java.lang.NoClassDefFoundError on run dockerfile after build - docker

Question

i want to dockerize my maven project. My pom.xml looks like
<?xml version="1.0" encoding="UTF-8"?>
4.0.0
<groupId>de.fhws.biedermann.webshop</groupId>
<artifactId>progPorj</artifactId>
<version>1.0-SNAPSHOT</version>
<build>
<finalName>webshop</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>lib/</classpathPrefix>
<mainClass>de.fhws.biedermann.webshop.Start</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.4</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.owlike</groupId>
<artifactId>genson</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-io</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-core</artifactId>
<version>${tomcat.version}</version>
</dependency>
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
<version>${tomcat.version}</version>
</dependency>
<dependency>
<groupId>javax.ws.rs</groupId>
<artifactId>javax.ws.rs-api</artifactId>
<version>2.1</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.core</groupId>
<artifactId>jersey-server</artifactId>
<version>${jersey.version}</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.containers</groupId>
<artifactId>jersey-container-servlet</artifactId>
<version>${jersey.version}</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.containers</groupId>
<artifactId>jersey-container-servlet-core</artifactId>
<version>${jersey.version}</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.ext</groupId>
<artifactId>jersey-declarative-linking</artifactId>
<version>${jersey.version}</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.media</groupId>
<artifactId>jersey-media-multipart</artifactId>
<version>${jersey.version}</version>
</dependency>
<dependency>
<groupId>com.squareup.okhttp3</groupId>
<artifactId>okhttp</artifactId>
<version>3.7.0</version>
</dependency>
<dependency>
<groupId>commons-lang</groupId>
<artifactId>commons-lang</artifactId>
<version>2.6</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.inject</groupId>
<artifactId>jersey-hk2</artifactId>
<version>${jersey.version}</version>
</dependency>
<dependency>
<groupId>jakarta.ws.rs</groupId>
<artifactId>jakarta.ws.rs-api</artifactId>
<version>2.1.6</version>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>28.2-android</version>
</dependency>
<dependency>
<groupId>org.xerial</groupId>
<artifactId>sqlite-jdbc</artifactId>
<version>3.36.0.3</version>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-api</artifactId>
<version>5.8.2</version>
</dependency>
<dependency>
<groupId>org.json</groupId>
<artifactId>json</artifactId>
<version>20180130</version>
</dependency>
</dependencies>
<properties>
<maven.compiler.source>16</maven.compiler.source>
<maven.compiler.target>16</maven.compiler.target>
<tomcat.version>8.5.13</tomcat.version>
<jersey.version>2.31</jersey.version>
</properties>
and my dockerfile
#
# Build stage
#
FROM maven:3.8.4-openjdk-17 AS build
COPY . /home/app
RUN mvn -f /home/app/pom.xml clean package
#
# Package stage
#
FROM openjdk:16-alpine3.13
COPY --from=build /home/app/target/webshop.jar /usr/local/lib/webshop.jar
EXPOSE 8080
ENTRYPOINT ["java","-jar","/usr/local/lib/webshop.jar"]
When i build this file, everything works, but on running i get an
Error: Unable to initialize main class de.fhws.biedermann.webshop.Start
Caused by: java.lang.NoClassDefFoundError: org/apache/catalina/WebResourceRoot
What should i do?
Thanks

Answer 1

I think in your build stage you didn't specify your WORKDIR which possibly defaults to /home and your mvn build is in /home/target instead of /home/app/target. Perhaps you can try to add:
...
COPY . /home/app
WORKDIR /home/app #<==== set correct working directory for maven
RUN mvn -f /home/app/pom.xml clean package
...
This might make your Jar available to the application and it can run.