Create a UNIX socket connected to a TCP socket. Useful for connecting a rails app to a postgres instance that has been dockerized

unix-socket-to-tcp.sh

#!/bin/bash

set -e

if [ $# -ne 3 ]; then
    echo "Usage:"
    echo ""
    echo "    `basename $0` <unix socket file> <host> <listen port>"
    echo ""
    echo "For example:"
    echo ""
    echo "    `basename $0` /tmp/.s.PGSQL.5432 localhost 5432"
    echo ""
    echo "Will create a Unix socket at '/tmp/.s.PGSQL.5432' and connect it to TCP socket on 'localhost:5432'"
    echo ""
    exit
fi

SOCK=$1
HOST=$2
PORT=$3

socat -d -d -d -lf ${HOME}/tmp/socat.log UNIX-LISTEN:${SOCK},reuseaddr,fork TCP:${HOST}:${PORT}