Django-compressor Error on Heroku & Amazon S3 "UncompressableFileError"

Question

So I know there are a few articles on this subject already, but I have tried every combination of settings to make django-compressor work, but with no success. Any ideas?

settings.py

STATICFILES_FINDERS = (
    'django.contrib.staticfiles.finders.FileSystemFinder',
    'django.contrib.staticfiles.finders.AppDirectoriesFinder',
    # other finders..
    'compressor.finders.CompressorFinder',
)
STATICFILES_DIRS = (
    os.path.join(BASE_DIR, "static"),
)
STATIC_ROOT = os.path.join(BASE_DIR, 'staticfiles/')
STATIC_URL = '/static/'

DEFAULT_FILE_STORAGE = "mysite.s3utils.MediaS3BotoStorage"

COMPRESS_ROOT = STATIC_ROOT
STATICFILES_STORAGE = 'mysite.storage.CachedS3BotoStorage'
COMPRESS_STORAGE = STATICFILES_STORAGE
COMPRESS_URL = STATIC_URL

s3utils.py

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


class StaticS3BotoStorage(S3BotoStorage):
    """
    Storage for static files.
    """

    def __init__(self, *args, **kwargs):
        kwargs['location'] = 'static'
        super().__init__(*args, **kwargs)


class MediaS3BotoStorage(S3BotoStorage):
    """
    Storage for uploaded media files.
    """

    def __init__(self, *args, **kwargs):
        kwargs['location'] = 'media'
        super().__init__(*args, **kwargs)


class CachedS3BotoStorage(S3BotoStorage):
    """
    S3 storage backend that saves the files locally, too.
    """
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.local_storage = get_storage_class(
            "compressor.storage.CompressorFileStorage")()

    def save(self, name, content):
        self.local_storage._save(name, content)
        super().save(name, self.local_storage._open(name))
        return name

index.html

{% load compress %}
{% compress css %}
<link href="{% static 'libs/twitter-bootstrap/css/bootstrap.min.css' %}" rel="stylesheet">
{% endcompress %}

Error:

compressor.exceptions.UncompressableFileError: 'https://mysite.s3.amazonaws.com:443/libs/twitter-bootstrap/css/bootstrap.min.css' isn't accessible via COMPRESS_URL ('https://mysite.s3.amazonaws.com/static/') and can't be compressed

So I know from the traceback error that this error is being raised because django-compressor uses the code:

if not url.startswith(base_url):
    raise UncompressableFileError(
        "'%s' isn't accesible via COMPRESS_URL ('%s') and can't be"
        " compressed" % (url, base_url))

so it seems that for some reason the COMPRESS_URL is using the :443 port, and is missing the /static/ suffix, otherwise it would be working.

Setup:

Django v1.10.6
Python v3.5
Django-compressor 2.1.1

Laurent S Laurent S · Accepted Answer · 2017-03-11T14:55:23

From the docs, it looks like you should set:

COMPRESS_URL = "http://mysite.s3.amazonaws.com/"

instead of a partial URL like your question shows. But I'm not even sure that it's your problem, given the setup you're using. (my understanding is that you want compressor to fetch files on S3 and store the compressed result locally)

Looking at django source code for Storage class, I'd check what you have for MEDIA_URL in your settings, that might be where the port 443 is from.

If that doesn't help, I'd suggest you post the full traceback of your error, it may help understand what is going on.

Django-compressor Error on Heroku & Amazon S3 "UncompressableFileError"

1 Answers