"no main manifest attribute, in server.war" not using a main class

Question

What I'm trying to do is have Docker run a TomEE 8.0.0 application with Maven. However when compiling the application, it gives me the error from the title no main manifest attribute, in server.war.

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>server</artifactId>
    <version>0.1-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>12</maven.compiler.source>
        <maven.compiler.target>12</maven.compiler.target>
    </properties>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.tomee.maven</groupId>
                <artifactId>tomee-embedded-maven-plugin</artifactId>
                <version>8.0.0</version>
                <configuration>
                    <context>ROOT</context>
                    <containerProperties>
                        <tomee.mp.scan>true</tomee.mp.scan>
                    </containerProperties>
                </configuration>
                <dependencies>
                    <dependency>
                        <groupId>org.apache.tomee</groupId>
                        <artifactId>mp-common</artifactId>
                        <version>8.0.0</version>
                    </dependency>
                </dependencies>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.10.1</version>
                <configuration>
                    <source>8</source>
                    <target>8</target>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.0.0</version>
            </plugin>
            <plugin>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.22.1</version>
            </plugin>
        </plugins>
    </build>
    <packaging>war</packaging>

    <repositories>
        <repository>
            <id>jitpack.io</id>
            <url>https://jitpack.io</url>
        </repository>
    </repositories>

    <dependencies>
        <dependency>
            <groupId>org.apache.tomee</groupId>
            <artifactId>javaee-api</artifactId>
            <version>8.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.eclipse.microprofile</groupId>
            <artifactId>microprofile</artifactId>
            <version>2.0</version>
            <type>pom</type>
            <scope>provided</scope>
            <exclusions>
                <exclusion>
                    <groupId>javax.json</groupId>
                    <artifactId>javax.json.bind-api</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>javax.enterprise</groupId>
                    <artifactId>cdi-api</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>javax.ws.rs</groupId>
                    <artifactId>javax.ws.rs-api</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>javax.json</groupId>
                    <artifactId>javax.json-api</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>javax.annotation</groupId>
                    <artifactId>javax.annotation-api</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.apache.myfaces.core</groupId>
            <artifactId>myfaces-api</artifactId>
            <version>2.3.6</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>8.0.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.13</version>
        </dependency>
        <dependency>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-failsafe-plugin</artifactId>
            <version>3.0.0-M5</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

I've tried the following solutions without avail

My question is, because I'm not using any "main" class within the application, but have TomEE running the application, how can I include the manifest.mf correctly?

Or, if this is not the case, how should I start the application, because currently I run the application with Docker through doing the following command

ENTRYPOINT ["java","-jar","server.war"]

score 1 · Answer 1 · answered May 04 '22 at 15:15

1

From the java tool specs

The java command starts a Java application. It does this by starting the Java Runtime Environment (JRE), loading the specified class, and calling that class's main() method. The method must be declared public and static, it must not return any value, and it must accept a String array as a parameter. The method declaration has the following form:

    public static void main(String[] args)

By default, the first argument that is not an option of the java command is the fully qualified name of the class to be called. If the -jar option is specified, its argument is the name of the JAR file containing class and resource files for the application. The startup class must be indicated by the Main-Class manifest header in its source code.

You're trying to run a war, and unlike a jar it cannot be run standalone but it requires a container; in your case TomEE.

https://github.com/tomitribe/docker-tomee descibes how you should start tomee, and also how to add your war to the image.

answered May 04 '22 at 15:15

Robert Scholte

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I figured as much, however I want to try running docker with tomee embedded in the pom.xml, I found out to run such I'd need to change up my dockerfile and at the end run it with `CMD ["catalina.sh", "run"]`. However I am not certain that the way I set up the pom.xml currently actually supports the embedded tomee. – King Reload May 04 '22 at 18:06
The `tomee-embedded-maven-plugin` doesn't use Docker, it starts TomEE on the same system. If you want to run it with Docker from the pom, search for a docker maven plugin. – Robert Scholte May 04 '22 at 18:28
so what you're saying is that I have to start tomee in the dockerfile and just add the .war file to the running tomee? how does that work with the resources folder that contains .properties files, which is within the application? – King Reload May 04 '22 at 18:37
btw, I've been trying it out and the `ADD / /usr/local/tomee/webapps/` just doesn't want to work at all- mainly because in the docker container the .war file hasn't been made, since the /target directory is in the `.gitignore`, so I've been trying to build the .war file through maven in the dockerfile, but it's just not really working. Do you know of an existing source that could help with this issue, because I haven't really been finding any? – King Reload May 04 '22 at 19:30

score 1 · Accepted Answer · answered May 04 '22 at 20:43

Eventually after puzzling around with the hints from Robert Scholte, which helped me in the search of a solution, the indeed problem wasn't so much in the pom.xml, but more so in the setup of the Dockerfile. Within the old Dockerfile I was trying to run the .war as a .jar file.

Slightly following the setup from https://github.com/tomitribe/docker-tomee I ended up setting up the following Dockerfile

FROM maven:3.8.3-jdk-11-slim AS build
RUN mkdir -p /workspace
WORKDIR /workspace
COPY pom.xml /workspace
COPY src /workspace/src
RUN mvn -B -f pom.xml clean package -DskipTests

FROM openjdk:11-jdk-slim
RUN apt-get update; apt-get -y install curl gpg
ENV PATH /workspace/tomee/bin:$PATH
RUN mkdir -p /workspace/tomee
WORKDIR /workspace/tomee

RUN set -xe; \
  for key in \
  # Matt Hogstrom <hogstrom@apache.org>
  9056B710F1E332780DE7AF34CBAEBE39A46C4CA1 \
  # Jeremy Whitlock <jwhitlock@apache.org>
  F067B8140F5DD80E1D3B5D92318242FE9A0B1183 \
  # Richard Kenneth McGuire (CODE SIGNING KEY) <rickmcguire@apache.org>
  223D3A74B068ECA354DC385CE126833F9CF64915 \
  # Jonathan Gallimore <jgallimore@apache.org>
  DBCCD103B8B24F86FFAAB025C8BB472CD297D428 \
  # Jarek Gawor (CODE SIGNING KEY) <gawor@apache.org>
  7A2744A8A9AAF063C23EB7868EBE7DBE8D050EEF \
  # Jarek Gawor <gawor@apache.org>
  B8B301E6105DF628076BD92C5483E55897ABD9B9 \
  # Andy Gumbrecht (TomEE Code Signing) <agumbrecht@tomitribe.com>
  FAA603D58B1BA4EDF65896D0ED340E0E6D545F97 \
  # Romain Manni-Bucau <rmannibucau@tomitribe.com>
  A57DAF81C1B69921F4BA8723A8DE0A4DB863A7C1 \
  # Mark Struberg (Apache) <struberg@apache.org>
  82D8419BA697F0E7FB85916EE91287822FDB81B1 \
  # David Blevins <dblevins@apache.org>
  B7574789F5018690043E6DD9C212662E12F3E1DD \
  # Xu Hai Hong (Ivan Xu @ Geronimo) <xhhsld@gmail.com>
  C23A3F6F595EBD0F960270CC997C8F1A5BE6E4C1 \
  # Jean-Louis Monteiro (CODE SIGNING KEY) <jlmonteiro@apache.org>
  678F2D98F1FD9643811639FB622B8F2D043F71D8 \
  # Romain Manni-Bucau <rmannibucau@apache.org>
  BDD0BBEB753192957EFC5F896A62FC8EF17D8FEF \
  # Romain Manni-Bucau <rmannibucau@apache.org>
  D11DF12CC2CA4894BDE638B967C1227A2678363C \
  # Roberto Cortez (Apache Signing Key) <radcortez@yahoo.com>
  C92604B0DEC5C62CFF5801E73D4683C24EDC64D1 \
  # David Blevins <dblevins@tomitribe.com>
  626C542EDA7C113814B77AF09C04914D63645D20 \
  # Jean-Louis Monteiro (CODE SIGNING KEY) <jlmonteiro@apache.org>
  3948829384B269D333CC5B98358807C52B4B0E23 \
  # Richard Zowalla (Code Signing Key) <rzo1@apache.org>
  B83D15E72253ED1104EB4FBBDAB472F0E5B8A431 \
  ; do \
    gpg --batch --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys "$key" || \
    gpg --batch --keyserver hkp://pgp.mit.edu:80 --recv-keys "$key" ; \
  done

ENV TOMEE_VER 8.0.11
ENV TOMEE_BUILD plus

RUN set -x \
  && curl -fSL https://dist.apache.org/repos/dist/release/tomee/tomee-${TOMEE_VER}/apache-tomee-${TOMEE_VER}-${TOMEE_BUILD}.tar.gz.asc -o tomee.tar.gz.asc \
  && curl -fSL https://dist.apache.org/repos/dist/release/tomee/tomee-${TOMEE_VER}/apache-tomee-${TOMEE_VER}-${TOMEE_BUILD}.tar.gz.sha512 -o tomee.tar.gz.sha512 \
  && curl -fSL https://dist.apache.org/repos/dist/release/tomee/tomee-${TOMEE_VER}/apache-tomee-${TOMEE_VER}-${TOMEE_BUILD}.tar.gz -o apache-tomee-${TOMEE_VER}-${TOMEE_BUILD}.tar.gz \
  && gpg --batch --verify tomee.tar.gz.asc apache-tomee-${TOMEE_VER}-${TOMEE_BUILD}.tar.gz \
  && echo `cat tomee.tar.gz.sha512` apache-tomee-${TOMEE_VER}-${TOMEE_BUILD}.tar.gz | sha512sum -c - \
  && tar -zxf apache-tomee-${TOMEE_VER}-${TOMEE_BUILD}.tar.gz \
  && mv apache-tomee-${TOMEE_BUILD}-${TOMEE_VER}/* /workspace/tomee \
  && rm apache-tomee-${TOMEE_VER}-${TOMEE_BUILD}.tar.gz \
  && rm -Rf apache-tomee-${TOMEE_BUILD}-${TOMEE_VER} \
  && rm bin/*.bat \
  && rm bin/*.exe \
  && rm bin/*.tar.gz* \
  && rm tomee.tar.gz.asc \
  && rm tomee.tar.gz*

EXPOSE 8080
CMD ["catalina.sh", "run"]

WORKDIR /workspace
COPY --from=build /workspace/target/*.war /workspace/tomee/webapps/server.war

This basically creates a .war file with maven and then ends up using that .war file in the tomee server by adding it at the end using COPY --from=build /workspace/target/*.war /workspace/tomee/webapps/server.war.

"no main manifest attribute, in server.war" not using a main class

2 Answers2