Used Dante SOCKS server. It's installed at DigitalOcean(DO)
Docker Machine is used. Here is complete example how to run Docker container in DO droplet.
vimagick/dante Docker image is used. Only custom configuration is added in a dockerfile.
In the server used 'username' auth method: auth by system user.
So, to add a new user:
$ docker exec -it dante_dante_1 bash
>>> sudo useradd --shell /usr/sbin/nologin proxyuser
>>> sudo passwd proxyuser
>>> [enter pass twice]
>>> exit
$ curl -x socks5h://username:password@<your_DO_ip_address>:1984 https://www.youtube.com