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evennia/evennia/contrib/django/aws_s3_cdn.py
trhr 28e4219e76 Refactored and fixed tests
2020-04-10 00:20:59 -05:00

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"""
AWS Storage System
The Right Honourable Reverend (trhr) 2020
ABOUT THIS PLUGIN:
This plugin migrates the Web-based portion of Evennia, namely images,
javascript, and other items located inside staticfiles into Amazon AWS (S3) for hosting.
Files hosted on S3 are "in the cloud," and while your personal
server may be sufficient for serving multimedia to a minimal number of users,
the perfect use case for this plugin would be:
1) Servers supporting heavy web-based traffic (webclient, etc)
2) With a sizable number of users
3) Where the users are globally distributed
4) Where multimedia files are served to users as a part of gameplay
Bottom line - if you're sending an image to a player every time they traverse a
map, the bandwidth reduction will be substantial. If not, probably skip
this one.
Note that storing and serving files via S3 is not technically free outside of
Amazon's "free tier" offering, which you may or may not be eligible for;
evennia's base install currently requires 1.5MB of storage space on S3,
making the current total cost to install this plugin ~$0.0005 per year. If
you have substantial media assets and intend to serve them to many users,
caveat emptor on a total cost of ownership - check AWS's pricing structure.
TECHNICAL DETAILS:
This is a drop-in replacement that operates deeper than all of Evennia's code,
so your existing code does not need to change at all to support it.
For example, when Evennia (or Django), tries to save a file permanently
(say, an image uploaded by a user), the save (or load) communication follows the path:
Evennia -> Django
Django -> Storage backend
Storage backend -> file storage location (e.g. hard drive)
https://docs.djangoproject.com/en/3.0/ref/settings/#std:setting-STATICFILES_STORAGE
This plugin, when enabled, overrides the default storage backend,
which defaults to saving files at mygame/website/, instead,
sending the files to S3 via the storage backend defined herein.
There is no way (or need) to directly access or use the functions here with
other contributions or custom code. Simply work how you would normally, Django
will handle the rest.
INSTALLATION:
1) If you don't have an AWS S3 account, you should create one at
https://aws.amazon.com/ - documentation for AWS S3 is available at:
https://docs.aws.amazon.com/AmazonS3/latest/gsg/GetStartedWithS3.html
Credentials required within the app are AWS IAM Access Key and Secret Keys,
which can be generated/found in the AWS Console.
The following example IAM Control Policy Permissions can be added to
the IAM service inside AWS. Documentation for this can be found here:
https://docs.aws.amazon.com/IAM/latest/UserGuide/introduction.html
Note that this is only required if you want to tightly secure the roles
that this plugin has access to.
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "evennia",
"Effect": "Allow",
"Action": [
"s3:PutObject",
"s3:GetObjectAcl",
"s3:GetObject",
"s3:ListBucket",
"s3:DeleteObject",
"s3:PutObjectAcl"
],
"Resource": [
"arn:aws:s3:::YOUR_BUCKET_NAME/*",
"arn:aws:s3:::YOUR_BUCKET_NAME"
]
}
],
[
{
"Sid":"evennia",
"Effect":"Allow",
"Action":[
"s3:CreateBucket",
],
"Resource":[
"arn:aws:s3:::*"
]
}
]
}
Advanced Users: The second IAM statement, CreateBucket, is only needed
for initial installation. You can remove it later, or you can
create the bucket and set the ACL yourself before you continue.
2) This package requires the dependency "boto3 >= 1.4.4" the official
AWS python package. You can install it with 'pip install boto3'
while inside your evennia virtual environment (or, simply
in your shell if you don't use a virtual environment).
3) Customize the variables defined below in secret_settings.py,
then run 'evennia reboot.' No further configuration is needed.
4) Confirm that web assets are being served from S3 by visiting your
website, then checking the source of any image (for instance, the logo).
It should read https://your-bucket-name.s3.amazonaws.com/path/to/file
START OF SECRET_SETTINGS.PY COPY/PASTE >>>
AWS_ACCESS_KEY_ID = 'THIS_IS_PROVIDED_BY_AMAZON'
AWS_SECRET_ACCESS_KEY = 'THIS_IS_PROVIDED_BY_AMAZON'
AWS_STORAGE_BUCKET_NAME = 'mygame-evennia' # CHANGE ME! I suggest yourgamename-evennia
The settings below need to go in secret_settings,py as well, but will
not need customization unless you want to do something particularly fancy.
AWS_S3_REGION_NAME = 'us-east-1' # N. Virginia
AWS_S3_OBJECT_PARAMETERS = { 'Expires': 'Thu, 31 Dec 2099 20:00:00 GMT',
'CacheControl': 'max-age=94608000', }
AWS_DEFAULT_ACL = 'public-read'
AWS_S3_CUSTOM_DOMAIN = '%s.s3.amazonaws.com' % settings.AWS_BUCKET_NAME
AWS_AUTO_CREATE_BUCKET = True
STATICFILES_STORAGE = 'evennia.contrib.django.aws-s3-cdn.S3Boto3Storage'
<<< END OF SECRET_SETTINGS.PY COPY/PASTE
You may also store these keys as environment variables of the same name.
For advanced configuration, refer to the docs for django-storages.
UNINSTALLATION:
If you haven't made changes to your static files (uploaded images, etc),
you can simply remove the lines you added to secret_settings.py. If you
have made changes and want to uninstall at a later date, you can export
your files from your S3 bucket and put them in /static/ in the evennia
directory.
LICENSE:
Draws heavily from code provided by django-storages, for which these contributors
are authors:
Marty Alchin (S3)
David Larlet (S3)
Arne Brodowski (S3)
Sebastian Serrano (S3)
Andrew McClain (MogileFS)
Rafal Jonca (FTP)
Chris McCormick (S3 with Boto)
Ivanov E. (Database)
Ariel Núñez (packaging)
Wim Leers (SymlinkOrCopy + patches)
Michael Elsdörfer (Overwrite + PEP8 compatibility)
Christian Klein (CouchDB)
Rich Leland (Mosso Cloud Files)
Jason Christa (patches)
Adam Nelson (patches)
Erik CW (S3 encryption)
Axel Gembe (Hash path)
Waldemar Kornewald (MongoDB)
Russell Keith-Magee (Apache LibCloud patches)
Jannis Leidel (S3 and GS with Boto)
Andrei Coman (Azure)
Chris Streeter (S3 with Boto)
Josh Schneier (Fork maintainer, Bugfixes, Py3K)
Anthony Monthe (Dropbox)
EunPyo (Andrew) Hong (Azure)
Michael Barrientos (S3 with Boto3)
piglei (patches)
Matt Braymer-Hayes (S3 with Boto3)
Eirik Martiniussen Sylliaas (Google Cloud Storage native support)
Jody McIntyre (Google Cloud Storage native support)
Stanislav Kaledin (Bug fixes in SFTPStorage)
Filip Vavera (Google Cloud MIME types support)
Max Malysh (Dropbox large file support)
Scott White (Google Cloud updates)
Alex Watt (Google Cloud Storage patch)
Jumpei Yoshimura (S3 docs)
Jon Dufresne
Rodrigo Gadea (Dropbox fixes)
Martey Dodoo
Chris Rink
Shaung Cheng (S3 docs)
Andrew Perry (Bug fixes in SFTPStorage)
The repurposed code from django-storages is released under BSD 3-Clause,
same as Evennia, so for detailed licensing, refer to the Evennia license.
VERSIONING:
This is confirmed to work for Django 2 and Django 3.
'
"""
from django.core.exceptions import (
ImproperlyConfigured,
SuspiciousOperation,
SuspiciousFileOperation,
)
try:
from django.conf import settings as ev_settings
if (
not ev_settings.AWS_ACCESS_KEY_ID
or not ev_settings.AWS_SECRET_ACCESS_KEY
or not ev_settings.AWS_STORAGE_BUCKET_NAME
or not ev_settings.AWS_S3_REGION_NAME
):
raise ImproperlyConfigured(
(
"You must add AWS-specific settings"
"to mygame/server/conf/secret_settings.py to use this plugin."
)
)
if "mygame-evennia" == ev_settings.AWS_STORAGE_BUCKET_NAME:
raise ImproperlyConfigured(
(
"You must customize your AWS_STORAGE_BUCKET_NAME"
"in mygame/server/conf/secret_settings.py;"
"it must be unique among ALL other S3 users"
)
)
except Exception as e:
print(e)
import io
import mimetypes
import os
import posixpath
import threading
from gzip import GzipFile
from tempfile import SpooledTemporaryFile
from django.core.files.base import File
from django.core.files.storage import Storage
from django.utils.deconstruct import deconstructible
from django.utils.encoding import filepath_to_uri, force_bytes, force_text, smart_text
from django.utils.timezone import is_naive, make_naive
try:
from django.utils.six.moves.urllib import parse as urlparse
except ImportError:
from urllib import parse as urlparse
try:
import boto3.session
from boto3 import __version__ as boto3_version
from botocore.client import Config
from botocore.exceptions import ClientError
except ImportError as e:
raise ImproperlyConfigured("Couldn't load S3 bindings. %s Did you run 'pip install boto3?'" % e)
boto3_version_info = tuple([int(i) for i in boto3_version.split(".")])
def setting(name, default=None):
"""
Helper function to get a Django setting by name. If setting doesn't exist
it will return a default.
Args:
name (str): A Django setting name
Returns:
The value of the setting variable by that name
"""
return getattr(ev_settings, name, default)
def safe_join(base, *paths):
"""
Helper function, a version of django.utils._os.safe_join for S3 paths.
Joins one or more path components to the base path component
intelligently. Returns a normalized version of the final path.
The final path must be located inside of the base path component
(otherwise a ValueError is raised). Paths outside the base path
indicate a possible security sensitive operation.
Args:
base (str): A path string to the base of the staticfiles
*paths (list): A list of paths as referenced from the base path
Returns:
final_path (str): A joined path, base + filepath
"""
base_path = force_text(base)
base_path = base_path.rstrip("/")
paths = [force_text(p) for p in paths]
final_path = base_path + "/"
for path in paths:
_final_path = posixpath.normpath(posixpath.join(final_path, path))
# posixpath.normpath() strips the trailing /. Add it back.
if path.endswith("/") or _final_path + "/" == final_path:
_final_path += "/"
final_path = _final_path
if final_path == base_path:
final_path += "/"
# Ensure final_path starts with base_path and that the next character after
# the base path is /.
base_path_len = len(base_path)
if not final_path.startswith(base_path) or final_path[base_path_len] != "/":
raise ValueError("the joined path is located outside of the base path" " component")
return final_path.lstrip("/")
def check_location(storage):
"""
Helper function to make sure that the storage location is configured correctly.
Args:
storage (Storage): A Storage object (Django)
Raises:
ImproperlyConfigured: If the storage location is not configured correctly,
this is raised.
"""
if storage.location.startswith("/"):
correct = storage.location.lstrip("/")
raise ImproperlyConfigured(
"{}.location cannot begin with a leading slash. Found '{}'. Use '{}' instead.".format(
storage.__class__.__name__, storage.location, correct,
)
)
def lookup_env(names):
"""
Helper function for looking up names in env vars. Returns the first element found.
Args:
names (str): A list of environment variables
Returns:
value (str): The value of the found environment variable.
"""
for name in names:
value = os.environ.get(name)
if value:
return value
def get_available_overwrite_name(name, max_length):
"""
Helper function indicating files that will be overwritten during trunc.
Args:
name (str): The name of the file
max_length (int): The maximum length of a filename
Returns:
joined (path): A joined path including directory, file, and extension
"""
if max_length is None or len(name) <= max_length:
return name
# Adapted from Django
dir_name, file_name = os.path.split(name)
file_root, file_ext = os.path.splitext(file_name)
truncation = len(name) - max_length
file_root = file_root[:-truncation]
if not file_root:
raise SuspiciousFileOperation(
'aws-s3-cdn tried to truncate away entire filename "%s". '
"Please make sure that the corresponding file field "
'allows sufficient "max_length".' % name
)
return os.path.join(dir_name, "{}{}".format(file_root, file_ext))
@deconstructible
class S3Boto3StorageFile(File):
"""
The default file object used by the S3Boto3Storage backend.
This file implements file streaming using boto's multipart
uploading functionality. The file can be opened in read or
write mode.
This class extends Django's File class. However, the contained
data is only the data contained in the current buffer. So you
should not access the contained file object directly. You should
access the data via this class.
Warning: This file *must* be closed using the close() method in
order to properly write the file to S3. Be sure to close the file
in your application.
"""
buffer_size = setting("AWS_S3_FILE_BUFFER_SIZE", 5242880)
def __init__(self, name, mode, storage, buffer_size=None):
"""
Initializes the File object.
Args:
name (str): The name of the file
mode (str): The access mode ('r' or 'w')
storage (Storage): The Django Storage object
buffer_size (int): The buffer size, for multipart uploads
"""
if "r" in mode and "w" in mode:
raise ValueError("Can't combine 'r' and 'w' in mode.")
self._storage = storage
self.name = name[len(self._storage.location):].lstrip("/")
self._mode = mode
self._force_mode = (lambda b: b) if "b" in mode else force_text
self.obj = storage.bucket.Object(storage._encode_name(name))
if "w" not in mode:
# Force early RAII-style exception if object does not exist
self.obj.load()
self._is_dirty = False
self._raw_bytes_written = 0
self._file = None
self._multipart = None
# 5 MB is the minimum part size (if there is more than one part).
# Amazon allows up to 10,000 parts. The default supports uploads
# up to roughly 50 GB. Increase the part size to accommodate
# for files larger than this.
if buffer_size is not None:
self.buffer_size = buffer_size
self._write_counter = 0
@property
def size(self):
"""
Helper property to return filesize
"""
return self.obj.content_length
def _get_file(self):
"""
Helper function to manage zipping and temporary files
"""
if self._file is None:
self._file = SpooledTemporaryFile(
max_size=self._storage.max_memory_size,
suffix=".S3Boto3StorageFile",
dir=setting("FILE_UPLOAD_TEMP_DIR"),
)
if "r" in self._mode:
self._is_dirty = False
self.obj.download_fileobj(self._file)
self._file.seek(0)
if self._storage.gzip and self.obj.content_encoding == "gzip":
self._file = GzipFile(mode=self._mode, fileobj=self._file, mtime=0.0)
return self._file
def _set_file(self, value):
self._file = value
file = property(_get_file, _set_file)
def read(self, *args, **kwargs):
"""
Checks if file is in read mode; then continues to boto3 operation
"""
if "r" not in self._mode:
raise AttributeError("File was not opened in read mode.")
return self._force_mode(super().read(*args, **kwargs))
def readline(self, *args, **kwargs):
"""
Checks if file is in read mode; then continues to boto3 operation
"""
if "r" not in self._mode:
raise AttributeError("File was not opened in read mode.")
return self._force_mode(super().readline(*args, **kwargs))
def write(self, content):
"""
Checks if file is in write mode or needs multipart handling,
then continues to boto3 operation.
"""
if "w" not in self._mode:
raise AttributeError("File was not opened in write mode.")
self._is_dirty = True
if self._multipart is None:
self._multipart = self.obj.initiate_multipart_upload(
**self._storage._get_write_parameters(self.obj.key)
)
if self.buffer_size <= self._buffer_file_size:
self._flush_write_buffer()
bstr = force_bytes(content)
self._raw_bytes_written += len(bstr)
return super().write(bstr)
@property
def _buffer_file_size(self):
pos = self.file.tell()
self.file.seek(0, os.SEEK_END)
length = self.file.tell()
self.file.seek(pos)
return length
def _flush_write_buffer(self):
"""
Flushes the write buffer.
"""
if self._buffer_file_size:
self._write_counter += 1
self.file.seek(0)
part = self._multipart.Part(self._write_counter)
part.upload(Body=self.file.read())
self.file.seek(0)
self.file.truncate()
def _create_empty_on_close(self):
"""
Attempt to create an empty file for this key when this File is closed if no bytes
have been written and no object already exists on S3 for this key.
This behavior is meant to mimic the behavior of Django's builtin FileSystemStorage,
where files are always created after they are opened in write mode:
f = storage.open("file.txt", mode="w")
f.close()
Raises:
Exception: Raised if a 404 error occurs
"""
assert "w" in self._mode
assert self._raw_bytes_written == 0
try:
# Check if the object exists on the server; if so, don't do anything
self.obj.load()
except ClientError as err:
if err.response["ResponseMetadata"]["HTTPStatusCode"] == 404:
self.obj.put(Body=b"", **self._storage._get_write_parameters(self.obj.key))
else:
raise
def close(self):
"""
Manages file closing after multipart uploads
"""
if self._is_dirty:
self._flush_write_buffer()
parts = [
{"ETag": part.e_tag, "PartNumber": part.part_number}
for part in self._multipart.parts.all()
]
self._multipart.complete(MultipartUpload={"Parts": parts})
else:
if self._multipart is not None:
self._multipart.abort()
if "w" in self._mode and self._raw_bytes_written == 0:
self._create_empty_on_close()
if self._file is not None:
self._file.close()
self._file = None
@deconstructible
class S3Boto3Storage(Storage):
"""
Amazon Simple Storage Service using Boto3
This storage backend supports opening files in read or write
mode and supports streaming(buffering) data in chunks to S3
when writing.
"""
default_content_type = "application/octet-stream"
# If config provided in init, signature_version and addressing_style settings/args are ignored.
config = None
# used for looking up the access and secret key from env vars
access_key_names = ["AWS_S3_ACCESS_KEY_ID", "AWS_ACCESS_KEY_ID"]
secret_key_names = ["AWS_S3_SECRET_ACCESS_KEY", "AWS_SECRET_ACCESS_KEY"]
security_token_names = ["AWS_SESSION_TOKEN", "AWS_SECURITY_TOKEN"]
security_token = None
access_key = setting("AWS_S3_ACCESS_KEY_ID", setting("AWS_ACCESS_KEY_ID", ""))
secret_key = setting("AWS_S3_SECRET_ACCESS_KEY", setting("AWS_SECRET_ACCESS_KEY", ""))
file_overwrite = setting("AWS_S3_FILE_OVERWRITE", True)
object_parameters = setting("AWS_S3_OBJECT_PARAMETERS", {})
bucket_name = setting("AWS_STORAGE_BUCKET_NAME")
auto_create_bucket = setting("AWS_AUTO_CREATE_BUCKET", False)
default_acl = setting("AWS_DEFAULT_ACL", "public-read")
bucket_acl = setting("AWS_BUCKET_ACL", default_acl)
querystring_auth = setting("AWS_QUERYSTRING_AUTH", True)
querystring_expire = setting("AWS_QUERYSTRING_EXPIRE", 3600)
signature_version = setting("AWS_S3_SIGNATURE_VERSION")
reduced_redundancy = setting("AWS_REDUCED_REDUNDANCY", False)
location = setting("AWS_LOCATION", "")
encryption = setting("AWS_S3_ENCRYPTION", False)
custom_domain = setting("AWS_S3_CUSTOM_DOMAIN")
addressing_style = setting("AWS_S3_ADDRESSING_STYLE")
secure_urls = setting("AWS_S3_SECURE_URLS", True)
file_name_charset = setting("AWS_S3_FILE_NAME_CHARSET", "utf-8")
gzip = setting("AWS_IS_GZIPPED", False)
preload_metadata = setting("AWS_PRELOAD_METADATA", False)
gzip_content_types = setting(
"GZIP_CONTENT_TYPES",
(
"text/css",
"text/javascript",
"application/javascript",
"application/x-javascript",
"image/svg+xml",
),
)
url_protocol = setting("AWS_S3_URL_PROTOCOL", "http:")
endpoint_url = setting("AWS_S3_ENDPOINT_URL")
proxies = setting("AWS_S3_PROXIES")
region_name = setting("AWS_S3_REGION_NAME")
use_ssl = setting("AWS_S3_USE_SSL", True)
verify = setting("AWS_S3_VERIFY", None)
max_memory_size = setting("AWS_S3_MAX_MEMORY_SIZE", 0)
def __init__(self, acl=None, bucket=None, **settings):
"""
Check if some of the settings we've provided as class attributes
need to be overwritten with values passed in here.
"""
for name, value in settings.items():
if hasattr(self, name):
setattr(self, name, value)
check_location(self)
# Backward-compatibility: given the anteriority of the SECURE_URL setting
# we fall back to https if specified in order to avoid the construction
# of unsecure urls.
if self.secure_urls:
self.url_protocol = "https:"
self._entries = {}
self._bucket = None
self._connections = threading.local()
self.access_key, self.secret_key = self._get_access_keys()
self.security_token = self._get_security_token()
if not self.config:
kwargs = dict(
s3={"addressing_style": self.addressing_style},
signature_version=self.signature_version,
)
if boto3_version_info >= (1, 4, 4):
kwargs["proxies"] = self.proxies
self.config = Config(**kwargs)
def __getstate__(self):
state = self.__dict__.copy()
state.pop("_connections", None)
state.pop("_bucket", None)
return state
def __setstate__(self, state):
state["_connections"] = threading.local()
state["_bucket"] = None
self.__dict__ = state
@property
def connection(self):
"""
Creates the actual connection to S3
"""
connection = getattr(self._connections, "connection", None)
if connection is None:
session = boto3.session.Session()
self._connections.connection = session.resource(
"s3",
aws_access_key_id=self.access_key,
aws_secret_access_key=self.secret_key,
aws_session_token=self.security_token,
region_name=self.region_name,
use_ssl=self.use_ssl,
endpoint_url=self.endpoint_url,
config=self.config,
verify=self.verify,
)
return self._connections.connection
@property
def bucket(self):
"""
Get the current bucket. If there is no current bucket object
create it.
"""
if self._bucket is None:
self._bucket = self._get_or_create_bucket(self.bucket_name)
return self._bucket
@property
def entries(self):
"""
Get the locally cached files for the bucket.
"""
if self.preload_metadata and not self._entries:
self._entries = {
self._decode_name(entry.key): entry
for entry in self.bucket.objects.filter(Prefix=self.location)
}
return self._entries
def _get_access_keys(self):
"""
Gets the access keys to use when accessing S3. If none is
provided in the settings then get them from the environment
variables.
"""
access_key = self.access_key or lookup_env(S3Boto3Storage.access_key_names)
secret_key = self.secret_key or lookup_env(S3Boto3Storage.secret_key_names)
return access_key, secret_key
def _get_security_token(self):
"""
Gets the security token to use when accessing S3. Get it from
the environment variables.
"""
security_token = self.security_token or lookup_env(S3Boto3Storage.security_token_names)
return security_token
def _get_or_create_bucket(self, name):
"""
Retrieves a bucket if it exists, otherwise creates it.
"""
bucket = self.connection.Bucket(name)
if self.auto_create_bucket:
try:
# Directly call head_bucket instead of bucket.load() because head_bucket()
# fails on wrong region, while bucket.load() does not.
bucket.meta.client.head_bucket(Bucket=name)
except ClientError as err:
if err.response["ResponseMetadata"]["HTTPStatusCode"] == 301:
raise ImproperlyConfigured(
"Bucket %s exists, but in a different "
"region than we are connecting to. Set "
"the region to connect to by setting "
"AWS_S3_REGION_NAME to the correct region." % name
)
elif err.response["ResponseMetadata"]["HTTPStatusCode"] == 404:
# Notes: When using the us-east-1 Standard endpoint, you can create
# buckets in other regions. The same is not true when hitting region specific
# endpoints. However, when you create the bucket not in the same region, the
# connection will fail all future requests to the Bucket after the creation
# (301 Moved Permanently).
#
# For simplicity, we enforce in S3Boto3Storage that any auto-created
# bucket must match the region that the connection is for.
#
# Also note that Amazon specifically disallows "us-east-1" when passing bucket
# region names; LocationConstraint *must* be blank to create in US Standard.
if self.bucket_acl:
bucket_params = {"ACL": self.bucket_acl}
else:
bucket_params = {}
region_name = self.connection.meta.client.meta.region_name
if region_name != "us-east-1":
bucket_params["CreateBucketConfiguration"] = {
"LocationConstraint": region_name
}
bucket.create(**bucket_params)
else:
raise
return bucket
def _clean_name(self, name):
"""
Cleans the name so that Windows style paths work
"""
# Normalize Windows style paths
clean_name = posixpath.normpath(name).replace("\\", "/")
# os.path.normpath() can strip trailing slashes so we implement
# a workaround here.
if name.endswith("/") and not clean_name.endswith("/"):
# Add a trailing slash as it was stripped.
clean_name += "/"
return clean_name
def _normalize_name(self, name):
"""
Normalizes the name so that paths like /path/to/ignored/../something.txt
work. We check to make sure that the path pointed to is not outside
the directory specified by the LOCATION setting.
"""
try:
return safe_join(self.location, name)
except ValueError:
raise SuspiciousOperation("Attempted access to '%s' denied." % name)
def _encode_name(self, name):
return smart_text(name, encoding=self.file_name_charset)
def _decode_name(self, name):
return force_text(name, encoding=self.file_name_charset)
def _compress_content(self, content):
"""Gzip a given string content."""
content.seek(0)
zbuf = io.BytesIO()
# The GZIP header has a modification time attribute (see http://www.zlib.org/rfc-gzip.html)
# Each time a file is compressed it changes even if the other contents don't change
# For S3 this defeats detection of changes using MD5 sums on gzipped files
# Fixing the mtime at 0.0 at compression time avoids this problem
zfile = GzipFile(mode="wb", fileobj=zbuf, mtime=0.0)
try:
zfile.write(force_bytes(content.read()))
finally:
zfile.close()
zbuf.seek(0)
# Boto 2 returned the InMemoryUploadedFile with the file pointer replaced,
# but Boto 3 seems to have issues with that. No need for fp.name in Boto3
# so just returning the BytesIO directly
return zbuf
def _open(self, name, mode="rb"):
"""
Opens the file, if it exists.
"""
name = self._normalize_name(self._clean_name(name))
try:
f = S3Boto3StorageFile(name, mode, self)
except ClientError as err:
if err.response["ResponseMetadata"]["HTTPStatusCode"] == 404:
raise IOError("File does not exist: %s" % name)
raise # Let it bubble up if it was some other error
return f
def _save(self, name, content):
"""
Stitches and cleans multipart uploads; normalizes file paths.
"""
cleaned_name = self._clean_name(name)
name = self._normalize_name(cleaned_name)
params = self._get_write_parameters(name, content)
if (
self.gzip
and params["ContentType"] in self.gzip_content_types
and "ContentEncoding" not in params
):
content = self._compress_content(content)
params["ContentEncoding"] = "gzip"
encoded_name = self._encode_name(name)
obj = self.bucket.Object(encoded_name)
if self.preload_metadata:
self._entries[encoded_name] = obj
content.seek(0, os.SEEK_SET)
obj.upload_fileobj(content, ExtraArgs=params)
return cleaned_name
def delete(self, name):
"""
Deletes a file from S3.
"""
name = self._normalize_name(self._clean_name(name))
self.bucket.Object(self._encode_name(name)).delete()
if name in self._entries:
del self._entries[name]
def exists(self, name):
"""
Checks if file exists.
"""
name = self._normalize_name(self._clean_name(name))
if self.entries:
return name in self.entries
try:
self.connection.meta.client.head_object(Bucket=self.bucket_name, Key=name)
return True
except ClientError:
return False
def listdir(self, name):
"""
Translational function to go from S3 file paths to the format
Django's listdir expects.
"""
path = self._normalize_name(self._clean_name(name))
# The path needs to end with a slash, but if the root is empty, leave
# it.
if path and not path.endswith("/"):
path += "/"
directories = []
files = []
paginator = self.connection.meta.client.get_paginator("list_objects")
pages = paginator.paginate(Bucket=self.bucket_name, Delimiter="/", Prefix=path)
for page in pages:
for entry in page.get("CommonPrefixes", ()):
directories.append(posixpath.relpath(entry["Prefix"], path))
for entry in page.get("Contents", ()):
files.append(posixpath.relpath(entry["Key"], path))
return directories, files
def size(self, name):
"""
Gets the filesize of a remote file.
"""
name = self._normalize_name(self._clean_name(name))
if self.entries:
entry = self.entries.get(name)
if entry:
return entry.size if hasattr(entry, "size") else entry.content_length
return 0
return self.bucket.Object(self._encode_name(name)).content_length
def _get_write_parameters(self, name, content=None):
params = {}
if self.encryption:
params["ServerSideEncryption"] = "AES256"
if self.reduced_redundancy:
params["StorageClass"] = "REDUCED_REDUNDANCY"
if self.default_acl:
params["ACL"] = self.default_acl
_type, encoding = mimetypes.guess_type(name)
content_type = getattr(content, "content_type", None)
content_type = content_type or _type or self.default_content_type
params["ContentType"] = content_type
if encoding:
params["ContentEncoding"] = encoding
params.update(self.get_object_parameters(name))
return params
def get_object_parameters(self, name):
"""
Returns a dictionary that is passed to file upload. Override this
method to adjust this on a per-object basis to set e.g ContentDisposition.
By default, returns the value of AWS_S3_OBJECT_PARAMETERS.
Setting ContentEncoding will prevent objects from being automatically gzipped.
"""
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.
"""
name = self._normalize_name(self._clean_name(name))
entry = self.entries.get(name)
# only call self.bucket.Object() if the key is not found
# in the preloaded metadata.
if entry is None:
entry = self.bucket.Object(self._encode_name(name))
if setting("USE_TZ"):
# boto3 returns TZ aware timestamps
return entry.last_modified
else:
return make_naive(entry.last_modified)
def modified_time(self, name):
"""Returns a naive datetime object containing the last modified time.
If USE_TZ=False then get_modified_time will return a naive datetime
so we just return that, else we have to localize and strip the tz
"""
mtime = self.get_modified_time(name)
return mtime if is_naive(mtime) else make_naive(mtime)
def _strip_signing_parameters(self, url):
"""
Boto3 does not currently support generating URLs that are unsigned. Instead we
take the signed URLs and strip any querystring params related to signing and expiration.
Note that this may end up with URLs that are still invalid, especially if params are
passed in that only work with signed URLs, e.g. response header params.
The code attempts to strip all query parameters that match names of known parameters
from v2 and v4 signatures, regardless of the actual signature version used.
"""
split_url = urlparse.urlsplit(url)
qs = urlparse.parse_qsl(split_url.query, keep_blank_values=True)
blacklist = {
"x-amz-algorithm",
"x-amz-credential",
"x-amz-date",
"x-amz-expires",
"x-amz-signedheaders",
"x-amz-signature",
"x-amz-security-token",
"awsaccesskeyid",
"expires",
"signature",
}
filtered_qs = ((key, val) for key, val in qs if key.lower() not in blacklist)
# Note: Parameters that did not have a value in the original query string will have
# an '=' sign appended to it, e.g ?foo&bar becomes ?foo=&bar=
joined_qs = ("=".join(keyval) for keyval in filtered_qs)
split_url = split_url._replace(query="&".join(joined_qs))
return split_url.geturl()
def url(self, name, parameters=None, expire=None):
"""
Returns the URL of a remotely-hosted file
"""
# Preserve the trailing slash after normalizing the path.
name = self._normalize_name(self._clean_name(name))
if self.custom_domain:
return "{}//{}/{}".format(self.url_protocol, self.custom_domain, filepath_to_uri(name))
if expire is None:
expire = self.querystring_expire
params = parameters.copy() if parameters else {}
params["Bucket"] = self.bucket.name
params["Key"] = self._encode_name(name)
url = self.bucket.meta.client.generate_presigned_url(
"get_object", Params=params, ExpiresIn=expire
)
if self.querystring_auth:
return url
return self._strip_signing_parameters(url)
def get_available_name(self, name, max_length=None):
"""Overwrite existing file with the same name."""
name = self._clean_name(name)
if self.file_overwrite:
return get_available_overwrite_name(name, max_length)
return super().get_available_name(name, max_length)
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