--- /dev/null
+.. _design-decisions-chapter:
+
+==================
+ Design Decisions
+==================
+
+This chapter talks a bit about design decisions.
+
+
+Why Python
+==========
+
+Chris Webber on "Why Python":
+
+ Because I know Python, love Python, am capable of actually making
+ this thing happen in Python (I've worked on a lot of large free
+ software web applications before in Python, including `Miro
+ Community`_, the `Miro Guide`_, a large portion of `Creative
+ Commons`_, and a whole bunch of things while working at `Imaginary
+ Landscape`_). I know Python, I can make this happen in Python, me
+ starting a project like this makes sense if it's done in Python.
+
+ You might say that PHP is way more deployable, that Rails has way
+ more cool developers riding around on fixie bikes, and all of
+ those things are true. But I know Python, like Python, and think
+ that Python is pretty great. I do think that deployment in Python
+ is not as good as with PHP, but I think the days of shared hosting
+ are (thankfully) coming to an end, and will probably be replaced
+ by cheap virtual machines spun up on the fly for people who want
+ that sort of stuff, and Python will be a huge part of that future,
+ maybe even more than PHP will. The deployment tools are getting
+ better. Maybe we can use something like Silver Lining. Maybe we
+ can just distribute as ``.debs`` or ``.rpms``. We'll figure it
+ out when we get there.
+
+ Regardless, if I'm starting this project, which I am, it's gonna
+ be in Python.
+
+.. _Miro Community: http://mirocommunity.org/
+.. _Miro Guide: http://miroguide.org/
+.. _Creative Commons: http://creativecommons.org/
+.. _Imaginary Landscape: http://www.imagescape.com/
+
+
+Why WSGI Minimalism
+===================
+
+Chris Webber on "Why WSGI Minimalism":
+
+ If you notice in the technology list above, I list a lot of
+ components that are very `Django Project`_, but not actually
+ Django components. What can I say, I really like a lot of the
+ ideas in Django! Which leads to the question: why not just use
+ Django?
+
+ While I really like Django's ideas and a lot of its components, I
+ also feel that most of the best ideas in Django I want have been
+ implemented as good or even better outside of Django. I could
+ just use Django and replace the templating system with Jinja2, and
+ the form system with wtforms, and the database with MongoDB and
+ MongoKit, but at that point, how much of Django is really left?
+
+ I also am sometimes saddened and irritated by how coupled all of
+ Django's components are. Loosely coupled yes, but still coupled.
+ WSGI has done a good job of providing a base layer for running
+ applications on and if you know how to do it yourself [1]_, it's
+ not hard or many lines of code at all to bind them together
+ without any framework at all (not even say `Pylons`_, `Pyramid`_
+ or `Flask`_ which I think are still great projects, especially for
+ people who want this sort of thing but have no idea how to get
+ started). And even at this already really early stage of writing
+ MediaGoblin, that glue work is mostly done.
+
+ Not to say I don't think Django isn't great for a lot of things.
+ For a lot of stuff, it's still the best, but not for MediaGoblin,
+ I think.
+
+ One thing that Django does super well though is documentation. It
+ still has some faults, but even with those considered I can hardly
+ think of any other project in Python that has as nice of
+ documentation as Django. It may be worth learning some lessons on
+ documentation from Django [2]_, on that note.
+
+ I'd really like to have a good, thorough hacking-howto and
+ deployment-howto, especially in the former making some notes on
+ how to make it easier for Django hackers to get started.
+
+.. _Django Project: http://www.djangoproject.com/
+.. _Pylons: http://pylonshq.com/
+.. _Pyramid: http://docs.pylonsproject.org/projects/pyramid/dev/
+.. _Flask: http://flask.pocoo.org/
+
+.. [1] http://pythonpaste.org/webob/do-it-yourself.html
+.. [2] http://pycon.blip.tv/file/4881071/
+
+
+Why MongoDB
+===========
+
+Chris Webber on "Why MongoDB":
+
+ In case you were wondering, I am not a NOSQL fanboy, I do not go
+ around telling people that MongoDB is web scale. Actually my
+ choice for MongoDB isn't scalability, though scaling up really
+ nicely is a pretty good feature and sets us up well in case large
+ volume sites eventually do use MediaGoblin. But there's another
+ side of scalability, and that's scaling down, which is important
+ for federation, maybe even more important than scaling up in an
+ ideal universe where everyone ran servers out of their own
+ housing. As a memory-mapped database, MongoDB is pretty hungry,
+ so actually I spent a lot of time debating whether the inability
+ to scale down as nicely as something like SQL has with sqlite
+ meant that it was out.
+
+ But I decided in the end that I really want MongoDB, not for
+ scalability, but for flexibility. Schema evolution pains in SQL
+ are almost enough reason for me to want MongoDB, but not quite.
+ The real reason is because I want the ability to eventually handle
+ multiple media types through MediaGoblin, and also allow for
+ plugins, without the rigidity of tables making that difficult. In
+ other words, something like::
+
+ {"title": "Me talking until you are bored",
+ "description": "blah blah blah",
+ "media_type": "audio",
+ "media_data": {
+ "length": "2:30",
+ "codec": "OGG Vorbis"},
+ "plugin_data": {
+ "licensing": {
+ "license": "http://creativecommons.org/licenses/by-sa/3.0/"}}}
+
+
+ Being able to just dump media-specific information in a media_data
+ hashtable is pretty great, and even better is having a plugin
+ system where you can just let plugins have their own entire
+ key-value space cleanly inside the document that doesn't interfere
+ with anyone else's stuff. If we were to let plugins to deposit
+ their own information inside the database, either we'd let plugins
+ create their own tables which makes SQL migrations even harder
+ than they already are, or we'd probably end up creating a table
+ with a column for key, a column for value, and a column for type
+ in one huge table called "plugin_data" or something similar. (Yo
+ dawg, I heard you liked plugins, so I put a database in your
+ database so you can query while you query.) Gross.
+
+ I also don't want things to be too lose so that we forget or lose
+ the structure of things, and that's one reason why I want to use
+ MongoKit, because we can cleanly define a much structure as we
+ want and verify that documents match that structure generally
+ without adding too much bloat or overhead (mongokit is a pretty
+ lightweight wrapper and doesn't inject extra mongokit-specific
+ stuff into the database, which is nice and nicer than many other
+ ORMs in that way).
+
+
+Why Sphinx for documentation
+============================
+
+Will Kahn-Greene on "Why Sphinx":
+
+ Sphinx is a fantastic tool for organizing documentation for a
+ Python-based project that makes it pretty easy to write docs that
+ are readable in source form and can be "compiled" into HTML, LaTeX
+ and other formats.
+
+ There are other doc systems out there, but given that GNU
+ MediaGoblin is being written in Python, it makes sense to use
+ Sphinx for now.
+
--- /dev/null
+=======
+ Stack
+=======
+
+The software stack for this project might change over time, but this
+is what we're thinking right now.
+
+There's some explanation of design decisions in the
+:ref:`design-decisions-chapter`.
+
+
+Python
+======
+
+* http://python.org/
+
+The core team does a lot of work in Python and it's the language we're
+most likely to do a project like this in.
+
+
+MongoDB
+=======
+
+* http://www.mongodb.org/
+
+A "document database". Because it's extremely flexible and scales up
+well, but I guess not down well.
+
+
+MongoKit
+========
+
+* http://namlook.github.com/mongokit/
+
+A lightweight ORM for mongodb. Helps us define our structures better,
+does schema validation, schema evolution, and helps make things more
+fun and pythonic.
+
+
+Jinja2
+======
+
+* http://jinja.pocoo.org/docs/
+
+For templating. Pretty much django templates++ but allows us to pass
+arguments into method calls instead of writing custom tags.
+
+
+WTForms
+=======
+
+* http://wtforms.simplecodes.com/
+
+For form handling, validation, abstraction. Almost just like Django's
+templates.
+
+
+WebOb
+=====
+
+* http://pythonpaste.org/webob/
+
+Gives nice request/response objects (also somewhat Django-ish).
+
+
+Paste Deploy and Paste Script
+=============================
+
+* http://pythonpaste.org/deploy/
+* http://pythonpaste.org/script/
+
+This will be the default way of configuring and launching the
+application. Since GNU MediaGoblin will be fairly WSGI minimalist though,
+you can probably use other ways to launch it, though this will be the
+default.
+
+
+Routes
+======
+
+* http://routes.groovie.org/
+
+For URL Routing. It works well enough.
+
+
+JQuery
+======
+
+* http://jquery.com/
+
+For all sorts of things on the JavaScript end of things, for all sorts
+of reasons.
+
+
+Beaker
+======
+
+* http://beaker.groovie.org/
+
+For sessions, because that seems like it's generally considered the
+way to go I guess.
+
+
+Nose
+====
+
+* http://somethingaboutorange.com/mrl/projects/nose/1.0.0/
+
+For unit tests because it makes testing a bit nicer.
+
+
+Celery
+======
+
+* http://celeryproject.org/
+
+For task queueing (resizing images, encoding video, ...).
+
+
+RabbitMQ
+========
+
+* http://www.rabbitmq.com/
+
+For sending tasks to celery, because I guess that's what most people
+do. Might be optional, might also let people use MongoDB for this if
+they want.
projects / mediagoblin.git / commitdiff