A Django module which extends pyfilesystem with several methods to make it convenient for web use. Specifically, it extends pyfilesystem with two methods:
fs.get_url(filename, timeout=0)
This will return a externally-usable URL to the resource. If timeout>0, the URL may stop working after that period (in seconds). Details are implementation-dependent. On Amazon S3, this is a secure URL, which is only available for that period. For a static filesystem, the URLs are unsecure and permanent.
fs.expire(filename, seconds, days, expires=True)
This allows us to create temporary objects. Our use-case was that we wanted to generate visualizations to users which were .png images. The lifetime of those images was a single web request, so we set them to expire after a few minutes. Another use case was memoization.
Note that expired files are not automatically removed. To remove them,
call expire_objects(). In our system, we had a cron job do
this for a while. Celery, manual removals, etc. are all options.
To configure a django-pyfs to use static files, set a parameter in Django settings:
DJFS = {'type' : 'osfs',
'directory_root' : 'djpyfs/static/djpyfs',
'url_root' : '/static/djpyfs'}
Here, directory_root is where the files go. url_root is the URL
base of where your web server is configured to serve them from.
To use files on S3, you need boto installed. Then,
DJFS = {'type' : 's3fs',
'bucket' : 'my-bucket',
'prefix' : '/pyfs/' }
bucket is your S3 bucket. prefix is optional, and gives a base
within that bucket.
To get your filesystem, call:
def get_filesystem(namespace)
Each module should pass a unique namespace. These will typically correspond to subdirectories within the filesystem.
The django-pyfs interface is designed as a generic (non-Django specific) extension to pyfilesystem. However, the specific implementation is very Django-specific.
Good next steps would be to:
- Allow Django storages to act as a back-end for pyfilesystem
- Allow django-pyfs to act as a back-end for Django storages
- Support more types of pyfilesystems (esp. in-memory would be nice)
- General code cleanup, documentation, test cases, etc.
- Add better test support. Django does nice things with resetting DBs to a know state for testing. It'd be nice to do the same here.
State: This code is tested and has worked well in a range of settings, and is currently deployed on edx.org. However, it doesn't have test cases and similar, so can't be considered truly production-ready. The expiration functionality, in particular, we are not using right now.