Failed to load Main-Class manifest attribute while running java -jar

If you are working with Spring Boot this will solve your problem:

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <version>1.2.5.RELEASE</version>
            <executions>
                <execution>
                    <goals>
                        <goal>repackage</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>

Reference Guide | Spring Boot Maven Plugin

You have to specifiy it in your pom.xml - This will make your jar executable with all dependencies (replace your.main.class):

<!-- setup jar manifest to executable with dependencies -->
<plugin>
  <artifactId>maven-assembly-plugin</artifactId>
  <configuration>
    <descriptorRefs>
      <descriptorRef>jar-with-dependencies</descriptorRef>
    </descriptorRefs>
    <archive>
      <manifest>
        <mainClass>your.main.class</mainClass>
      </manifest>
    </archive>
  </configuration>
  <executions>
    <execution>
      <phase>package</phase>
      <goals>
       <goal>single</goal>
      </goals>  
    </execution>
  </executions>
</plugin>

check the order of

<plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
</plugin>

it should be above

dockerfile-maven-plugin else repackage will happen

this solved my problem of no main attribute in manifest.

You might be missing Spring Boot Maven Plugin.

<plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
</plugin>