SonarScanner for Gradle
The SonarScanner for Gradle provides an easy way to start the scan of a Gradle project.
The ability to execute the SonarScanner analysis via a regular Gradle task makes it available anywhere Gradle is available (developer build, CI server, etc.), without the need to manually download, setup, and maintain a SonarScanner CLI installation. The Gradle build already has much of the information needed for the SonarScanner to successfully analyze a project. By preconfiguring the analysis based on that information, the need for manual configuration is reduced significantly.
Prerequisites
- Gradle 7.3+
- Java 17
Bytecode created by javac
compilation is required for Java analysis, including Android projects.
See also the general requirements on the scanner environment.
Configure the scanner
Installation is automatic, but certain global properties should still be configured. A good place to configure global properties is ~/.gradle/gradle.properties
. Be aware that the scanner uses system properties so all properties should be prefixed by systemProp
.
# gradle.properties
systemProp.sonar.host.url=http://localhost:9000
Analyzing
First, you need to activate the scanner in your build. Kotlin DSL is the default choice for new Gradle builds.
Apply the SonarQube plugin dependency to your build.gradle.kts
file:
plugins {
id("org.sonarqube") version "versionNumber" // Replace with latest scanner version number
}
sonar {
properties {
property("sonar.projectKey", "myProjectKey")
property("sonar.organization", "myOrganization")
property("sonar.host.url", "myHostUrl")
}
}
If you use Groovy DSL, it is still supported for Gradle 2.1+. In that case, apply the SonarQube plugin dependency to your build.gradle
file:
plugins {
id "org.sonarqube" version "versionNumber" // Replace with latest scanner version number
}
sonar {
properties {
property "sonar.projectKey", "myProjectKey"
property "sonar.organization", "myOrganization"
property "sonar.host.url", "myHostUrl"
}
}
Ensure that you declare the plugins in the correct sequence required by Gradle, that is, after the buildscript block in your build.gradle
file. More details on Gradle - Plugin: org.sonarqube.
Assuming a local SonarQube server with out-of-the-box settings is up and running, no further configuration is required.
You need to pass an authentication token using one of the following options:
- Use the
sonar.token
property in your command line: Executegradle sonar -Dsonar.token=yourAuthenticationToken
and wait until the build has completed. - Create the
SONAR_TOKEN
environment variable and set the token as its value before you run the analysis.
Once passing your token and running an analysis, open the web page indicated at the bottom of the console output. Your analysis results should be available shortly after the CI-side analysis is complete.
Analyzing multi-project builds
To analyze a project hierarchy, apply the SonarQube plugin to the root project of the hierarchy. Typically (but not necessarily) this will be the root project of the Gradle build. Information pertaining to the analysis as a whole has to be configured in the sonar
block of this project. Any properties set on the command line also apply to this project.
A configuration shared between subprojects can be configured in a subprojects block.
// build.gradle
subprojects {
sonar {
properties {
property "sonar.sources", "src"
}
}
}
Project-specific information is configured in the sonar
block of the corresponding project.
// build.gradle
project(":project1") {
sonar {
properties {
property "sonar.branch.name", "Foo"
}
}}
To skip SonarScanner analysis for a particular subproject, set sonarqube.skipProject
to true.
// build.gradle
project(":project2") {
sonar {
isSkipProject = true
}
}
Task dependencies
All tasks that produce output that should be included in the SonarScanner analysis need to be executed before the sonar
task runs. Typically, these are compile tasks, test tasks, and code coverage tasks.
Starting with v3.0 of the SonarScanner for Gradle, task dependencies are no longer added automatically. Instead, the SonarScanner plugin enforces the correct order of tasks with mustRunAfter
. You need to be either manually run the tasks that produce output before sonarqube
, or you can add a dependency to the build script:
// build.gradle
project.tasks["sonar"].dependsOn "anotherTask"
Sample project
A simple working example is available at this URL so you can check everything is correctly configured in your env:
https://github.com/SonarSource/sonar-scanning-examples/tree/master/sonar-scanner-gradle/gradle-basic
Analysis property defaults
The SonarScanner for Gradle uses information contained in Gradle's object model to provide smart defaults for most of the standard analysis parameters, as listed below. Note that additional defaults are provided depending on the projects.
Gradle defaults for standard Sonar properties
Property | Gradle default |
---|---|
sonar.projectKey | [${project.group}:]${project.name} for root module; <root module key>:<module path> for submodules |
sonar.projectName | ${project.name} |
sonar.projectDescription | ${project.description} |
sonar.projectVersion | ${project.version} |
sonar.projectBaseDir | ${project.projectDir} |
sonar.working.directory | ${project.buildDir}/sonar |
Additional defaults for projects with Java-base or Java plugin applied
Property | Gradle default |
---|---|
sonar.sourceEncoding | ${project.compileJava.options.encoding} |
sonar.java.source | ${project.targetCompatibility} |
sonar.java.target | ${project.targetCompatibility} |
sonar.sources | ${sourceSets.main.allJava.srcDirs} (filtered to only include existing directories) |
sonar.tests | ${sourceSets.test.allJava.srcDirs} (filtered to only include existing directories) |
sonar.java.binaries | ${sourceSets.main.output.classesDir} |
sonar.java.libraries | ${sourceSets.main.compileClasspath} (filtering to only include files; rt.jar and jfxrt.jar added if necessary) |
sonar.java.test.binaries | ${sourceSets.test.output.classesDir} |
sonar.java.test.libraries | ${sourceSets.test.compileClasspath} (filtering to only include files; rt.jar and jfxrt.jar added if necessary) |
sonar.junit.reportPaths | ${test.testResultsDir} (if the directory exists) |
Additional default for Groovy projects
Property | Gradle default |
---|---|
sonar.groovy.binaries | ${sourceSets.main.output.classesDir} |
Additional defaults for Android projects
Additional defaults are provided for Android projects (com.android.application
, com.android.library
, or com.android.test
). By default the first variant of type debug
will be used to configure the analysis. You can override the name of the variant to be used using the parameter androidVariant
:
build.gradle
sonar {
androidVariant 'fullDebug'
}
Property | Gradle default |
---|---|
sonar.sources (for non test variants) | ${variant.sourcesets.map} (ManifestFile/CDirectories/AidlDirectories/AssetsDirectories/CppDirectories/JavaDirectories/RenderscriptDirectories/ResDirectories/ResourcesDirectories) |
sonar.tests (for test variants) | ${variant.sourcesets.map} (ManifestFile/CDirectories/AidlDirectories/AssetsDirectories/CppDirectories/JavaDirectories/RenderscriptDirectories/ResDirectories/ResourcesDirectories) |
sonar.java[.test].binaries | ${variant.destinationDir} |
sonar.java[.test].libraries | ${variant.javaCompile.classpath} + ${bootclasspath} |
sonar.java.source | ${variant.javaCompile.sourceCompatibility} |
sonar.java.target | ${variant.javaCompile.targetCompatibility} |
Passing manual properties / overriding defaults
The SonarScanner for Gradle adds a sonar
extension to the project and its subprojects, which allows you to configure/override the analysis properties.
// in build.gradle
sonar {
properties {
property "sonar.exclusions", "**/*Generated.java"
}
}
Sonar properties can also be set from the command line, or by setting a system property named exactly like the Sonar property in question. This can be useful when dealing with sensitive information (e.g. credentials), environment information, or for ad-hoc configuration.
gradle sonar -Dsonar.host.url=http://sonar.mycompany.com -Dsonar.verbose=true
While certainly useful at times, we recommend keeping the bulk of the configuration in a (versioned) build script, readily available to everyone. A Sonar property value set via a system property overrides any value set in a build script (for the same property). When analyzing a project hierarchy, values set via system properties apply to the root project of the analyzed hierarchy. Each system property starting with sonar.
will be taken into account.
Analyzing custom source sets
By default, the SonarScanner for Gradle passes on the project's main source set as production sources, and the project's test source set as test sources. This works regardless of the project's source directory layout. Additional source sets can be added as needed.
// build.gradle
sonar {
properties {
properties["sonar.sources"] += sourceSets.custom.allSource.srcDirs
properties["sonar.tests"] += sourceSets.integTest.allSource.srcDirs
}
}
Advanced topics
Self-signed certificate
If your SonarQube server is configured with HTTPS and a self-signed certificate then you must install the self-signed certificate into the Java truststore of your CI/CD host machine otherwise the scanner will not be able to connect to the server and the analysis will fail.
More on configuring SonarQube properties
Let's take a closer look at the sonar.properties
block. As we have already seen in the examples, the property
method allows you to set new properties or override existing ones. Furthermore, all properties that have been configured up to this point, including all properties preconfigured by Gradle, are available via the properties accessor.
Entries in the properties map can be read and written with the usual Groovy syntax. To facilitate their manipulation, values still have their “idiomatic” type (File, List, etc.). After the sonar.properties
block has been evaluated, values are converted to Strings as follows: Collection values are (recursively) converted to comma-separated Strings, and all other values are converted by calling their toString
methods.
Because the sonar.properties
block is evaluated lazily, properties of Gradle's object model can be safely referenced from within the block, without having to fear that they have not yet been set.
Troubleshooting
If you get a java.lang.OutOfMemoryError: Metaspace
Increase the metaspace size in your gradle.properties
file:
org.gradle.jvmargs=-XX:MetaspaceSize=512M -XX:MaxMetaspaceSize=512M
Task not found in root project
Sometimes Gradle has a difficult time seeing arguments as arguments and instead sees them as tasks to perform. When passing commands on Windows, this can be overcome by passing the parameters inside of quotation marks; use -D “key=value”
instead.
For example, the argument -D sonar.projectKey=<your-project>
should be passed as -D "sonar.projectKey=<your-project>"
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