Environmental Variables
=======================

This document describes all the environmental variables that Silver
Lining creates, that an application might want to use (or just might
notice).

``SILVER_VERSION``:

    This gives the version in the form ``context/version``, like
    ``silverlining/0.0`` or ``devel/0.0``.  Having not had a release,
    there is no real version information yet, but this can be used to
    detect the difference between production and development
    environments.  (Also ``silversupport.env.is_production()`` does
    this.)

``SILVER_INSTANCE_NAME``:

    This is the name of the instance/deployment.

``SILVER_MATCH_PATH``:

    This is the portion of the path that was matched during dispatch.
    For instance if you upload an app to ``site.example.com/blog``
    then ``SILVER_MATCH_PATH`` will be ``/blog``.

``SILVER_APP_NAME``:

    This is the name of the application.  If ``SILVER_INSTANCE_NAME`` is
    ``blog.20100319_004`` then this will probably be ``blog``.

``SILVER_APP_CONFIG``:

    This is a directory that contains the application's configuration
    (as uploaded using ``silver update --config DIR``).

``SILVER_CANONICAL_HOSTNAME``:

    This is what *might* be considered the "canonical" (i.e., main)
    hostname of the application.  This is calculated as the *shortest*
    hostname possible.  When only one hostname is mapped to an
    application this is always correct.

``SILVER_LOGS``:

    This is a directory where log files should be kept.  This is a
    per-application directory.  In development it will be in
    ``silver-logs/`` under your application's main directory (what you
    created with ``silver init``).

``CONFIG_*``:

    This is the naming convention for all the information coming from
    services.

``TEMP``:

    This points to a place to put "temporary" files.  These are files
    that don't have to exist forever (the ``service.files`` service
    and ``CONFIG_FILES`` should be used for such files), but is a good
    place to put cache files.  You can also keep files in ``/tmp`` but
    using ``TEMP`` is more cleanly.  Some modules like `tempfile
    <http://docs.python.org/library/tempfile.html>`_ will
    automatically look at this variable.

    This directory is cleared everytime the application is uploaded.