fix

Dockerfile

@@ -0,0 +1,8 @@
+FROM openjdk:8-jre-alpine
+
+EXPOSE 8080
+
+COPY ./target/java-maven-app-1.0-SNAPSHOT.jar /usr/app/
+WORKDIR /usr/app
+
+ENTRYPOINT ["java", "-jar", "java-maven-app-1.0-SNAPSHOT.jar"]

Jenkinsfile

@@ -0,0 +1,50 @@
+#!/usr/bin/env groovy
+
+library identifier: 'jenkins-shared-library@master', retriever: modernSCM(
+        [$class: 'GitSCMSource',
+         remote: 'https://gitlab.com/nanuchi/jenkins-shared-library.git',
+         credentialsId: 'gitlab-credentials'
+        ]
+)
+
+
+def gv
+
+pipeline {
+    agent any
+    tools {
+        maven 'Maven'
+    }
+    stages {
+        stage("init") {
+            steps {
+                script {
+                    gv = load "script.groovy"
+                }
+            }
+        }
+        stage("build jar") {
+            steps {
+                script {
+                    buildJar()
+                }
+            }
+        }
+        stage("build and push image") {
+            steps {
+                script {
+                    buildImage 'nanajanashia/demo-app:jma-3.0'
+                    dockerLogin()
+                    dockerPush 'nanajanashia/demo-app:jma-3.0'
+                }
+            }
+        }
+        stage("deploy") {
+            steps {
+                script {
+                    gv.deployApp()
+                }
+            }
+        }
+    }
+}

script.groovy

@@ -0,0 +1,5 @@
+def deployApp() {
+    echo 'deploying the application...'
+}
+
+return this