Shell In A Box

#console #lang-c #ssh #web 

Shell In A Box emulates a terminal in your browser. It implements a web server that works with purely JavaScript and CSS across most modern web browsers. This is helpful if you are e.g. behind a corporate firewall that blocks port 22, which is usually used for SSH connections.

License

Shell In A Box is released under the GNU General Public License version 2.

Prerequisites

Your page’s URL needs to be set up:

[isabell@stardust ~]$ uberspace web domain list
isabell.uber.space
[isabell@stardust ~]$

Installation

Clone Github project

Clone the shellinabox repository from Github into ~/shellinabox and cd into the newly created directory:

[isabell@stardust ~]$ git clone https://github.com/shellinabox/shellinabox
Cloning into 'shellinabox'...
remote: Enumerating objects: 3073, done.
remote: Total 3073 (delta 0), reused 0 (delta 0), pack-reused 3073
Receiving objects: 100% (3073/3073), 4.31 MiB | 6.47 MiB/s, done.
Resolving deltas: 100% (2418/2418), done.
[isabell@stardust ~]$ cd ~/shellinabox
[isabell@stardust shellinabox]$

Build executable

Run the autotools, afterwards build the application with configure followed by make:

[isabell@stardust shellinabox]$ autoreconf --install
[...]
Makefile.am: installing './INSTALL'
Makefile.am: installing './depcomp'
[isabell@stardust shellinabox]$ ./configure --prefix=$HOME
[...]
config.status: creating Makefile
config.status: creating config.h
config.status: executing depfiles commands
config.status: executing libtool commands
[isabell@stardust shellinabox]$ make
[...]
make[1]: Leaving directory '/home/isabell/shellinabox'
[isabell@stardust shellinabox]$ make install
[...]
make[1]: Leaving directory `/home/isabell/shellinabox'

This will create a new executable file named shellinaboxd (notice the d at the end of the filename) in your ~/bin directory.

Configuration

Configure web backend

Note

shellinabox is running on port 4200 by default.

To make the application accessible from the outside, configure a web backend:

[isabell@stardust ~]$ uberspace web backend set / --http --port <port>
Set backend for / to port <port>; please make sure something is listening!
You can always check the status of your backend using "uberspace web backend list".
[isabell@stardust ~]$

Setup daemon

To run shellinabox as a daemon, create a new file ~/etc/services.d/shellinabox.ini with the following content:

[program:shellinabox]
command=shellinaboxd --disable-ssl --verbose
autostart=yes
autorestart=yes

We are using two command-line options here:

  • --disable-ssl: Disables the built-in SSL functionality, since this is already enforced by Uberspace’s HTTPS configuration

  • --verbose: Enables verbose logging which helps troubleshooting (you can safely disable this if you want to)

You can find the full reference of command-line options on Google Code.

Refresh supervisord

After creating the configuration, tell supervisord to refresh its configuration and start the service:

[isabell@stardust ~]$ supervisorctl reread
SERVICE: available
[isabell@stardust ~]$ supervisorctl update
SERVICE: added process group
[isabell@stardust ~]$ supervisorctl status
SERVICE                            RUNNING   pid 26020, uptime 0:03:14
[isabell@stardust ~]$

Finishing installation

Point your browser to https://isabell.uber.space/ (replace isabell with your username) and enjoy your new browser-based shell.

Acknowledgements

The icon is made by Freepik from Flaticon.

Tested with shellinabox 2.20, Uberspace 7.6.1.2

Written by: lk3de <web-uberlab@lk3.de>