1. Add Step Server Key

$ ls -l keys
total 4
-rw-------. 1 ikasamak ikasamak 1692 Mar 18 21:38 id_rsa

2. Make .env

$ cp .env.sample .env
$ vim .env

STEP_SERVER=stepserver.example.com
STEP_SERVER_USER=root
INPUT_KEY_FILENAME=id_rsa
LOCAL_PORT=1080

3. Start container

$ docker-compose up -d

4. Edit proxy.pac

$ vim proxy.pac

function FindProxyForURL(url, host) {
  if (shExpMatch(host, "example.com")) {
    return "SOCKS5 localhost:1080; DIRECT";
  } else {
    return "DIRECT";
  }
}

5. Browser setting