+            }
+        }
+        stage('commit version update') {
+            steps {
+                script {
+                    withCredentials([usernamePassword(credentialsId: 'gitlab-credentials', passwordVariable: 'PASS', usernameVariable: 'USER')]) {
+                        // git config here for the first time run
+                        sh 'git config --global user.email "jenkins@example.com"'
+                        sh 'git config --global user.name "jenkins"'
+
+                        sh "git remote set-url origin https://${USER}:${PASS}@gitlab.com/nanuchi/java-maven-app.git"
+                        sh 'git add .'
+                        sh 'git commit -m "ci: version bump"'
+                        sh 'git push origin HEAD:jenkins-jobs'
+                    }
+                }
+            }
+        }
+    }
+}

kubernetes/deployment.yaml

@@ -0,0 +1,25 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: java-maven-app
+  labels:
+    app: java-maven-app
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      app: java-maven-app
+  template:
+    metadata:
+      labels:
+        app: java-maven-app
+    spec:
+      imagePullSecrets:
+        - name: my-registry-key
+      containers:
+      - name: java-maven-app
+        image: nanajanashia/demo-app:$IMAGE_NAME
+        imagePullPolicy: Always
+        ports:
+        - containerPort: 8080
+

kubernetes/service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: java-maven-app
+spec:
+  selector:
+    app: java-maven-app
+  ports:
+    - protocol: TCP
+      port: 80
+      targetPort: 8080

pom.xml

@@ -6,7 +6,24 @@
 
     <groupId>com.example</groupId>
     <artifactId>java-maven-app</artifactId>
-    <version>1.0-SNAPSHOT</version>
+    <version>1.1.0-SNAPSHOT</version>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <version>2.3.5.RELEASE</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>repackage</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
 
     <dependencies>
         <dependency>

script.groovy

@@ -0,0 +1,19 @@
+def buildJar() {
+    echo "building the application..."
+    sh 'mvn package'
+} 
+
+def buildImage() {
+    echo "building the docker image..."
+    withCredentials([usernamePassword(credentialsId: 'docker-hub-repo', passwordVariable: 'PASS', usernameVariable: 'USER')]) {
+        sh 'docker build -t nanajanashia/demo-app:jma-2.0 .'
+        sh "echo $PASS | docker login -u $USER --password-stdin"
+        sh 'docker push nanajanashia/demo-app:jma-2.0'
+    }
+} 
+
+def deployApp() {
+    echo 'deploying the application...'
+} 
+
+return this