"Failed to determine project directory for dev mode" spring jar in container

Flow
1

I have a Vaadin application running from a Springboot bootable jar. That jar is deployed to a linux server, and all it needs is an application-default.properties file with some database connection settings to start. Those two files can be copied to any folder on my development machine and the application starts correctly.

If I create a container with the same two files, like so:

FROM azul/zulu-openjdk:23-latest
COPY ../../../target/*-boot.jar app.jar
COPY ../../../target/application-default.properties application-default.properties
EXPOSE 8080
ENTRYPOINT ["java", "-jar", "/app.jar"]

It starts up correctly, but just prior to going online fails with:

Caused by: java.lang.IllegalStateException: Failed to determine project directory for dev mode. Directory '/' does not look like a Maven or Gradle project. Ensure that you have run the prepare-frontend Maven goal, which generates 'flow-build-info.json', prior to deploying your application
        at com.vaadin.flow.server.AbstractConfiguration.getProjectFolder(AbstractConfiguration.java:238)
        at com.vaadin.flow.server.AbstractConfiguration.getJavaResourceFolder(AbstractConfiguration.java:261)
        at com.vaadin.base.devserver.startup.DevModeInitializer.initDevModeHandler(DevModeInitializer.java:229)
        at com.vaadin.base.devserver.DevModeHandlerManagerImpl.initDevModeHandler(DevModeHandlerManagerImpl.java:104)
        at com.vaadin.flow.spring.VaadinServletContextInitializer$DevModeServletContextListener.failFastContextInitialized(VaadinServletContextInitializer.java:593)
        at com.vaadin.flow.spring.VaadinServletContextInitializer$FailFastServletContextListener.contextInitialized(VaadinServletContextInitializer.java:202)

The pom calls prepare-frontend on every build, and build-frontend when building the bootable jar (-Pproduction).

		<profile>
			<id>production</id>
            <dependencies>
                <dependency>
                    <groupId>com.vaadin</groupId>
                    <artifactId>vaadin-core</artifactId>
                    <exclusions>
                        <exclusion>
                            <groupId>com.vaadin</groupId>
                            <artifactId>vaadin-dev</artifactId>
                        </exclusion>
                    </exclusions>
                </dependency>
            </dependencies>
			<build>
				<plugins>
					<plugin>
						<groupId>com.vaadin</groupId>
						<artifactId>vaadin-maven-plugin</artifactId>
						<version>${vaadin.version}</version>
						<executions>
							<execution>
								<id>frontend</id>
								<phase>compile</phase>
								<goals>
									<goal>build-frontend</goal>
								</goals>
								<configuration>
                                    <forceProductionBuild>true</forceProductionBuild>
                                </configuration>
							</execution>
						</executions>
					</plugin>
				</plugins>
			</build>
		</profile>

I’ve tried adding -Dvaadin.productionMode=true to the container’s ENTRYPOINT, but that does not matter. The META-INF\VAADIN\config\flow-build-info.json is present in the bootable jar:

{
  "productionMode": true,
  "eagerServerLoad": false,
  "react.enable": true,
  "applicationIdentifier": "app-48e80009bd0b96712300635e8696e2b9d909060f39d024e879de084ad1f92d4a"
}

Since the bootable jar can be started from anywhere already, why is there an issue in the container?

2

Seems like the dev mode dependencies are somehow sneaking into the production build. You could check with mvn dependency:tree -Pproduction to see if there’s some additional exclude that you need to add.

3

God, always when you’ve just made a post to a forum: I’m messing up my container builds. The application is starting now, I was barking up the wrong tree.

1 Like