ScriptForm

About

A stand-alone webserver that automatically generates forms from JSON to serve as frontends to scripts.

ScriptForm takes a JSON file which contains form definitions. It then constructs web forms from this JSON and serves these to users over HTTP. The user can select a form and fill it out. When the user submits the form, it is validated and the associated script is called. Data entered in the form is passed to the script through the environment.

Features

• Very rapidly construct forms with backends.
• Completely standalone HTTP server; only requires Python.
• Callbacks to any kind of script / program that supports environment variables.
• User authentication support through Basic HTAuth.
• Validates form values before calling scripts.
• Uploaded files are automatically saved to temporary files, which are passed on to the callback.
• Multiple forms in a single JSON definition file.
• Scripts can produce normal output, HTML output or stream their own HTTP response to the client. The last one lets you stream images or binaries to the browser.

Use-cases

Scriptform is very flexible and as such serves many use-cases. Most of these revolve around giving non-technical users a user friendly way to safely run scripts on a server.

Here are some of the potential uses of Scriptform:

• Add / remove users from htpasswd files.
• Execute SQL snippets.
• View service status
• Upload data to be processed.
• Restart, enable and disable services.
• Trigger for batch processing.

Example

The following example lets you add new users to a htpasswd file via ScriptForm. It presents the user with a form to enter the user's details. When the form is submitted, the job_add_user.sh script is called which adds the user to the htpasswd file.

Form configuration file: test_server.json

{
  "title": "Test server",
  "forms": [
      "name": "add_user",
      "title": "Add user",
      "description": "Add a user to the htpasswd file",
      "submit_title": "Add user",
      "script": "job_add_user.sh",
      "fields": [
        {"name": "username", "title": "Username", "type": "string"},
        {"name": "password1", "title": "Password", "type": "password"},
        {"name": "password2", "title": "Repeat password", "type": "password"}
      ]
    }
  ]
}

The script job_add_user.sh:

#!/bin/sh

if [ -z "$password1" ]; then
    echo "Empty password specified" >&2; exit 1
fi
if [ "$password1" != "$password2" ]; then
    echo "Passwords do not match" >&2; exit 1
fi

htpasswd -s -b .htpasswd $username $password1 || exit $?

echo "User created or password updated"

Set some rights and create the initial htpasswd file:

$ chmod 755 job_add_user.sh
$ touch .htpasswd

We can now start ScriptForm to start serving the form over HTTP. By default it starts as a daemon, so we specify the -f option to start it in the foreground instead.

$ scriptform -f -p8080 ./test_server.json

The user is presented with the following form:

When submitting the form, the results are displayed.

For more examples, see the examples directory

For more screenshots, see the screenshots Wiki page

Installation

Requirements

ScriptForm requires:

• Python 2.6+

No other libraries are required. Python v2.6+ is generally available by default on almost every major linux distribution. For other platforms Python is almost certainly available.

Usage

Usage:

Usage: ./scriptform.py [option] (--start|--stop) <form_definition.json>
       ./scriptform.py --generate-pw

Options:
  -h, --help            show this help message and exit
  -g, --generate-pw     Generate password
  -p PORT, --port=PORT  Port to listen on
  -f, --foreground      Run in foreground (debugging)
  --pid-file=PID_FILE   Pid file
  --log-file=LOG_FILE   Log file
  --start               Start daemon
  --stop                Stop daemon

ScriptForm can run both in daemon mode or in the foreground. In daemon mode, we can control ScriptForm with the --start and --stop options. By default it runs on port 80, which we can change with the -p option.

$ ./scriptform -p8000 ./test_server.json

This puts ScriptForm in the background as a daemon. It creates a PID file and a log file.

$ tail scriptform.py.log
2015-04-08 07:57:27,160:DAEMON:INFO:Starting
2015-04-08 07:57:27,161:DAEMON:INFO:PID = 5614
2015-04-08 07:57:27,162:SCRIPTFORM:INFO:Listening on 0.0.0.0:8000

In order to stop the daemon:

$ ./scriptform --stop

We can control the location of the PID file and log file with the --pid-file and --log-file options. If we don't specify these, ScriptForm will create them in the local directory.

To run ScriptForm in the foreground, specify the -f option.

If you're going to use basic authentication, you can generate a password for your user with the --generate-pw option:

$ ./scriptform.py --generate-pw
Password: 
Repeat password: 
2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae

You can paste the generated password into the password field. For more information, see the User Manual.

Security

ScriptForm is only as secure as you write your scripts. Although form values are validated before calling scripts, many possible security problems should be taken into consideration. As such, you should never expose ScriptForm to the public internet. Its intended end users should be people you trust at least to a certain degree.

License

ScriptForm is released under the MIT license.

Copyright (c) 20152 Ferry Boneder (ferry.boender@gmail.com)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.