Azure Storage¶
A custom storage system for Django using Windows Azure Storage backend.
Notes¶
Be aware Azure file names have some extra restrictions. They can’t:
- end with a dot (
.
) or slash (/
)- contain more than 256 slashes (
/
)- be longer than 1024 characters
This is usually not an issue, since some file-systems won’t
allow this anyway.
There’s default_storage.get_name_max_len()
method
to get the max_length
allowed. This is useful
for form inputs. It usually returns
1024 - len(azure_location_setting)
.
There’s default_storage.get_valid_name(...)
method
to clean up file names when migrating to Azure.
Gzipping for static files must be done through Azure CDN.
Private VS Public Access¶
The AzureStorage
allows a single container. The container may have either
public access or private access. When dealing with a private container, the
AZURE_URL_EXPIRATION_SECS
must be set to get temporary URLs.
A common setup is having private media files and public static files, since public files allow for better caching (i.e: no query-string within the URL).
One way to support this is having two backends, a regular AzureStorage
with the private container and expiration setting set, and a custom
backend (i.e: a subclass of AzureStorage
) for the public container.
Custom backend:
# file: ./custom_storage/custom_azure.py
class PublicAzureStorage(AzureStorage):
account_name = 'myaccount'
account_key = 'mykey'
azure_container = 'mypublic_container'
expiration_secs = None
Then on settings set:
DEFAULT_FILE_STORAGE = 'storages.backends.azure_storage.AzureStorage'
STATICFILES_STORAGE = 'custom_storage.custom_azure.PublicAzureStorage'
Settings¶
The following settings should be set within the standard django configuration file, usually settings.py.
Set the default storage (i.e: for media files) and the static storage (i.e: fo static files) to use the azure backend:
DEFAULT_FILE_STORAGE = 'storages.backends.azure_storage.AzureStorage'
STATICFILES_STORAGE = 'storages.backends.azure_storage.AzureStorage'
The following settings are available:
AZURE_ACCOUNT_NAME
This setting is the Windows Azure Storage Account name, which in many cases is also the first part of the url for instance: http://azure_account_name.blob.core.windows.net/ would mean:
AZURE_ACCOUNT_NAME = "azure_account_name"
AZURE_ACCOUNT_KEY
This is the private key that gives Django access to the Windows Azure Account.
AZURE_CONTAINER
This is where the files uploaded through Django will be uploaded. The container must be already created, since the storage system will not attempt to create it.
AZURE_SSL
Set a secure connection (HTTPS), otherwise it makes an insecure connection (HTTP). Default isTrue
AZURE_UPLOAD_MAX_CONN
Number of connections to make when uploading a single file. Default is2
AZURE_CONNECTION_TIMEOUT_SECS
Global connection timeout in seconds. Default is20
AZURE_BLOB_MAX_MEMORY_SIZE
Maximum memory used by a downloaded file before dumping it to disk. Unit is in bytes. Default is2MB
AZURE_URL_EXPIRATION_SECS
Seconds before a URL expires, set toNone
to never expire it. Be aware the container must have public read permissions in order to access a URL without expiration date. Default isNone
AZURE_OVERWRITE_FILES
Overwrite an existing file when it has the same name as the file being uploaded. Otherwise, rename it. Default isFalse
AZURE_LOCATION
Default location for the uploaded files. This is a path that gets prepended to every file name.
AZURE_CUSTOM_DOMAIN
The custom domain to use. This can be set in the Azure Portal. For example,www.mydomain.com
ormycdn.azureedge.net
.
AZURE_CONNECTION_STRING
If specified, this will override all other parameters. See http://azure.microsoft.com/en-us/documentation/articles/storage-configure-connection-string/ for the connection string format.
AZURE_TOKEN_CREDENTIAL
A token credential used to authenticate HTTPS requests. The token value should be updated before its expiration.
AZURE_CACHE_CONTROL
A variable to set the Cache-Control HTTP response header. E.g.AZURE_CACHE_CONTROL = "public,max-age=31536000,immutable"
AZURE_OBJECT_PARAMETERS
Use this to set content settings on all objects. To set these on a per-object basis, subclass the backend and override
AzureStorage.get_object_parameters
.This is a Python
dict
and the possible parameters are:content_type
,content_encoding
,content_language
,content_disposition
,cache_control
, andcontent_md5
.