Baseline Gradle Plugin

The Baseline Gradle plugin lets you verify that the OSGi semantic versioning rules are obeyed by your OSGi bundle.

When you run the baseline task, the plugin baselines the new bundle against the latest released non-snapshot bundle (i.e., the baseline). That is, it compares the public exported API of the new bundle with the baseline. If there are any changes, it uses the OSGi semantic versioning rules to calculate the minimum new version. If the new bundle has a lower version, errors are thrown.

The plugin has been successfully tested with Gradle 4.10.2.


To use the plugin, include it in your build script:

buildscript {
    dependencies {
        classpath group: "com.liferay", name: "com.liferay.gradle.plugins.baseline", version: "2.1.0"

    repositories {
        maven {
            url ""

apply plugin: "com.liferay.baseline"

The Baseline plugin automatically applies the java and reporting-base plugins.

Since the plugin needs to download the baseline, you have to configure a repository that hosts it; for example, the central Maven 2 repository:

repositories {

Project Extension

The Baseline plugin exposes the following properties through the baselineConfiguration extension:

Property NameTypeDefault ValueDescription
allowMavenLocalbooleanfalseWhether to let the baseline come from the local Maven cache (by default: ${user.home}/.m2). If the local Maven cache is not configured as a project repository, this property has no effect.
lowestBaselineVersionString"1.0.0"The greatest project version to ignore for the baseline check. If the project version is less than or equal to the value of this property, the baseline task is skipped.
lowestMajorVersionIntegerContent of the file ${project.projectDir}/.lfrbuild-lowest-major-version, where the default file name can be changed by setting the project property baseline.lowest.major.version.file.The lowest major version of the released artifact to use in the baseline check.
lowestMajorVersionRequiredbooleanfalseWhether to fail the build if the lowestMajorVersion is not specified.

If the lowestMajorVersion is not specified, the plugin runs the check using the most recent released non-snapshot bundle as baseline, which matches the version range (,${project.version}). Otherwise, if the lowestMajorVersion is equal to a value L and the project has version M.x.y (with L less or equal than M), multiple checks are performed in order, using the following version ranges as baseline:

  1. [L.0.0, (L + 1).0.0)
  2. [(L + 1).0.0, (L + 2).0.0)
  3. [(M - 2).0.0, (M - 1).0.0)
  4. [(M - 1).0.0, M.0.0)
  5. [M.0.0, M.x.y)

The first failing check fails the whole build.


The plugin adds one task to your project:

NameDepends OnTypeDescription
baselinejarBaselineTaskCompares the public API of this project with the public API of the previous released version, if found.

The baseline task is automatically configured with sensible defaults:

Property NameDefault Value
sourceDirThe first resources directory of the main source set (by default: src/main/resources).


Task Properties

Property NameTypeDefault ValueDescription
baselineConfigurationConfigurationnullThe configuration that contains exactly one dependency to the baseline bundle.
bndFileFilenullThe BND file of the project. If provided, the task will automatically update the Bundle-Version header.
forceCalculatedVersionbooleanfalseWhether to fail the baseline check if the Bundle-Version has been excessively increased.
ignoreExcessiveVersionIncreasesbooleanfalseWhether to ignore excessive package version increase warnings.
ignoreFailuresbooleanfalseWhether the build should not break when semantic versioning errors are found.
logFileFilenullThe file to which the results of the baseline check are written. (Read-only)
logFileNameString"baseline/${}.log"The name of the file to which the results of the baseline check are written. If the reporting-base plugin is applied, the file name is relative to reporting.baseDir; otherwise, it’s relative to the project directory.
newJarFileFilenullThe file of the new OSGi bundle.
reportDiffbooleantrue if the project property has either value "diff" or "persist"; false otherwiseWhether to show a granular, differential report of all changes that occurred in the exported packages of the OSGi bundle.
reportOnlyDirtyPackagesbooleanValue of the project property if specified; true otherwise.Whether to show only packages with API changes in the report.
sourceDirFilenullThe directory to which the packageinfo files are generated or updated.

The properties of type File support any type that can be resolved by project.file. Moreover, it is possible to use Closures and Callables as values for the String properties to defer evaluation until task execution.

Helper Tasks

If the lowestMajorVersion property is specified with a value L, the plugin creates a series of helper tasks of type BaselineTask at the end of the project evaluation, one for each major version between L and the major version M of the project:

  1. Task baseline${L + 1}, which depends on baseline${L + 2} and uses the version range [(L + 1).0.0, (L + 2).0.0) as baseline.
  2. Task baseline${L + 2}, which depends on baseline${L + 3} and uses the version range [(L + 2).0.0, (L + 3).0.0) as baseline.
  3. Task baseline${M - 2}, which depends on baseline${M - 1} and uses the version range [(M - 2).0.0, (M - 1).0.0) as baseline.
  4. Task baseline${M - 1}, which depends on baseline${M} and uses the version range [(M - 1).0.0, M.0.0) as baseline.
  5. Task baseline${M}, which uses the version range [M.0.0, M.x.y) as baseline.

The baseline task is also configured to use the version range [L.0.0, (L + 1).0.0) as baseline, and to depend on the task baseline${L + 1}. This means that running the baseline task runs the baseline check against multiple versions, starting from the most recent M and going back to L.

Moreover, all tasks except baseline${M} have the property ignoreExcessiveVersionIncreases set to true.

Additional Configuration

There are additional configurations that can help you baseline your OSGi bundle.

Baseline Dependency

The plugin creates a configuration called baseline with a default dependency to a released non-snapshot version of the bundle:

  • version range [L.0.0, (L + 1).0.0) if the lowestMajorVersion property is specified with a value L.
  • version range (,${project.version}) otherwise.

It is possible to override this setting and use a different version of the bundle as baseline.

System Properties

It is possible to set the default values of the ignoreFailures property for a BaselineTask task via system properties:


For example, run the following Bash command to execute the baseline check without breaking the build, in case of errors:

./gradlew baseline -Dbaseline.ignoreFailures=true
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