Add documentation tip showing how to configure publishRegistry maven properties from the command line

[ffroliva]

If I have a private registry and I want to publish the generated docker image I need to provide username, password, and url in the maven pom.xml.

...
<plugin>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-maven-plugin</artifactId>
  <configuration>
    <image>
      <name>${docker.image.prefix}/${project.artifactId}:${project.version}</name>
    </image>
    <docker>
      <publishRegistry>
        <username>USERNAME</username>
        <password>PASSWORD</password>
        <url>URL</url>
      </publishRegistry>
    </docker>
  </configuration>
  <executions>
    <execution>
      <goals>
        <goal>build-image</goal>
      </goals>
    </execution>
  </executions>
</plugin>

I would like to be able to send this variables over the command line as follows:

mvn spring-boot:build-image \
-DskipTests \
-Dspring-boot.build-image.imageName=nexus:8870/rcl/op-risk-ui:test \
-Dspring-boot.build-image.publishRegistry.username=<USERNAME> \
-Dspring-boot.build-image.publishRegistry.password=<PASSWORD>
-Dspring-boot.build-image.publishRegistry.url=<URL>

Currently the following variables doesnt exist for the command line:

• -Dspring-boot.build-image.publishRegistry.username
• -Dspring-boot.build-image.publishRegistry.password
• Dspring-boot.build-image.publishRegistry.url

I believe they should be created here:
https://github.com/spring-projects/spring-boot/blob/82b90d57496ba85be316b9eb88a36d81f2cc9baa/spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/BuildImageMojo.java

[philwebb]

I'm not sure how easy this will be to fix. I suspect that we can't just add a property attribute to the docker @Parameter because it's a complex type. We'll need to dig into the internals of Maven.

In the meantime, you can probably do something like this:

<plugin>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-maven-plugin</artifactId>
  <configuration>
    <image>
      <name>${docker.image.prefix}/${project.artifactId}:${project.version}</name>
    </image>
    <docker>
      <publishRegistry>
        <username>${spring-boot.build-image.publishRegistry.username}</username>
        <password>${spring-boot.build-image.publishRegistry.password}</password>
        <url>${spring-boot.build-image.publishRegistry.url}</url>
      </publishRegistry>
    </docker>
  </configuration>
  <executions>
    <execution>
      <goals>
        <goal>build-image</goal>
      </goals>
    </execution>
  </executions>
</plugin>

[snicoll]

It's indeed not possible to map a nested parameter unless we create a parameter for the sole purpose to be mapped. This is one of the downsides of using such structure with Maven plugins. I don't think we should expose the parameters and users should rather define a property that suits their needs using either the suggestion above, or using a profile.

[scottfrederick]

I don't think we should expose the parameters and users should rather define a property that suits their needs using either the suggestion above, or using a profile.

I agree with @snicoll, as Maven makes it simple enough to create your own properties and use them in the plugin configuration.

[wilkinsona]

I too agree with @snicoll. We've already seen some examples of users defining their own properties such as this from
#29756:

<configuration>
    <image>
        <name>${docker.image-name}</name>
    </image>
    <docker>
        <publishRegistry>
            <username>${docker.credentials.username}</username>
            <password>${docker.credentials.password}</password>
        </publishRegistry>
    </docker>
</configuration>

This feels like the right way to go to me.

[philwebb]

Thanks everyone. I'm going to repurpose this one as documentation issue.

[scottfrederick]

Closing in favor of #34517