| # Copyright 2016 The Chromium Authors. All rights reserved. |
| # Use of this source code is govered by a BSD-style |
| # license that can be found in the LICENSE file or at |
| # https://developers.google.com/open-source/licenses/bsd |
| |
| """Set of helpers for interacting with Google Cloud Storage.""" |
| |
| import base64 |
| import logging |
| import os |
| import time |
| import urllib |
| import uuid |
| |
| from datetime import datetime, timedelta |
| |
| from google.appengine.api import app_identity |
| from google.appengine.api import images |
| from third_party import cloudstorage |
| |
| from framework import filecontent |
| |
| |
| ATTACHMENT_TTL = timedelta(seconds=30) |
| |
| IS_DEV_APPSERVER = ( |
| 'development' in os.environ.get('SERVER_SOFTWARE', '').lower()) |
| |
| RESIZABLE_MIME_TYPES = ['image/png', 'image/jpg', 'image/jpeg', 'image/gif'] |
| |
| DEFAULT_THUMB_WIDTH = 250 |
| DEFAULT_THUMB_HEIGHT = 200 |
| LOGO_THUMB_WIDTH = 110 |
| LOGO_THUMB_HEIGHT = 30 |
| |
| |
| def _Now(): |
| return datetime.utcnow() |
| |
| |
| class UnsupportedMimeType(Exception): |
| pass |
| |
| |
| def DeleteObjectFromGCS(object_id): |
| object_path = ('/' + app_identity.get_default_gcs_bucket_name() + object_id) |
| cloudstorage.delete(object_path) |
| |
| |
| def StoreObjectInGCS( |
| content, mime_type, project_id, thumb_width=DEFAULT_THUMB_WIDTH, |
| thumb_height=DEFAULT_THUMB_HEIGHT): |
| bucket_name = app_identity.get_default_gcs_bucket_name() |
| guid = uuid.uuid4() |
| object_id = '/%s/attachments/%s' % (project_id, guid) |
| object_path = '/' + bucket_name + object_id |
| with cloudstorage.open(object_path, 'w', mime_type) as f: |
| f.write(content) |
| |
| if mime_type in RESIZABLE_MIME_TYPES: |
| # Create and save a thumbnail too. |
| thumb_content = None |
| try: |
| thumb_content = images.resize(content, thumb_width, thumb_height) |
| except Exception, e: |
| # Do not raise exception for incorrectly formed images. |
| # See https://bugs.chromium.org/p/monorail/issues/detail?id=597 for more |
| # detail. |
| logging.exception(e) |
| if thumb_content: |
| thumb_path = '%s-thumbnail' % object_path |
| with cloudstorage.open(thumb_path, 'w', 'image/png') as f: |
| f.write(thumb_content) |
| |
| return object_id |
| |
| |
| def CheckMimeTypeResizable(mime_type): |
| if mime_type not in RESIZABLE_MIME_TYPES: |
| raise UnsupportedMimeType( |
| 'Please upload a logo with one of the following mime types:\n%s' % |
| ', '.join(RESIZABLE_MIME_TYPES)) |
| |
| |
| def StoreLogoInGCS(file_name, content, project_id): |
| mime_type = filecontent.GuessContentTypeFromFilename(file_name) |
| CheckMimeTypeResizable(mime_type) |
| if '\\' in file_name: # IE insists on giving us the whole path. |
| file_name = file_name[file_name.rindex('\\') + 1:] |
| return StoreObjectInGCS( |
| content, mime_type, project_id, thumb_width=LOGO_THUMB_WIDTH, |
| thumb_height=LOGO_THUMB_HEIGHT) |
| |
| |
| def SignUrl(gcs_filename): |
| expiration_dt = _Now() + ATTACHMENT_TTL |
| expiration = int(time.mktime(expiration_dt.timetuple())) |
| signature_string = '\n'.join([ |
| 'GET', |
| '', # Optional MD5, which we don't have. |
| '', # Optional content-type, which only applies to uploads. |
| str(expiration), |
| gcs_filename]).encode('utf-8') |
| |
| signature_bytes = app_identity.sign_blob(signature_string)[1] |
| |
| query_params = {'GoogleAccessId': app_identity.get_service_account_name(), |
| 'Expires': str(expiration), |
| 'Signature': base64.b64encode(signature_bytes)} |
| |
| result = 'https://storage.googleapis.com{resource}?{querystring}' |
| |
| if IS_DEV_APPSERVER: |
| result = '/_ah/gcs{resource}?{querystring}' |
| |
| return result.format( |
| resource=gcs_filename, querystring=urllib.urlencode(query_params)) |
| |