Get the most recent tag from the current branch, which made by 'git tag -a master_1.2.3.123'

version.gradle

/*
 * Gets the version name from the latest Git tag
 */
def getVersionName = { ->
    def stdout = new ByteArrayOutputStream()
    exec {
        commandLine 'git', 'describe', '--tags'
        standardOutput = stdout
    }
    return stdout.toString().trim()
}

/*
 * Gets the short version name from the latest Git tag
 */
def getShortVersionName = { ->
    def stdout = new ByteArrayOutputStream()
    exec {
        commandLine 'git', 'describe', '--tags', '--abbrev=0'
        standardOutput = stdout
    }
    return stdout.toString().trim()
}

task version << {
    println getVersionName()
}

task shortVersion << {
    println getShortVersionName()
}

git describe --match git rev-parse --abbrev-ref HEAD* --tags

This command can exactly get the latest tag on the current branch even there are many tags in a same commit.