Amazon S3

Usage

There are two backends for interacting with Amazon’s S3, one based on boto3 and an older one based on boto. It is highly recommended that all new projects (at least) use the boto3 backend since it has many bug fixes and performance improvements over boto and is the future; boto is lightly maintained if at all. The boto based backed will continue to be maintained for the forseeable future.

For historical completeness an extreme legacy backend was removed in version 1.2

Settings

To use boto3 set:

DEFAULT_FILE_STORAGE = 'storages.backends.s3boto3.S3Boto3Storage'

To use the boto version of the backend set:

DEFAULT_FILE_STORAGE = 'storages.backends.s3boto.S3BotoStorage'

To allow django-admin.py collectstatic to automatically put your static files in your bucket set the following in your settings.py:

STATICFILES_STORAGE = 'storages.backends.s3boto3.S3Boto3Storage'

Available are numerous settings. It should be especially noted the following:

AWS_ACCESS_KEY_ID
Your Amazon Web Services access key, as a string.
AWS_SECRET_ACCESS_KEY
Your Amazon Web Services secret access key, as a string.
AWS_STORAGE_BUCKET_NAME
Your Amazon Web Services storage bucket name, as a string.
AWS_DEFAULT_ACL (optional)
If set to private changes uploaded file’s Access Control List from the default permission public-read to give owner full control and remove read access from everyone else.
AWS_AUTO_CREATE_BUCKET (optional)
If set to True the bucket specified in AWS_STORAGE_BUCKET_NAME is automatically created.
AWS_HEADERS (optional)

If you’d like to set headers sent with each file of the storage:

# see http://developer.yahoo.com/performance/rules.html#expires
AWS_HEADERS = {
    'Expires': 'Thu, 15 Apr 2010 20:00:00 GMT',
    'Cache-Control': 'max-age=86400',
}
AWS_QUERYSTRING_AUTH (optional; default is True)
Setting AWS_QUERYSTRING_AUTH to False removes query parameter authentication from generated URLs. This can be useful if your S3 buckets are public.
AWS_QUERYSTRING_EXPIRE (optional; default is 3600 seconds)
The number of seconds that a generated URL with query parameter authentication is valid for.
AWS_S3_ENCRYPTION (optional; default is False)
Enable server-side file encryption while at rest, by setting encrypt_key parameter to True. More info available here: http://boto.cloudhackers.com/en/latest/ref/s3.html
AWS_S3_FILE_OVERWRITE (optional: default is True)
By default files with the same name will overwrite each other. Set this to False to have extra characters appended.
AWS_LOCATION (optional: default is ‘’)
A path prefix that will be prepended to all uploads

CloudFront

If you’re using S3 as a CDN (via CloudFront), you’ll probably want this storage to serve those files using that:

AWS_S3_CUSTOM_DOMAIN = 'cdn.mydomain.com'

Keep in mind you’ll have to configure CloudFront to use the proper bucket as an origin manually for this to work.

If you need to use multiple storages that are served via CloudFront, pass the custom_domain parameter to their constructors.

Storage

Standard file access options are available, and work as expected:

>>> default_storage.exists('storage_test')
False
>>> file = default_storage.open('storage_test', 'w')
>>> file.write('storage contents')
>>> file.close()

>>> default_storage.exists('storage_test')
True
>>> file = default_storage.open('storage_test', 'r')
>>> file.read()
'storage contents'
>>> file.close()

>>> default_storage.delete('storage_test')
>>> default_storage.exists('storage_test')
False

Model

An object without a file has limited functionality:

>>> obj1 = MyStorage()
>>> obj1.normal
<FieldFile: None>
>>> obj1.normal.size
Traceback (most recent call last):
...
ValueError: The 'normal' attribute has no file associated with it.

Saving a file enables full functionality:

>>> obj1.normal.save('django_test.txt', ContentFile('content'))
>>> obj1.normal
<FieldFile: tests/django_test.txt>
>>> obj1.normal.size
7
>>> obj1.normal.read()
'content'

Files can be read in a little at a time, if necessary:

>>> obj1.normal.open()
>>> obj1.normal.read(3)
'con'
>>> obj1.normal.read()
'tent'
>>> '-'.join(obj1.normal.chunks(chunk_size=2))
'co-nt-en-t'

Save another file with the same name:

>>> obj2 = MyStorage()
>>> obj2.normal.save('django_test.txt', ContentFile('more content'))
>>> obj2.normal
<FieldFile: tests/django_test_.txt>
>>> obj2.normal.size
12

Push the objects into the cache to make sure they pickle properly:

>>> cache.set('obj1', obj1)
>>> cache.set('obj2', obj2)
>>> cache.get('obj2').normal
<FieldFile: tests/django_test_.txt>

Deleting an object deletes the file it uses, if there are no other objects still using that file:

>>> obj2.delete()
>>> obj2.normal.save('django_test.txt', ContentFile('more content'))
>>> obj2.normal
<FieldFile: tests/django_test_.txt>

Default values allow an object to access a single file:

>>> obj3 = MyStorage.objects.create()
>>> obj3.default
<FieldFile: tests/default.txt>
>>> obj3.default.read()
'default content'

But it shouldn’t be deleted, even if there are no more objects using it:

>>> obj3.delete()
>>> obj3 = MyStorage()
>>> obj3.default.read()
'default content'

Verify the fix for #5655, making sure the directory is only determined once:

>>> obj4 = MyStorage()
>>> obj4.random.save('random_file', ContentFile('random content'))
>>> obj4.random
<FieldFile: .../random_file>

Clean up the temporary files:

>>> obj1.normal.delete()
>>> obj2.normal.delete()
>>> obj3.default.delete()
>>> obj4.random.delete()