The gradle plugin 'semver-git' sets the project.version based on annotated git tags. Version numbers must follow Semantic Versioning 2.0.0, with the syntax major.minor.patch.

In your build.gradle file:

plugins {
    id "com.cinnober.gradle.semver-git" version "2.2.0" apply false
}
// optionally: ext.nextVersion = "major", "minor" (default), "patch" or e.g. "3.0.0-rc2"
// optionally: ext.snapshotSuffix = "SNAPSHOT" (default) or a pattern, e.g. "<count>.g<sha><dirty>-SNAPSHOT"
// optionally: ext.dirtyMarker = "-dirty" (default) replaces <dirty> in snapshotSuffix
// optionally: ext.gitDescribeArgs = '--match *[0-9].[0-9]*.[0-9]*' (default) or other arguments for git describe.
// optionally: ext.semverPrefix = 'v' if your tags are named like v3.0.0
apply plugin: 'com.cinnober.gradle.semver-git'

Note: Use apply false combined with a manual apply if you want to change nextVersion and snapshotSuffix.

Then everything should just work. To create a release, create an annotated git tag, e.g.:

git tag -a 1.0.0 -m "New release"
git push --tags

When standing on an annotated tag commit, then version is simply the same as the tag (1.0.0 in this example). After a few commits git describe will show something like 1.0.0-5-g5242341 in which case the version is the snapshot of the next version. In this example the next version is minor, and the version will be 1.1.0-SNAPSHOT.

The snapshot suffix pattern can contain <count> and <sha> which will be replaced with the commit count (5) and the commit sha (5242341) respectively. For example the snapshot suffix <count>.g<sha> will generate the version 1.1.0-5.g5242341, i.e. a non-snapshot pre-release. For example the snapshot suffix pattern is <count>.g<sha>-SNAPSHOT which will generate the version 1.1.0-5.g5242341-SNAPSHOT, which is a unique snapshot version.

Versions are stored as annotated tags in git. Semantic versioning is used.

To create a new release, e.g. 1.2.3:

git tag -a 1.2.3 -m "New release"
git push --tags

If changes are made after version 1.2.3 then the version number be '1.3.0-SNAPSHOT' (default a minor change).

To upload the archives to the Maven Central (through the OSSRH), run:

gradle clean build uploadArchives

To upload the plugin to the Gradle Plugin Portal, run:

gradle clean build publishPlugins

Note that credentials are required for uploads. They should be placed in e.g. your ~/.gradle/gradle.properties for uploadArchives. See gradle.properties for more information.