Deploying Spring + a front end framework

[KevinArnall]

If one wants to use a front end framework in conjunction with spring, your frontend files need to be in the same project as your spring application, i.e. in ~/frontend. You can use a maven plugin like https://github.com/eirslett/frontend-maven-plugin to automatically build your front end and include it in the /target folder so maven can package it correctly. So your pom.xml should include

<build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>com.github.eirslett</groupId>
                <artifactId>frontend-maven-plugin</artifactId>
                <version>1.6</version>
                <configuration>
                    <workingDirectory>frontend</workingDirectory>
                    <installDirectory>target</installDirectory>
                </configuration>
                <executions>
                    <execution>
                        <id>install node and npm</id>
                        <goals>
                            <goal>install-node-and-npm</goal>
                        </goals>
                        <configuration>
                            <nodeVersion>v12.6.0</nodeVersion>
                            <npmVersion>6.9.0</npmVersion>
                        </configuration>
                    </execution>
                    <execution>
                        <id>npm install</id>
                        <goals>
                            <goal>npm</goal>
                        </goals>
                        <configuration>
                            <arguments>install</arguments>
                        </configuration>
                    </execution>
                    <execution>
                        <id>npm run build</id>
                        <goals>
                            <goal>npm</goal>
                        </goals>
                        <configuration>
                            <arguments>run build</arguments>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

            <plugin>
                <artifactId>maven-antrun-plugin</artifactId>
                <executions>
                    <execution>
                        <phase>generate-resources</phase>
                        <configuration>
                            <target>
                                <copy todir="${project.build.directory}/classes/public">
                                    <fileset dir="${project.basedir}/frontend/build"/>
                                </copy>
                            </target>
                        </configuration>
                        <goals>
                            <goal>run</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

In addition, the command to build the jar is mvn clean install rather than ./mvnw package so your .cods file should look like this

BUILD_COMMAND='mvn clean install'
JAR_FILE=target/FILENAME.jar