stdiotunnel

stdiotunnel

Tunneling via stdin and stdout.

This project is useful for forwarding temporary port via docker exec.

Why not socat?, because socat cannot multiplex multiple connection with single stdio stream

example

create fifo by

mkfifo pipe1
mkfifo pipe2

run server by

./stdiotunnel server tcp::8081 < pipe1 > pipe2

open another terminal, and run client by

./stdiotunnel client tcp:127.0.0.1:8091 > pipe1 < pipe2

every request to :8081 will be forwarded to 127.0.0.1:8091

example forwarding ssh agent socket to container via docker exec

create fifo

mkfifo p1 p2

run client

./stdiotunnel client unix:$SSH_AUTH_SOCK < p1 > p2

open another terminal, and run server

docker exec -i <ctrid> sh -c 'rm -rf /tmp/ssh-agent; exec /stdiotunnel server unix:/tmp/ssh-agent' > p1 < p2

check if ssh agent works

docker exec <ctrid> sh -c 'export SSH_AUTH_SOCK=/tmp/ssh-agent; exec ssh-add -L'

KNOWN BUG

because this project using HTTP/2 protocol for multiplexing the connection, so it's limited to maximal stream available for single connection, see this