# Scriptform Manual This is the manual for version %%VERSION%%. ## Table of Contents 1. [Invocations](#invocations) - [Shell foreground](#invocations_foreground) - [Daemon](#invocations_daemon) - [Init script](#invocations_init) - [Behind Apache](#invocations_apache) 1. [Form config (JSON) files](#form_config) 1. [Field types](#field_types) - [String](#field_types_string) - [Integer](#field_types_integer) - [Float](#field_types_float) - [Date](#field_types_date) - [Radio](#field_types_radio) - [Checkbox](#field_types_checkbox) - [Select](#field_types_select) - [Text](#field_types_text) - [Password](#field_types_password) - [File](#field_types_file) 1. [Output](#output) - [Output types](#output_types) - [Exit codes](#output_exitcodes) - [Serving static files](#output_static_files) 1. [Script execution](#script_execution) - [Validation](#script_validation) - [Field Values](#script_fieldvalues) 1. [Users](#users) - [Passwords](#users_passwords) - [Form limiting](#users_formlimit) - [Security considerations](#users_security) 1. [Form customization](#cust) - [Custom CSS](#cust_css) 1. [Security](#security) ## 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**. - **`static_dir`**: Path to a directory from which static files should be served. See also "[Serving static files](#output_static_files)". **Optional**, **String**. - **`custom_css`**: Path to a file containing custom CSS. It will be included in every page's header. See also "[Form customization](#cust)". **Optional**, **String**. - **`forms`**: A list of dictionaries of form definitions. **Required**, **List of dictionaries**. - **`name`**: Name for the form. This must be unique. It is used internally by Scriptform to refer to forms. **Required**, **String**, **Unique**. - **`title`**: Title for the form. This is shown in the list of available forms and on the form page itself as the title for the form and as the caption for the button which takes you to the form. **Required**, **String**. - **`description`**: A description of the form. May include HTML tags. This is shown in the list of available forms and on the form page itself. **Required**, **String**. - **`script`**: The path to an executable script of binary that will be called if the form is submitted. See also [Callbacks](#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**. - **`submit_title`**: The text on the submit button of the form. **Optional**, **String**, **Default:** `Submit`. - **`output`**: Determines how the output of the callback is handled. See the [Output](#output) section. The default value is '`escaped`'. **Optional**, **String**, **Default:** `escaped`. - **`allowed_users`**: A list of users that are allowed to view and submit this form. **Optional**, **List of strings**. - **`hidden`**: If 'true', don't show the form in the list. You can still view it, if you know its name. This is useful for other forms to redirect to this forms and such. - **`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*, *checkbox*, *select*, *text*, *password* and *file*. For more information, see [Field types](#field_types). - **`required`**: Whether the field is required. **Optional**, **Boolean**, **Default:** `false`. - **`hidden`**: If 'true', the input field is hidden. This is useful for pre-filled forms which takes it values from the GET request. **Optional**, **boolean**, **Default:** `false`. - **`style`**: A string of inline CSS which will be applied to the field. **Optional**, **String**. - **`...`**: Other options, which depend on the type of field. For more information, see [Field types](#field_types). **Optional**. - **`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. - **`size`**: The size (in characters) of the input 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 ### Checkbox The `checkbox` field type represents the user with a toggleble checkbox that can be either 'on' or 'off'. If the checkbox was checked, the value '`on`' is passed to the script. Otherwise, '`off`' is passed. Unlike HTML forms, which send no value to the server if the checkbox was not checked, Scriptform always sends either 'on' or 'off'. ### 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 field - **`cols`**: 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 Scriptform uses the output of the script (stdout, stderr) to display something back to the user executing the script. 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 is `html`, 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 the `examples/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. ### Serving static files Scriptform can serve static files. It is disabled by default. To enable it, provide a `static_dir` option in the top section of the form configuration: { "title": "Static serve", "static_dir": "static", "forms": [ ... This tells Scriptform to serve static files from that location. To refer to a static file, use the `/static` URL: https://example.com/static?fname=foobar.png Will refer to the `static/foobar.png` file. If `static_dir` is a relative path, it will be relative to the form configuration (.json) file you're running. Scriptform does not provide the browser with a content-type of the file, since it is impossible to guess. Generally, browsers do a decent job at figuring it out themselves. ## Script execution When the user submits the form, scriptform will validate the provided values. If they check out, the specified script for the form will be executed. A script can be any kind of executable, written in any kind of language, including scripting languages. As long as it is executable, can read the environment and output things to stdout it is usable. Scippts written in scripting languages should include the shebang line that indicates which interpreter it should use: #!/usr/bin/php ### Validation Fields of the form are validated by the Scriptform backend before the script is called. If you have a HTML5 capable browser, the form will also be validated in the browser before you submit it. 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. Form validation is somewhat limited. For example, you can force a string's minimum and maximum length, but you cannot do more advanced validation such as checking if it starts with a certain value. If you wish to do that, you will have to do the validation in the script callback for a form. ### 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 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 HTTPS, such as Apache. For more information on that, see the "Invocations" chapter. ## Form customization ### Custom CSS You can customize a form input field's style using the **`style`** property of the field definition in the form configuration. It takes a string that will be put in the generated form's `style=""` HTML attribute. For example: "fields": [ { "name": "background", "title": "Different background color", "type": "string", "style": "background-color: #C0FFC0;" } ] The example above will render as: You can also include a global piece of CSS by specifying the **`custom_css`** property in the form definition. For example: { "title": "Customized forms", "custom_css": "custom.css", "forms": [ ... `custom.css` is the path to a file which will be included in the rendered HTML page in the `