public function build(string $imageName, $dockerfile = null) {

		if( $dockerfile === null )
			$dockerfile = 'Dockerfile';

		$this->requireProcess();

		$process = ProcessBuilder::create([
			'docker', 'build', '-f', $dockerfile, '-t', $imageName, '.'
		])
			->setTimeout(null)->getProcess();

		$this->processHelper->run($this->output, $process, null, null, OutputInterface::VERBOSITY_NORMAL);

		if($process->getExitCode() !== 0)
			throw new BuildFailedException($imageName, $dockerfile, 22);

	}