import mimetypes from datetime import datetime from datetime import timedelta from tempfile import SpooledTemporaryFile from azure.core.exceptions import ResourceNotFoundError from azure.storage.blob import BlobClient from azure.storage.blob import BlobSasPermissions from azure.storage.blob import BlobServiceClient from azure.storage.blob import ContentSettings from azure.storage.blob import generate_blob_sas from django.core.exceptions import SuspiciousOperation from django.core.files.base import File from django.utils import timezone from django.utils.deconstruct import deconstructible from storages.base import BaseStorage from storages.utils import clean_name from storages.utils import get_available_overwrite_name from storages.utils import safe_join from storages.utils import setting from storages.utils import to_bytes @deconstructible class AzureStorageFile(File): def __init__(self, name, mode, storage): self.name = name self._mode = mode self._storage = storage self._is_dirty = False self._file = None self._path = storage._get_valid_path(name) def _get_file(self): if self._file is not None: return self._file file = SpooledTemporaryFile( max_size=self._storage.max_memory_size, suffix=".AzureStorageFile", dir=setting("FILE_UPLOAD_TEMP_DIR", None)) if 'r' in self._mode or 'a' in self._mode: download_stream = self._storage.client.download_blob( self._path, timeout=self._storage.timeout) download_stream.readinto(file) if 'r' in self._mode: file.seek(0) self._file = file return self._file def _set_file(self, value): self._file = value file = property(_get_file, _set_file) def read(self, *args, **kwargs): if 'r' not in self._mode and 'a' not in self._mode: raise AttributeError("File was not opened in read mode.") return super().read(*args, **kwargs) def write(self, content): if ('w' not in self._mode and '+' not in self._mode and 'a' not in self._mode): raise AttributeError("File was not opened in write mode.") self._is_dirty = True return super().write(to_bytes(content)) def close(self): if self._file is None: return if self._is_dirty: self._file.seek(0) self._storage._save(self.name, self._file) self._is_dirty = False self._file.close() self._file = None def _content_type(content): try: return content.file.content_type except AttributeError: pass try: return content.content_type except AttributeError: pass return None def _get_valid_path(s): # A blob name: # * must not end with dot or slash # * can contain any character # * must escape URL reserved characters # (not needed here since the azure client will do that) s = s.strip('./') if len(s) > _AZURE_NAME_MAX_LEN: raise ValueError( "File name max len is %d" % _AZURE_NAME_MAX_LEN) if not len(s): raise ValueError( "File name must contain one or more " "printable characters") if s.count('/') > 256: raise ValueError( "File name must not contain " "more than 256 slashes") return s # Max len according to azure's docs _AZURE_NAME_MAX_LEN = 1024 @deconstructible class AzureStorage(BaseStorage): def __init__(self, **settings): super().__init__(**settings) self._service_client = None self._custom_service_client = None self._client = None self._custom_client = None self._user_delegation_key = None self._user_delegation_key_expiry = datetime.utcnow() def get_default_settings(self): return { "account_name": setting("AZURE_ACCOUNT_NAME"), "account_key": setting("AZURE_ACCOUNT_KEY"), "object_parameters": setting("AZURE_OBJECT_PARAMETERS", {}), "azure_container": setting("AZURE_CONTAINER"), "azure_ssl": setting("AZURE_SSL", True), "upload_max_conn": setting("AZURE_UPLOAD_MAX_CONN", 2), "timeout": setting('AZURE_CONNECTION_TIMEOUT_SECS', 20), "max_memory_size": setting('AZURE_BLOB_MAX_MEMORY_SIZE', 2*1024*1024), "expiration_secs": setting('AZURE_URL_EXPIRATION_SECS'), "overwrite_files": setting('AZURE_OVERWRITE_FILES', False), "location": setting('AZURE_LOCATION', ''), "default_content_type": 'application/octet-stream', "cache_control": setting("AZURE_CACHE_CONTROL"), "sas_token": setting('AZURE_SAS_TOKEN'), "endpoint_suffix": setting('AZURE_ENDPOINT_SUFFIX', 'core.windows.net'), "custom_domain": setting('AZURE_CUSTOM_DOMAIN'), "connection_string": setting('AZURE_CONNECTION_STRING'), "token_credential": setting('AZURE_TOKEN_CREDENTIAL'), "api_version": setting('AZURE_API_VERSION', None), } def _get_service_client(self, use_custom_domain): if self.connection_string is not None: return BlobServiceClient.from_connection_string(self.connection_string) account_domain = self.custom_domain if self.custom_domain and use_custom_domain else "{}.blob.{}".format( self.account_name, self.endpoint_suffix, ) account_url = "{}://{}".format(self.azure_protocol, account_domain) credential = None if self.account_key: credential = { "account_name": self.account_name, "account_key": self.account_key, } elif self.sas_token: credential = self.sas_token elif self.token_credential: credential = self.token_credential options = {} if self.api_version: options["api_version"] = self.api_version return BlobServiceClient(account_url, credential=credential, **options) @property def service_client(self): if self._service_client is None: self._service_client = self._get_service_client(use_custom_domain=False) return self._service_client @property def custom_service_client(self): if self._custom_service_client is None: self._custom_service_client = self._get_service_client(use_custom_domain=True) return self._custom_service_client @property def client(self): if self._client is None: self._client = self.service_client.get_container_client( self.azure_container ) return self._client @property def custom_client(self): if self._custom_client is None: self._custom_client = self.custom_service_client.get_container_client( self.azure_container ) return self._custom_client def get_user_delegation_key(self, expiry): # We'll only be able to get a user delegation key if we've authenticated with a # token credential. if self.token_credential is None: return None # Get a new key if we don't already have one, or if the one we have expires too # soon. if ( self._user_delegation_key is None or expiry > self._user_delegation_key_expiry ): now = datetime.utcnow() key_expiry_time = now + timedelta(days=7) self._user_delegation_key = self.custom_service_client.get_user_delegation_key( key_start_time=now, key_expiry_time=key_expiry_time ) self._user_delegation_key_expiry = key_expiry_time return self._user_delegation_key @property def azure_protocol(self): if self.azure_ssl: return 'https' else: return 'http' def _normalize_name(self, name): try: return safe_join(self.location, name) except ValueError: raise SuspiciousOperation("Attempted access to '%s' denied." % name) def _get_valid_path(self, name): # Must be idempotent return _get_valid_path( self._normalize_name( clean_name(name))) def _open(self, name, mode="rb"): return AzureStorageFile(name, mode, self) def get_available_name(self, name, max_length=_AZURE_NAME_MAX_LEN): """ Returns a filename that's free on the target storage system, and available for new content to be written to. """ name = clean_name(name) if self.overwrite_files: return get_available_overwrite_name(name, max_length) return super().get_available_name(name, max_length) def exists(self, name): blob_client = self.client.get_blob_client(self._get_valid_path(name)) return blob_client.exists() def delete(self, name): try: self.client.delete_blob( self._get_valid_path(name), timeout=self.timeout) except ResourceNotFoundError: pass def size(self, name): blob_client = self.client.get_blob_client(self._get_valid_path(name)) properties = blob_client.get_blob_properties(timeout=self.timeout) return properties.size def _save(self, name, content): cleaned_name = clean_name(name) name = self._get_valid_path(name) params = self._get_content_settings_parameters(name, content) # Unwrap django file (wrapped by parent's save call) if isinstance(content, File): content = content.file content.seek(0) self.client.upload_blob( name, content, content_settings=ContentSettings(**params), max_concurrency=self.upload_max_conn, timeout=self.timeout, overwrite=self.overwrite_files) return cleaned_name def _expire_at(self, expire): # azure expects time in UTC return datetime.utcnow() + timedelta(seconds=expire) def url(self, name, expire=None, parameters=None): name = self._get_valid_path(name) params = parameters or {} if expire is None: expire = self.expiration_secs credential = None if expire: expiry = self._expire_at(expire) user_delegation_key = self.get_user_delegation_key(expiry) sas_token = generate_blob_sas( self.account_name, self.azure_container, name, account_key=self.account_key, user_delegation_key=user_delegation_key, permission=BlobSasPermissions(read=True), expiry=expiry, **params ) credential = sas_token container_blob_url = self.custom_client.get_blob_client(name).url return BlobClient.from_blob_url(container_blob_url, credential=credential).url def _get_content_settings_parameters(self, name, content=None): params = {} guessed_type, content_encoding = mimetypes.guess_type(name) content_type = ( _content_type(content) or guessed_type or self.default_content_type) params['cache_control'] = self.cache_control params['content_type'] = content_type params['content_encoding'] = content_encoding params.update(self.get_object_parameters(name)) return params def get_object_parameters(self, name): """ Returns a dictionary that is passed to content settings. Override this method to adjust this on a per-object basis to set e.g ContentDisposition. By default, returns the value of AZURE_OBJECT_PARAMETERS. """ return self.object_parameters.copy() def get_modified_time(self, name): """ Returns an (aware) datetime object containing the last modified time if USE_TZ is True, otherwise returns a naive datetime in the local timezone. """ blob_client = self.client.get_blob_client(self._get_valid_path(name)) properties = blob_client.get_blob_properties(timeout=self.timeout) if not setting('USE_TZ', False): return timezone.make_naive(properties.last_modified) tz = timezone.get_current_timezone() if timezone.is_naive(properties.last_modified): return timezone.make_aware(properties.last_modified, tz) # `last_modified` is in UTC time_zone, we # must convert it to settings time_zone return properties.last_modified.astimezone(tz) def modified_time(self, name): """Returns a naive datetime object containing the last modified time.""" mtime = self.get_modified_time(name) if timezone.is_naive(mtime): return mtime return timezone.make_naive(mtime) def list_all(self, path=''): """Return all files for a given path""" if path: path = self._get_valid_path(path) if path and not path.endswith('/'): path += '/' # XXX make generator, add start, end return [ blob.name for blob in self.client.list_blobs( name_starts_with=path, timeout=self.timeout)] def listdir(self, path=''): """ Return directories and files for a given path. Leave the path empty to list the root. Order of dirs and files is undefined. """ files = [] dirs = set() for name in self.list_all(path): n = name[len(path):] if '/' in n: dirs.add(n.split('/', 1)[0]) else: files.append(n) return list(dirs), files def get_name_max_len(self): max_len = _AZURE_NAME_MAX_LEN - len(self._get_valid_path('foo')) - len('foo') if not self.overwrite_files: max_len -= len('_1234567') return max_len