view doc/xmlrpc.txt @ 7853:03c1b7ae3a68

issue2551328/issue2551264 unneeded next link and total_count incorrect Fix: issue2551328 - REST results show next link if number of results is a multiple of page size. (Found by members of team 3 in the UMass-Boston CS682 Spring 2024 class.) issue2551264 - REST X-Total-Count header and @total_size count incorrect when paginated These issues arose because we retrieved the exact number of rows from the database as requested by the user using the @page_size parameter. With this changeset, we retrieve up to 10 million + 1 rows from the database. If the total number of rows exceeds 10 million, we set the total_count indicators to -1 as an invalid size. (The max number of requested rows (default 10 million +1) can be modified by the admin through interfaces.py.) By retrieving more data than necessary, we can calculate the total count by adding @page_index*@page_size to the number of rows returned by the query. Furthermore, since we return more than @page_size rows, we can determine the existence of a row at @page_size+1 and use that information to determine if a next link should be provided. Previously, a next link was returned if @page_size rows were retrieved. This change does not guarantee that the user will get @page_size rows returned. Access policy filtering occurs after the rows are returned, and discards rows inaccessible by the user. Using the current @page_index/@page_size it would be difficult to have the roundup code refetch data and make sure that a full @page_size set of rows is returned. E.G. @page_size=100 and 5 of them are dropped due to access restrictions. We then fetch 10 items and add items 1-4 and 6 (5 is inaccessible). There is no way to calculate the new database offset at: @page_index*@page_size + 6 from the URL. We would need to add an @page_offset=6 or something. This could work since the client isn't adding 1 to @page_index to get the next page. Thanks to HATEOAS, the client just uses the 'next' url. But I am not going to cross that bridge without a concrete use case. This can also be handled client side by merging a short response with the next response and re-paginating client side. Also added extra index markers to the docs to highlight use of interfaces.py.
author John Rouillard <rouilj@ieee.org>
date Mon, 01 Apr 2024 09:57:16 -0400
parents e34b69d75ff7
children 57325fea9982
line wrap: on
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.. meta::
    :description:
        Documentation on the XMLRPC interface to the Roundup Issue
	Tracker. Includes sample clients.

.. index:: triple: api; xml; remote procedure call
   pair: api; xmlrpc

=========================
XML-RPC access to Roundup
=========================

.. contents::
   :local:

Introduction
============

Version 1.4 of Roundup includes an XML-RPC frontend for remote access. The
XML-RPC interface allows a limited subset of commands similar to those found in
local `roundup-admin` tool.

By default XML-RPC is accessible from ``/xmlrpc`` endpoint:

    http://username:password@localhost:8000/xmlrpc

For demo tracker the URL would be:

    http://localhost:8917/demo/xmlrpc

Enabling XML-RPC
================
There are two ways to run the XML-RPC interface:

  through roundup itself

  stand alone roundup-xmlrpc-server


Through Roundup
---------------

The XML-RPC service is available from the roundup HTTP server under
/xmlrpc.

To enable this set ``enable_xmlrpc`` to ``yes`` in the ``[web]``
section of the ``config.ini`` file in your tracker.

Each user that needs access must include the "Xmlrpc Access" role. To
add this new permission to the "User" role you should change your
schema.py to add::

    db.security.addPermissionToRole('User', 'Xmlrpc Access')

This is usually included near where other permissions like "Web Access"
or "Email Access" are assigned.

Standalone roundup-xmlrpc-server
--------------------------------

Using Roundup to access the xmlrpc interface is preferred. Roundup
provides better control over who can use the interface.

The Roundup XML-RPC standalone server must be started before remote
clients can access the tracker via XML-RPC. ``roundup-xmlrpc-server``
is installed in the scripts directory alongside ``roundup-server`` and
``roundup-admin``. When invoked, the location of the tracker instance
must be specified.

	roundup-xmlrpc-server -i ``/path/to/tracker``

The default port is ``8000``. An alternative port can be specified with the
``--port`` switch.

Security Consideration
======================

Both the standalone and embedded roundup XML endpoints used the
default python XML parser. This parser is know to have security
issues. For details see: https://pypi.org/project/defusedxml/.
You may wish to use the rest interface which doesn't have the same
issues. Patches with tests to roundup to use defusedxml are welcome.

.. caution::

   The current standalone ``roundup-xmlrpc-server`` implementation
   does not support SSL. This means that usernames and passwords will
   be passed in cleartext unless the server is proxied behind
   another server (such as Apache or lighttpd) that provides SSL.

Rate Limiting Failed Logins
---------------------------

See the `rest documentation
<rest.html#rate-limiting-api-failed-logins>`_ for rate limiting failed
logins on the API. There is no login rate limiting for the standalone
roundup-xmlrpc-server. Login rate limiting is only for the ``/xmlrpc``
endpoint when the Roundup server is used.

The XML-RPC uses the same method as the REST API.
Rate limiting is shared between the XMLRPC and REST APIs.

Client API
==========
The server currently implements seven methods/commands. Each method
requires that the user provide a username and password in the HTTP
authorization header in order to authenticate the request against the
tracker.

.. table::
   :class: valign-top

   ======= ===================================================================
   Command  Description
   ======= ===================================================================
   schema  Fetch tracker schema.

   list    arguments: *classname, [property_name]*

	   List all elements of a given ``classname``. If ``property_name``
	   is specified, that is the property that will be displayed for each
	   element. If ``property_name`` is not specified the default label
	   property will be used.

   display arguments: *designator, [property_1, ..., property_N]*

	   Display a single item in the tracker as specified by ``designator``
	   (e.g. issue20 or user5). The default is to display all properties
	   for the item. Alternatively, a list of properties to display can
	   be specified.

   create  arguments: *classname, arg_1 ... arg_N*

	   Create a new instance of ``classname`` with ``arg_1`` through
	   ``arg_N`` as the values of the new instance. The arguments are
	   name=value pairs (e.g. ``status='3'``).

   set     arguments: *designator, arg_1 ... arg_N*

	   Set the values of an existing item in the tracker as specified by
	   ``designator``. The new values are specified in ``arg_1`` through
	   ``arg_N``. The arguments are name=value pairs (e.g. ``status='3'``).

   lookup  arguments: *classname, key_value*

	   looks up the key_value for the given class. The class needs to
	   have a key and the user needs search permission on the key
	   attribute and id for the given classname.

   filter  arguments: *classname, list or None, attributes*

	   ``list`` is a list of ids to filter. It can be set to None to
	   run filter over all values (requires ``allow_none=True`` when
	   instantiating the ServerProxy). The ``attributes`` are given 
	   as a dictionary of name value pairs to search for. See also
	   :ref:`query-tracker`.
   ======= ===================================================================

Sample Python Client
====================

This client will work if you turn off the x-requested-with header and
the only CSRF header check you require is the HTTP host header::

        >>> import xmlrpclib
        >>> roundup_server = xmlrpclib.ServerProxy('http://admin:admin@localhost:8917/demo/xmlrpc', allow_none=True)
        >>> roundup_server.schema()
        {'user': [['username', '<roundup.hyperdb.String>'], ...], 'issue': [...]}
        >>> roundup_server.list('user')
        ['admin', 'anonymous', 'demo']
        >>> roundup_server.list('issue', 'id')
        ['1']
        >>> roundup_server.display('issue1')
        {'assignedto' : None, 'files' : [], 'title' = 'yes, ..... }
        >>> roundup_server.display('issue1', 'priority', 'status')
        {'priority' : '1', 'status' : '2'}
        >>> roundup_server.set('issue1', 'status=3')
        >>> roundup_server.display('issue1', 'status')
        {'status' : '3' }
        >>> roundup_server.create('issue', "title='another bug'", "status=2")
        '2'
        >>> roundup_server.filter('user',None,{'username':'adm'})
        ['1']
        >>> roundup_server.filter('user',['1','2'],{'username':'adm'})
        ['1']
        >>> roundup_server.filter('user',['2'],{'username':'adm'})
        []
        >>> roundup_server.filter('user',[],{'username':'adm'})
        []
        >>> roundup_server.lookup('user','admin')
        '1'

Advanced Python Client Adding anti-csrf Headers
===============================================

The one below adds Referer and X-Requested-With headers so it can pass
stronger CSRF detection methods. It also generates a fault message
from the server and reports it. Note if you are using http rather than
https, replace xmlrpclib.SafeTransport with xmlrpclib.Transport::

    try:
        from xmlrpc import client as xmlrpclib  # python 3
    except ImportError:
        import xmlrpclib  # python 2

    hostname="localhost"
    path="/demo"
    user_pw="admin:admin"

    class SpecialTransport(xmlrpclib.SafeTransport):

        def send_content(self, connection, request_body):

            connection.putheader("Referer", "https://%s%s/"%(hostname, path))
            connection.putheader("Origin", "https://%s"%hostname)
            connection.putheader("X-Requested-With", "XMLHttpRequest")

            connection.putheader("Content-Type", "text/xml")    
            connection.putheader("Content-Length", str(len(request_body)))
            connection.endheaders()
            if request_body:
                connection.send(request_body)

    roundup_server = xmlrpclib.ServerProxy(
        'https://%s@%s%s/xmlrpc'%(user_pw,hostname,path),
        transport=SpecialTransport(),
        verbose=False,
        allow_none=True)

    print(roundup_server.schema())
    print(roundup_server.display('user2', 'username'))
    print(roundup_server.display('issue1', 'status'))
    print(roundup_server.filter('user',['1','2','3'],{'username':'demo'}))

    # this will fail with a fault
    try:
        print(roundup_server.filter('usr',['0','2','3'],{'username':'demo'}))
    except Exception as msg:
        print(msg)

modify this script replacing the hostname, path and user_pw with those
for your tracker.

Roundup Issue Tracker: http://roundup-tracker.org/