Maven plugin: Skipped dependency module missing from service image

Environment:

• Jib version: 2.6.0
• Build tool: Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)
• JVM: 14.0.2, AdoptOpenJDK
• OS: Linux 5.4.0-52-generic amd64

Description of the issue: Building images from the root folder of a multi-module project, I don’t get functional images: during container startup, the JVM can not find classes from the (skipped) common module

Expected behavior:

Images are functional, i.e. include all dependencies (even if they were marked to “skip” for Jib).

Steps to reproduce:

1. Maven project with three modules common, serviceA, serviceB; the latter two depend on common (via dependencyManagement in the root POM).
2. Configure Jib in the root pom.
3. Run mvn compile jib:dockerBuild

jib-maven-plugin Configuration: Root:

<plugin>
    <groupId>com.google.cloud.tools</groupId>
    <artifactId>jib-maven-plugin</artifactId>
    <version>${jib.version}</version>
    <configuration>
      <skip>true</skip>
      <from>
        <image>gcr.io/distroless/java:11</image>
      </from>
      <to>
        <image>my-service-${project.artifactId}</image>
      </to>
    </configuration>
</plugin>

serviceA, serviceB:

      <plugin>
        <groupId>com.google.cloud.tools</groupId>
        <artifactId>jib-maven-plugin</artifactId>
        <configuration>
          <skip>false</skip>
        </configuration>
      </plugin>

Additional Information: Without <skip>, building in the root folder fails because common doesn’t have a “main” class:

[ERROR] Failed to execute goal com.google.cloud.tools:jib-maven-plugin:2.5.2:build (default-cli) on project commons: Main class was not found, perhaps you should add a mainClass configuration to jib-maven-plugin

[chanseokoh]

Does Maven not resolve this to the sibling module? 🤷‍♂️

It should. Not sure what’s going on.

So, if I were to run mvn -pl serviceA clean package jib:dockerBuild, it wouldn’t work either because commons would silently be forgotten?

You need -am (--also-make) too. That is, mvn -am -pl serviceA clean package jib:dockerBuild.

--also-make - build the specified projects, and any of their dependencies in the reactor

We have a multi-module example, which I think is configured a little bit different than yours. Worth taking a look.

Let us know if you have any questions. If you have a reproducible sample, we can take a look too.

[reitzig]

Maybe? We do have this in serviceA/pom.xml:

<dependency>
    <groupId>our.group</groupId>
    <artifactId>commons</artifactId>
</dependency>

Does Maven not resolve this to the sibling module? 🤷‍♂️

Unfortunately, AFAIK, there is no way a plugin can trigger lifecycle phases (whether it be mvn deploy, mvn install, or mvn compile). For your build to run the compile or package lifecycle, you must give the command.

For example, if you don’t run the package phase, Maven will never create common-…jar for your “common” module, which if existed Jib would containerize as a dependency of “serviceA”. Likewise, if you don’t run the compile phase, Maven will not create .class files, and Jib would miss those compile files. It’s not possible for Jib to run package or compile.

Thanks.

So, if I were to run mvn -pl serviceA clean package jib:dockerBuild, it wouldn’t work either because commons would silently be forgotten? Ugn… -pl commons,serviceA it is, but that’s … sad.

Anyway, it seems that by issue is with Maven, not Jib. Thanks for your help!