16 KiB
Scriptform Manual
This is the manual for version %%VERSION%%.
Table of Contents
Invocations
Upon starting Scriptform, it will change the working directory to the path containing the form definition you've sepcified. It will read the form definition and perform some basic sanity checks to see if, for instance, the scripts you specified exist and are executable.
There are multiple ways of running ScriptForm. This chapter outlines the various methods. They are listed in the order of least to most pruduction-ready.
Shell foreground
Sriptform can be run directly from the shell in the foreground with the -f
(--foreground
) option. This is most useful for testing and development:
$ /usr/bin/scriptform -p8000 -f ./formdef.json
Daemon
If you do not specify the -f
option, Scriptform will go into the background:
$ /usr/bin/scriptform -p8000 ./formdef.json
$
A pid file will be written in the current directory, or to the file specified
by --pid-file
. A log file will be written a .log file in the current
directory, or to the file specified by the --log-file
option.
To stop the daemon, invoke the command with the --stop
option. You must
specifiy at least the --pid-file
option, if the daemon was started with one.
$ /usr/bin/scriptform --pid-file /var/run/scriptform.pid --stop
Init script
An example init script is provided in the contrib directory. For the Debian
package, you can find it in /usr/share/doc/scriptform/
. To install it on
Debian-derived systems:
sudo cp /usr/share/doc/scriptform/scriptform.init.d_debian /etc/init.d/scriptform
sudo chmod 755 /etc/init.d/scriptform
sudo update-rc.d scriptform defaults
Then, edit the init script and set the FORM_CONFIG variable.
sudo vi /etc/init.d/scriptform
FORM_CONFIG="/usr/local/scriptform/myscript/myscript.json
Finally, start it:
sudo /etc/init.d/scriptform start
Behind Apache
Enable Apache modules mod_proxy and mod_proxy_http:
$ sudo a2enmod proxy
$ sudo a2enmod proxy_http
Configure:
Redirect permanent /scriptform /scriptform/
ProxyPass /scriptform/ http://localhost:8000/
ProxyPassReverse /scriptform/ http://localhost:8000/
Make sure the path ends in a slash! (That's what the redirect is for). Otherwise, you may encounter the following error:
+ TypeError: index() got an unexpected keyword argument 'form_name'
Form config (JSON) files
Forms are defined in JSON format. They are referred to as Form config files. A single JSON file may contain multiple forms. Scriptform will show them on an overview page, and the user can select which form they want to fill out.
Structurally, they are made up of the following elements:
-
title
: Text to show at the top of each page. Required, String. -
forms
: A list of dictionaries of form definitions. Required, List of dictionaries.-
name
: Name for the form. This must be unique. Required, String, Unique. -
title
: Title for the form. Required, String. -
description
: A description of the form. May include HTML tags. Required, String. -
submit_title
: The text on the submit button of the form. The default value is 'Submit
'. Optional, String. -
script
: The path to an executable script of binary that will be called if the form is submitted. See also Callbacks. When Scriptform starts, it switches to the directory containing the form definition. You should place your scripts there or otherwise specify full paths to the scripts. Required, String. -
output
: Determines how the output of the callback is handled. See the Output section. The default value is 'escaped
'. Optional, String. -
fields
: List of fields in the form. Each field is a dictionary. Required, List of dictionaries.-
name
: The name of the field. This is what is passed as an environment variable to the callback. Required, String. -
title
: The title for the field, shown just above the actual field. Required, String. -
type
: Field type. Supported types are: string, integer, float, date, radio, select, text, password and file. For more information, see Field types. -
required
: Whether the field is required. Optional, Boolean. -
...
: Other options, which depend on the type of field. Optional.
-
-
allowed_users
: A list of users that are allowed to view and submit this form. Optional, List of strings.
-
-
users
: A dictionary of users where the key is the username and the value is the plaintext password. This field is not required. Dictionary.
For example, here's a form config file that contains two forms:
{
"title": "Test server",
"forms": [
"name": "import",
"title": "Import data",
"description": "Import SQL into a database",
"submit_title": "Import",
"script": "job_import.sh",
"fields": [
{
"name": "target_db",
"title": "Database to import to",
"type": "select",
"options": [
["devtest", "Dev Test db"],
["prodtest", "Prod Test db"]
]
},
{
"name": "sql_file",
"title": "SQL file",
"type": "file"
}
]
},
{
"name": "add_user",
"title": "Add user",
"description": "Add a user to the htaccess file or change their password",
"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": "Password (Repear)",
"type": "password"
}
]
}
]
}
Many more examples can be found in the examples
directory in the source code.
Field types
String
The string
field type presents the user with a single line input field.
The string
field type supports the following additional options:
minlen
: The minimum allowed length for the field.maxlen
: The maximum allowed length for the field.
Integer
The integer
field type presents the user with an input box in wich they may
enter an integer number. Depending on the browser's support for HTML5 forms,
the input field may have spin-buttons to increase and decrease the value.
The integer
field type supports the following additional options:
min
: The minimum allowed value for the field.max
: The maximum allowed value for the field.
Float
The float
field type presents the user with an input box in which they enter
a Real number (fractions).
The float
field type supports the following additional options:
min
: The minimum allowed value for the field.max
: The maximum allowed value for the field.
Please note that some real numbers cannot be represented exactly by a computer and validation may thus be approximate. E.g. 0.499999999999999 will pass the test for a maximum value of 0.5.
Date
The date
field type presents the user with an input box in which they can
enter a date. Depending on the browser's support for HTML5 forms, the input
field may have a pop-out calendar from which the user can select a date.
The date must be entered, and will be passed to the callback, in the form YYYY-MM-DD.
The date
field type supports the following additional options:
min
: The minimum allowed date (format: a string YYYY-MM-DD)max
: The maximum allowed date (format: a string YYYY-MM-DD)
Radio
Select
Text
The text
field presents the user with a field in which they can enter
multi-lined text.
The text
field type supports the following additional options:
rows
: The number of rows to make the input fieldcols
: The number of cols to make the input filed.minlen
: The minimum allowed length for the field.maxlen
: The maximum allowed length for the field.
Password
minlen
: The minimum allowed length for the field.
File
The file
field type presents the user with a field through which they can
upload a file. Uploaded files are streamed to temporary files by Scriptform,
after which the original field value is replaced with this temporary file name.
This allows users to upload large files.
The original file name of the uploaded file is stored in a new variable '<field_name>__name'.
The file
field type supports the following additional options:
extensions
: A list of extensions (minus leading dot) that are accepted for file uploads. For example:"extensions": ["csv", "tsv"]
No additional validatikon is done on the file contents.
Output
All output is assumed to be UTF8, regardless of system encoding!
Output types
Scripts can have a few different output types. The output type is specified in
the output
field of the form definition. For example, the following form
definition has a raw
output type.:
{
"name": "display_image",
"title": "Show an image",
"description": "Show an image",
"script: "job_display_image.sh",
"output": "raw",
"fields": []
}
The following output types are supported:
-
escaped
: the output of the callback will have its HTML entities escaped and will be wrapped in PRE elements. This is the default option. -
html
: If the value ishtml
, the output will not be escaped or wrapped in PRE tags, and can thus include HTML markup. -
raw
: The output of the script is streamed directly to the client's browser. This allows you to output images, binary files, etc to the client. The script must include the proper headers and body itself. Examples of raw script output can be found in theexamples/raw
directory.
Exit codes
If the script's exit code is 0, the output of the script (stdout) is captured and shown to the user in the browser.
If a script's exit code is not 0, it is assumed an error occured. Scriptform will show the script's stderr output (in red) to the user instead of stdin.
Callbacks
Callbacks are called after the form has been submitted and its values have been validated. They are the actual implementations of the form's action.
A script callback can be any kind of executable, written in any kind of language. As long as it is executable, can read the environment and output things to stdout, it can be used as a callback.
Validation
Fields of the form are validated by Scriptform before the script is called. Exactly what is validated depends on the options specified in the Form Definition. For more info on that, see the Field Types section of this manual.
Field values
Field values are passed to the script in its environment. For instance, a form field definition:
{
"name": "ip_address",
"title": "IP Address",
"type": "string"
}
becomes available in a shell script as:
echo $ip_address
or in a Python script as:
import os
print os.environ['ip_address']
Uploaded files are streamed to temporary files by Scriptform. The name of the temporary file is then passed on as the field's value. For example, given the following field definition:
{
"name": "csv_file",
"title": "CSV file to import",
"type": "file"
}
The contents of the file is available in a shell script as:
echo $csv_file # output: /tmp/tmp_scriptform_Xu72bK
ROWS=$(wc -l $csv_file)
echo "The CSV file has $(expr $ROWS - 1) rows"
These temporary files are automatically cleaned up after the script's exeuction ends.
Examples of file uploads can be found in the examples/simple
and
examples/megacorp
directories.
Users
ScriptForm supports basic htauth user authentication. Users can be defined, and
form access can be limited to certain users. Users are defined in the users
top-level field of the form configuration file. For example, in the following
form configuration file, there are two users. Only user test2
is allowed to
view the form 'only_some_users'.
{
"title": "Authorization protected",
"users": {
"test": "2bb80d537b1da3e38bd30361aa855686bde0eacd7162fef6a25fe97bf527a25b",
"test2": "5e884898da28047151d0e56f8dc6292773603d0d6aabbdd62a11ef721d1542d8"
},
"forms": [
"name": "only_some_users",
"title": "Only some users",
"description": "You should only see this if you're user 'test2'",
"submit_title": "Do nothing",
"script": "job_do_nothing.sh",
"allowed_users": ["test2"],
"fields": []
}
]
}
Passwords
Passwords are unsalted SHA256 hashed passwords. To generate one, you can use
the --generate-pw
option of Scriptform. This will ask you twice for a
plaintext password and return the hash that can be used in the users
element.
$ ./scriptform.py --generate-pw
Password:
Repeat password:
ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad
Form definitions may specify which users are allowed to view, access and submit
the form. This is specified by a allowed_users
field in the form definition,
as can be seen in the previous form configuration example. Multiple users may
be specified.
Form limiting
You may specify a allowed_users
field in a form definition. Only user names
listed in the field are allowed to see and submit that form. If the user is not
listed, they won't even see the form as being available.
For an example, see the (beginning of this chapter)[#users].
Security considerations
- Passwords have no salt. This makes them slightly easier to bruteforce en-mass.
- Scriptform does not natively support secure HTTPS connections. This means usernames and passwords are transmitted over the line in nearly plaintext. If you wish to prevent this, you should put Scriptform behind a proxy that does support Scriptform, such as Apache. For more information on that, see the "Invocations" chapter.