When using Maven with a multi-module project I can simply add the Sonar plugin to the parent POM:
<plugin>
<groupId>org.sonarsource.scanner.maven</groupId>
<artifactId>sonar-maven-plugin</artifactId>
<version>3.4.0.905</version>
</plugin>
And then run it in the project root to get aggregated results:
.../project$ mvn sonar:sonar
Or for a specific module:
.../project$ mvn sonar:sonar -f module/pom.xml
However this doesn't seem possible with Gradle.
If I only apply the SonarQube plugin (apply plugin: 'org.sonarqube') in the root project, I get aggregated results when running it in the root project, but the plugin is not available in the subprojects:
.../project$ ./gradlew :module:sonarqube
FAILURE: Build failed with an exception.
* What went wrong:
Task 'sonarqube' not found in project ':module'.
...
If I only apply the SonarQube plugin in the subprojects, running it on the root project doesn't give aggregated results.
If I apply the SonarQube plugin in allprojects (root project + subprojects), trying to run any Gradle command outputs:
FAILURE: Build failed with an exception.
* Where:
Build file '.../project/build.gradle' line: 38
* What went wrong:
A problem occurred evaluating root project 'project'.
> Failed to apply plugin [id 'org.sonarqube']
> Cannot add extension with name 'sonarqube', as there is an extension already registered with that name.
Is there a way to make the SonarQube plugin for Gradle to work in both root project and subprojects like it does for Maven?