Twig Filter - git commit/branch

Git.php

<?php 

namespace App\Twig\Extension;

class GitExtension extends \Twig_Extension
{
    public function getFilters()
    {
        return array(
            new \Twig_SimpleFilter('gitVersion', array($this, 'showCustomGitVersion')),
        );
    }

	/**
	 * Get current git version
	 */
	public function showCustomGitVersion()
	{
         $hash = exec('git rev-parse --short HEAD');
         $branch = exec('git rev-parse --abbrev-ref HEAD');
         $tag = exec('git describe');
         return $tag. ' ' . $hash . ' on '.$branch;
	}

    /**
     * {@inheritdoc}
     */
    public function getName()
    {
        return 'twig_git';
    }
}

Usage: version: {{ ''|showCustomGitVersion() }}