Added a static/README file to provide guidance on the new static files setup.

 - Legacy-Id: 9887

Author: levkowetz

static/README.rst

@@ -0,0 +1,57 @@
+Handling of External Javascript and CSS Components 
+==================================================
+
+This directory (``static/``) holds a number of subdirectories, where one is handled
+differently than the rest: the ``lib/`` subdirectory holds distribution files for external
+client-side components, currently (18 Apr 2015) this means ``js`` and ``css`` components.
+
+These components each reside in their own subdirectory, which is named with the component
+name:
+
+    henrik@zinfandel $ ls -l static/lib
+    total 44
+    drwxr-xr-x 6 henrik henrik 4096 Jul 25 15:25 bootstrap
+    drwxr-xr-x 4 henrik henrik 4096 Jul 25 15:25 bootstrap-datepicker
+    drwxr-xr-x 4 henrik henrik 4096 Jul 25 15:25 font-awesome
+    drwxr-xr-x 2 henrik henrik 4096 Jul 25 15:25 jquery
+    drwxr-xr-x 2 henrik henrik 4096 Jul 25 15:25 jquery.cookie
+    drwxr-xr-x 2 henrik henrik 4096 Jul 25 15:24 ptmono
+    drwxr-xr-x 2 henrik henrik 4096 Jul 25 15:24 ptsans
+    drwxr-xr-x 2 henrik henrik 4096 Jul 25 15:24 ptserif
+    drwxr-xr-x 2 henrik henrik 4096 Jul 25 15:25 select2
+    drwxr-xr-x 2 henrik henrik 4096 Jul 25 15:25 select2-bootstrap-css
+
+If resources served over a CDN and/or with a high max-age don't have different URLs for
+different versions, then any component upgrade which is accompanied by a change in template
+functionality will be have a long transition time during which the new pages are served with
+old components, with possible breakage.  We want to avoid this.
+
+The intention is that after a release has been checked out, but before it is deployed,
+the whole static directory should be copied to a location which is accessible under the
+URL given by STATIC_URL -- in production mode this URL contains the datatracker release
+version, which will let the CDN serve the static files which correspond to the current
+release.
+
+With the exception of the ``pt*`` fonts, all components under ``static/lib/`` are managed
+through a bower_ file; ``ietf/static/bower.json``.  In order to install a new
+version of a component, you should update the ``bower.json`` file, and then run the management
+command::
+
+    $ ietf/manage.py bower_install
+
+That command will fetch the required version of each external component listed in
+``bower.json`` (actually, it will do this for *all* ``bower.json`` files found in the
+``static/`` directories of all ``INSTALLED_APPS``), saving them temporarily under
+``.tmp/bower_components/``; it will then extract the relevant ``js`` and ``css`` files and
+place them in an appropriately named directory under ``static/lib/``.  The location
+used by ``bower_install`` is is controlled by ``COMPONENT_ROOT`` in ``settings.py``.
+
+Any datatracker-specific static files which should be served by the CDN rather than
+directly by the datatracker web server should be moved from under ``static/ to ``ietf/static/``,
+so that they will be collected by the ``ietf/manage.py collectstatic`` command and
+placed under `static/lib/`` from where they will be made available to the CDN.  Any
+template files referencing the files in question will need to be updated to use the
+``{% static 'foo/bar.jpg' %}`` notation to reference the files, so that the correct
+static url will be emitted.
+
+.. _bower: http://bower.io/