Access Maven settings.xml in pom.xml for Spring Boot Maven Plugin

Question

I would like to access the user-specific settings (passwords, usernames etc. for a shared private repository) that are contained within the settings.xml in my pom.

I need these settings for the Spring Boot Maven Plugin, because I want to use the publish feature there (pushing a created docker image to our private docker repository).

Is there a way to achieve this?

Of course I don't want to save any user-specific passwords inside the pom.xml.

The maven documentation states that it is possible to access the settings.xml (e.g. here: https://maven.apache.org/guides/getting-started/index.html#how-do-i-filter-resource-files), but it does not explain how to to that.

I expecting something like this in my pom:

<someTag>${userSettings.some.property}</someTag>

Answer 1

Suppose we have following configuration for spring-boot-maven-plugin

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <configuration>
        <image>
            <name>docker.example.com/library/${project.artifactId}</name>
            <publish>true</publish>
        </image>
        <docker>
            <publishRegistry>
                <username>user</username>
                <password>secret</password>
                <url>https://docker.example.com/v1/</url>
                <email>[email protected]</email>
            </publishRegistry>
        </docker>
    </configuration>
</plugin>

and do not want to store our credentials in pom.xml since it is available to everyone who has access to version control system. Maven way is to define profile in ~/.m2/setting.xml with our credentials and and replace credentials in pom.xml with corresponding placeholders, like:

~/.m2/settings.xml:

...
<profiles>
...    
    <profile>
        <id>registry-example.com</id>
        <properties>
            <registry.username>user</registry.username>
            <registry.password>secret</registry.password>
            <registry.url>https://docker.example.com/v1/</registry.url>
            <registry.email>[email protected]</registry.email>
        </properties>
    </profile>
...    
</profiles>
...

pom.xml:

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <configuration>
        <image>
            <name>docker.example.com/library/${project.artifactId}</name>
            <publish>true</publish>
        </image>
        <docker>
            <publishRegistry>
                <username>${registry.username}</username>
                <password>${registry.password}</password>
                <url>${registry.url}</url>
                <email>${registry.email}</email>
            </publishRegistry>
        </docker>
    </configuration>
</plugin>

Now, in order to tell maven to take into account the profile we have created we need to run maven with -P flag specifying id of our profile:

mvn spring-boot:build-image -Pregistry-example.com