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Setup for an easy to use, simple reverse http tunnels with nginx and ssh. It's that simple there's no authentication at all.The end result, a single ssh command invocation gives you a public url for your web app hosted on your laptop.
#! /bin/sh
exec 3>&1
eval ssh -N -T $ssh_server -l $ssh_user -R 0:localhost:$local_port -p $ssh_port 2>&1 1>&3 \
| sed 's|^Allocated port \([[:digit:]]\+\) for remote forward to|Your url is '$url_tmpl' will be forwarded to|'
A lot of times you are developing a web application on your own laptop or home computer and would like to demo it to the public. Most of those times you are behind a router/firewall and you don't have a public IP address. Instead of configuring routers (often not possible), this solution gives you a public URL that's reverse tunnelled via ssh to your laptop.
Because of the relaxation of the sshd setup, it's best used on a dedicated virtual machine just for this (an Amazon micro instance for example).
Server side:
* a server with a public ip ( in this document)
* a domain name (domain.tld in this document)
* a wildcard dns entry in the domain pointing to the public ip (* 1800 IN A
* nginx
* sshd
Client side:
* ssh client (even plink would work on Windows)
Nginx config
A wildcard dns should point to this nginx instance.
Every `www<port>.domain.tld` will be proxied to `<port>`
Where `<port>` needs to be 4 or 5 digits.
server {
server_name "~^www(?<port>\d{4,5})\.domain\.tld$";
location / {
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header Host $host;
SSH configuration
A sshd configuration to allow a user with no password
and a forced command, so that the user can't get shell access.
Match User tunnel
# ChrootDirectory
ForceCommand /bin/echo do-not-send-commands
AllowTcpForwarding yes
PasswordAuthentication yes
PermitEmptyPasswords yes
PAM needs to be disabled if sshd is to allow login without a password.
That's not always possible, is not even smart. Another approach would be
a separate instance of sshd, on a different port, just for the tunnel user.
Make a copy of the config file, change/add these settings:
UsePAM no
AllowUsers tunnel
Port 722
And then run `sshd -f /etc/ssh/sshd_config_tunnel`.
The `tunnel` user has an empty password field in /etc/shaddow.
Just connect with:
ssh -N -T -l tunnel -R 0:localhost:5050 -p 722
ssh will respond with a `Allocated port 56889 for remote forward to localhost:5050` message.
Then you can use www56889.domain.tld
Test ChrootDirectory in sshd
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