Django-compressor: how to write to S3, read from CloudFront?

Question

I want to serve my compressed CSS/JS from CloudFront (they live on S3), but am unable to work out how to do it via the compressor settings in settings.py, I have the followi

Answer 1

I made a few, different changes to settings.py

AWS_S3_CUSTOM_DOMAIN = 'XXXXXXX.cloudfront.net' #important: no "http://"
AWS_S3_SECURE_URLS = True #default, but must set to false if using an alias on cloudfront

COMPRESS_STORAGE = 'example_app.storage.CachedS3BotoStorage' #from the docs (linked below)
STATICFILES_STORAGE = 'example_app.storage.CachedS3BotoStorage'

Compressor Docs

This above solution saved the files locally as well as uploaded them to s3. This let me compress the files offline. If you aren't gzipping, the above ought to work for serving compressed files from CloudFront.

Adding gzip adds a wrinkle:

settings.py

AWS_IS_GZIPPED = True

though this resulted in an error whenever a compressible file (css and js according to storages) was being pushed to s3 during collectstatic:

AttributeError: 'cStringIO.StringO' object has no attribute 'name'

This was due to some bizarre error having to do with the compression of the css/js files that I don't understand. These files I need locally, unzipped, and not on s3, so I could do avoid the problem altogether if I tweak the storage subclass referenced above (and provided in the compressor docs).

new storage.py

from os.path import splitext 
from django.core.files.storage import get_storage_class  
from storages.backends.s3boto import S3BotoStorage  


class StaticToS3Storage(S3BotoStorage): 

    def __init__(self, *args, **kwargs): 
        super(StaticToS3Storage, self).__init__(*args, **kwargs) 
        self.local_storage = get_storage_class('compressor.storage.CompressorFileStorage')() 

    def save(self, name, content): 
        ext = splitext(name)[1] 
        parent_dir = name.split('/')[0] 
        if ext in ['.css', '.js'] and not parent_dir == 'admin': 
            self.local_storage._save(name, content) 
        else:     
            filename = super(StaticToS3Storage, self).save(name, content) 
            return filename 

This then saved all .css and .js files (excluding the admin files, which I serve uncompressed from CloudFront) while pushing the rest of the files to s3 (and not bothering to save them locally, though could easily add the self.local_storage._save line).

But when I run compress, I want my compressed .js and .css files to get pushed to s3 so I create another sublcass for compressor to use:

class CachedS3BotoStorage(S3BotoStorage): 
        """ 
        django-compressor uses this class to gzip the compressed files and send them to s3 
        these files are then saved locally, which ensures that they only create fresh copies 
        when they need to 
        """ 
        def __init__(self, *args, **kwargs): 
            super(CachedS3BotoStorage, self).__init__(*args, **kwargs) 
            self.local_storage = get_storage_class('compressor.storage.CompressorFileStorage')() 


        def save(self, filename, content): 
            filename = super(CachedS3BotoStorage, self).save(filename, content) 
            self.local_storage._save(filename, content) 
            return filename 

Finally, given these new subclasses, I need to update a few settings:

COMPRESS_STORAGE = 'example_app.storage.CachedS3BotoStorage' #from the docs (linked below)
STATICFILES_STORAGE = 'example_app.storage.StaticToS3Storage'

And that is all I have to say about that.