iamfirecracker / cl-clack-swank-ngrok

Hello world Clack application, with Swank and Ngrok running in the background for remote hacking

clack-swank-ngrok

Hello world Clack application, with Swank and Ngrok running in the background for remote hacking

Overview

• Clack Web application running on localhost:5000 (or 0.0.0.0:5000 when run inside Replit)
• Swank server running on localhost:4006
• Ngrok tunnel to expose localhost:4006 (i.e. the Swank server)

Instructions

Clone the repository:

$ cd ~/Workspace
$ git clone https://github.com/iamFIREcracker/cl-clack-swank-ngrok.git

Setup ADFS so it can load any system defined in this repository:

> (load "setup.lisp")

Quickload the main system:

> (ql:quickload "web")
To load "web":
  Load 1 ASDF system:
    web
; Loading "web"
..........
("web")

Call WEB:START:

> (web:start)
Hunchentoot server is started.
Listening on localhost:5000.
;; Swank started at port: 4006.
 <INFO> [10:13:43] ngrok setup.lisp (install-ngrok) -
  Ngrok already installed, changing authtoken
 <INFO> [10:13:44] ngrok setup.lisp (start) - Starting Ngrok on TCP port 4006
 <INFO> [10:13:44] ngrok setup.lisp (start) -
  Tunnnel established! Connect to the tcp://6.tcp.eu.ngrok.io:12321
"tcp://6.tcp.eu.ngrok.io:12321"

Note: the application will secure the Swank server by writing a user provided secret into ~/.slime-secret (watch out, it will overwrite whichever existing secret was previously stored there!); by default, the secret is read from the SLIME_SECRET environment variable, but if such variable were missing, the application will prompt the user to provide a value at run time. Similarly, the value of the NGROK_AUTH_TOKEN environment variable is used to tell Ngrok the account the newly created tunnel should be associated with, and again, should that variable not exist, the user will be asked to provide a value when WEB:START is called.

> (web:start)
SLIME_SECRET=my-secret-secret
NGROK_AUTH_TOKEN=auth-for-the-win
Hunchentoot server is started.
...

Note: in case you did not want / need Ngrok to run (say because you have SSH access to the server the application is running on, and you prefer to connect to the Swank server with an SSH tunnel instead), then all you have to do is pass :dont-ngrok t to WEB:START:

> (web:start :dont-ngrok t)
Hunchentoot server is started.
Listening on localhost:5000.
;; Swank started at port: 4006.

Test the Web server:

$ curl https://localhost:5000
Hello, Clack!

Open Vim/Emacs, connect to the Swank server (i.e. host: 6.tcp.eu.ngrok.io, port: 12321), and change the Web handler to return something different:

> (defun app (env)
    (declare (ignore env))
    '(200 (:content-type "text/plain") ("Hello, Matteo!")))
APP

Hit the Web server again, and this time it should return a different message:

$ curl https://localhost:5000
Hello, Matteo!

To stop the application (and the Swank server, and the Ngrok tunnel) simply call the STOP function:

> (web:stop)

See also

• ASDF: Another System Definition Facility
• Clack: Web Application Environment for Common Lisp
• SLIME: the Superior Lisp Interaction Mode for Emacs
• ngrok: (WIP) Common Lisp wrapper for installing and running Ngrok.