GGG. Gradle, Groovy and Git. Slap this inside your Gradle-script and you've rolled your own git-plugin.

GitContext.groovy

class GitContext {    
    @Lazy String branchName = {
        def proc = 'git rev-parse --abbrev-ref HEAD'.execute()        
        proc.waitFor()
        assert proc.exitValue() == 0, proc.err.text

        return proc.in.text.trim()
    }()

    def boolean isMasterBranch() {
        return branchName == "master"
    }

    @Lazy String revision = { 
        def proc = 'git rev-parse --short HEAD'.execute()        
        proc.waitFor()
        assert proc.exitValue() == 0, proc.err.text

        return proc.in.text.trim()
    }()

    @Lazy String lastCommitter = { 
        def proc = 'git log -1 --format=%cE'.execute()
        proc.waitFor()
        assert proc.exitValue() == 0, proc.err.text

        return proc.in.text.trim()
    }()

}