Automatic versioning of Android build using git describe with Gradle

Question

I have searched extensively, but likely due to the newness of Android Studio and Gradle. I haven\'t found any description of how to do this. I want to do basically exactly

Answer 1

Based on Léo Lam's answer and my earlier explorations on the same solution for ant, I have devised a purely cross-platform solution using jgit:

(original source)

File: git-version.gradle

buildscript {
    dependencies {
        //noinspection GradleDynamicVersion
        classpath "org.eclipse.jgit:org.eclipse.jgit:4.1.1.+"
    }
    repositories {
        jcenter()
    }
}
import org.eclipse.jgit.api.Git
import org.eclipse.jgit.revwalk.RevWalk
import org.eclipse.jgit.storage.file.FileRepositoryBuilder

import static org.eclipse.jgit.lib.Constants.MASTER

def git = Git.wrap(new FileRepositoryBuilder()
        .readEnvironment()
        .findGitDir()
        .build())

ext.readVersionCode = {
    def repo = git.getRepository()
    def walk = new RevWalk(repo)
    walk.withCloseable {
        def head = walk.parseCommit(repo.getRef(MASTER).getObjectId())
        def count = 0
        while (head != null) {
            count++
            def parents = head.getParents()
            if (parents != null && parents.length > 0) {
                head = walk.parseCommit(parents[0])
            } else {
                head = null
            }
        }
        walk.dispose()
        println("using version name: $count")
        return count
    }
}

ext.readVersionName = {
    def tag = git.describe().setLong(false).call()
    def clean = git.status().call().isClean()
    def version = tag + (clean ? '' : '-dirty')
    println("using version code: $version")
    return version
}

The usage will be:

apply from: 'git-version.gradle'

android {
  ...
  defaultConfig {
    ...
    versionCode readVersionCode()
    versionName readVersionName()
    ...
  }
  ...
}