Create sockd.conf file locally on the docker host machine and map it with -v option of docker run.
Run socks server
docker run -d -p 1080:1080 -v /etc/sockd.conf:/etc/sockd.conf --name socks-server vimagick/dante
Add user
docker exec -it socks-server /bin/bash
useradd proxy_user
echo proxy_user:proxy_password | chpasswd
Use the Socks proxy server from a cURL command
curl -vvv -x socks5h://proxy_user:proxy_password@localhost:1080 https://example.com