Simple Docker SFTP server.

1. Install Docker.
2. You can change port 2222 to any in docker-compose.yml file.
3. You can change user ('foo') and password ('pass') to any in docker-compose.yml file.
4. Run:

docker-compose up -d

4. Connection example for PHP (on Windows):

$sftp = new SFTP('host.docker.internal', 2222);
$sftp->login('foo', 'pass')