Socks proxy to connect private hosts with circleci

circle.yml

machine: 
  services:
    - docker
  post:
    - wget https://gist.githubusercontent.com/gianrubio/dce37ee9b9c024937832d776597e2603/raw/4cdb30e5075e8e6064ac48a258e05f518f8c88c0/circleci-tunnel.sh ~/ && chmod +x ~/circleci-tunnel.sh
    - ~/circleci-tunnel.sh start:
        background: true

circleci-tunnel.sh

#!/bin/bash -x
set -e

function tunnel_up(){
    sudo apt-get install redsocks -y
    ssh -o StrictHostKeyChecking=no -v user@cmyhost -22 -i ~/.ssh/my-private-key  -D 9999 -nf "sleep 90000" &
    echo 'base{log_debug = on; log_info = on; log = "file:/tmp/reddi.log";daemon = on; redirector = iptables;}redsocks { local_ip = 127.0.0.1; local_port = 12345; ip = 127.0.0.1;port = 9999; type = socks5; }' > ~/redsocks.conf
    sudo redsocks -c ~/redsocks.conf &
    sudo iptables -t nat -N REDSOCKS
    sudo iptables -t nat -A REDSOCKS -p tcp -d 10.0.0.0/8 -j DNAT --to 127.0.0.1:12345
    sudo iptables -t nat -A OUTPUT -d 10.0.0.0/8 -j REDSOCKS
    sudo iptables -t nat -I PREROUTING 1 -d 10.0.0.0/8 -j REDSOCKS
}

if [ $1 == "start" ]; then
    tunnel_up
fi