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.. IVLE - Informatics Virtual Learning Environment
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Copyright (C) 2007-2009 The University of Melbourne
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.. This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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.. This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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.. You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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This page describes the various subsystems of IVLE.
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.. image:: /images/ivle-system-diagram.png
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The IVLE web application
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========================
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User management server
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======================
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The "user management" server (:file:`usrmgt-server`) is an
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inappropriately-named program which must be run as root in the background of
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an IVLE instance. It is responsible for performing tasks at the request of the
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IVLE web application, which require root privileges:
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* Activating users when they first log into the system (including the creation
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of jails and user Subversion repositories).
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* Creating group Subversion repositories.
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* Rebuilding Subversion configuration files.
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There are two mechanisms by which IVLE can connect to an external server to
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get information about users. These are typically used to connect to an
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institution's central database to authenticate students, and download student
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details (such as names and subject enrolment details).
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Neither of these mechanisms are necessary; they are only useful where
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third-party authentication is required.
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IVLE's database contains user accounts, which includes a password (hash)
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field. In this way, IVLE is fully-functioning without third-party
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authentication modules. However, it is also often desirable to allow users to
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log in without storing their password hash in the local database. IVLE allows
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plug-in "auth modules" which can authenticate users with arbitrary logic, and
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also create new user accounts.
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This has at least the following two use cases:
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* Allowing users to authenticate upon each login with a remote server. This
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allows users to log in without ever storing their password hash locally.
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* Allowing users who have never used IVLE to log in, without an IVLE user
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account. Upon seeing an unknown username, an auth module can connect to a
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remote server, authenticate the unknown user, and create an IVLE user
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account on-the-fly, optionally downloading additional details (such as full
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TODO: Describe how auth modules work.
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.. _ref-subject-pulldown-modules:
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Subject pulldown modules
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------------------------
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IVLE maintains lists of enrolled students in each subject, providing access to
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worksheets and allowing submissions for enrolled users. Again, enrolments can
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be made manually, but IVLE also allows plug-in "subject pulldown modules"
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which can enrol students with arbitrary logic.
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This allows a third-party server to dictate which IVLE users are enrolled in
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Subject pulldown modules are used by the :program:`ivle-enrolallusers` script
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to automatically enrol all existing users in subjects. Note that this does not
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enrol users who are not in the IVLE database (perhaps because a third-party
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auth module is being used to create user accounts on-the-fly, and some
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students have not yet logged in for the first time).
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Because of this, subject pulldown modules are also used whenever a student
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logs in. This ensures that students who log in for the first time are
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automatically enrolled in all subjects, according to the third-party server,
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and also ensures that enrolments are kept up-to-date, should the third-party
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server add new enrolments, or should new subjects be created in IVLE.
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Enrolments are never removed by subject pulldown modules, only added.
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Students can only be un-enrolled from a subject by an administrator.
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TODO: Describe how subject pulldown modules work.
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doc/man/architecture.rst
