Enabling Public Access To Development Machine

Click here for screencast and original post

open ssh tunnel from your local machine

For running Rails app in development, you can do this since rails s runs on port 3000.

localhost$ ssh -R 8088:localhost:3000 remote_server -N &

This creates a tunnel that binds remote TCP port 8088 to local TCP port 3000.

-R flag is for remote binding which tell the remote server to send TCP traffic on port 8088 to my machine. This is basically reverse of -L which binds the local machine’s port to remote.

8088: specifies the port on remote server. Therefore, following command on remote server will give a result assuming that I’m running a Rails app on port 3000.

remote_server$ curl localhost:8088

localhost is the host, obviously my local machine where the traffic will bind to.

:3000 is the local port you want to bind the traffic to.

-N tells ssh to not execute a remote command. Should always use this if we’re just tunneling.

& makes it run in background.

install socat if not installed on remote server

This is the definition from socat.

Socat is a command line based utility that establishes two bidirectional byte streams and transfers data

between them

For Ubuntu, remote_server$ sudo apt-get install socat will do.

run socat to relay public traffic

On remote server, expose a public port and then route the traffic to local port that’s bound to my local machine.

remote_server$ socat TCP-LISTEN:8090,fork,reuseaddr TCP-CONNECT:127.0.0.1:8088 &

TCP-LISTEN:8090,fork,reuseaddr tells socat to listen TCP on port 8090, creating a server at that port. The options are self-explanatory.

TCP-CONNECT:127.0.0.1:8088 tells socat to connect TCP to localhost at port 8088 which is bound to my machine.