Basically, I added code to an already existing REST API (java, Springboot). when I run it on Intellij there’s no problem and I can use it as intended.
The thing is that I want to test it on a Docker container.
I builded the .jar of the project by using
Build->Build Artifact->project_name.jar->Build
and when I try to docker-compose up I get several problems.

The folder I use contains : a docker-compose.yml, a Dockerfile, and the .jar
I know the first two files are ok as I used them to run a small test project and had no errors.

The first problem I got when building the container is :
no main manifest attribute, in /project_name.jar

My MANIFEST.MF look like this in my IDE :

Manifest-Version: 1.0
Main-Class: com.project.project_name.adapters.api.Application

but in my .jar artifact look like this :

Manifest-Version: 1.0
Implementation-Title: spring-beans
Automatic-Module-Name: spring.beans
Implementation-Version: 5.2.3.RELEASE
Created-By: 1.8.0_232 (Oracle Corporation)

So my first question is why is it different and why is it deleting the part with the Main Class ? And of course how to solve this problem ?

As a temporary solution, I added the Main Class in the MANIFEST.MF by hand in my .jar

By doing so, I get a MANIFEST.MF that look like this :

Manifest-Version: 1.0
Main-Class: com.project.project_name.adapters.api.Application
Implementation-Title: spring-beans
Automatic-Module-Name: spring.beans
Implementation-Version: 5.2.3.RELEASE
Created-By: 1.8.0_232 (Oracle Corporation)

When I try to docker-compose up once again, I get this error :
java.lang.IllegalArgumentException: No auto configuration classes found in META -INF/spring.factories. If you are using a custom packaging, make sure that file is correct.

I’m not really a pro in Springboot, and that’s an ex-coworker who did the first part of the project, but I’m pretty sure it uses custom packaging.

the file spring.factories look like this :

org.springframework.beans.BeanInfoFactory=org.springframework.beans.ExtendedBeanInfoFactory

and I don’t know if this is supposed to be correct or not.
I’m clearly missing something but I don’t really know what, even after looking here for similar problem and potential solution, but nothing did the trick.

Just in case here’s my 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>com.piroux</groupId>
    <artifactId>phoenixrh-backend</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>10</source>
                    <target>10</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <mainClass>com.piroux.phoenixrhbackend.adapters.api.Application</mainClass>
                </configuration>
                <version>2.1.4.RELEASE</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.4.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <version>2.2.4.RELEASE</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>de.bechte.junit</groupId>
            <artifactId>junit-hierarchicalcontextrunner</artifactId>
            <version>4.12.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.45</version>
        </dependency>
        <dependency>
            <groupId>org.testcontainers</groupId>
            <artifactId>testcontainers</artifactId>
            <version>1.14.3</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.testcontainers</groupId>
            <artifactId>mysql</artifactId>
            <version>1.14.3</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

Not sure if any other information is needed, but if so just tell me.