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mirror of https://github.com/scrapy/scrapy.git synced 2025-03-14 16:28:31 +00:00
2020-04-23 12:40:10 +02:00

533 lines
20 KiB
Python

"""
Files Pipeline
See documentation in topics/media-pipeline.rst
"""
import functools
import hashlib
import logging
import mimetypes
import os
import time
from collections import defaultdict
from email.utils import parsedate_tz, mktime_tz
from ftplib import FTP
from io import BytesIO
from urllib.parse import urlparse
from twisted.internet import defer, threads
from scrapy.pipelines.media import MediaPipeline
from scrapy.settings import Settings
from scrapy.exceptions import NotConfigured, IgnoreRequest
from scrapy.http import Request
from scrapy.utils.misc import md5sum
from scrapy.utils.log import failure_to_exc_info
from scrapy.utils.python import to_bytes
from scrapy.utils.request import referer_str
from scrapy.utils.boto import is_botocore
from scrapy.utils.datatypes import CaselessDict
from scrapy.utils.ftp import ftp_store_file
logger = logging.getLogger(__name__)
class FileException(Exception):
"""General media error exception"""
class FSFilesStore:
def __init__(self, basedir):
if '://' in basedir:
basedir = basedir.split('://', 1)[1]
self.basedir = basedir
self._mkdir(self.basedir)
self.created_directories = defaultdict(set)
def persist_file(self, path, buf, info, meta=None, headers=None):
absolute_path = self._get_filesystem_path(path)
self._mkdir(os.path.dirname(absolute_path), info)
with open(absolute_path, 'wb') as f:
f.write(buf.getvalue())
def stat_file(self, path, info):
absolute_path = self._get_filesystem_path(path)
try:
last_modified = os.path.getmtime(absolute_path)
except os.error:
return {}
with open(absolute_path, 'rb') as f:
checksum = md5sum(f)
return {'last_modified': last_modified, 'checksum': checksum}
def _get_filesystem_path(self, path):
path_comps = path.split('/')
return os.path.join(self.basedir, *path_comps)
def _mkdir(self, dirname, domain=None):
seen = self.created_directories[domain] if domain else set()
if dirname not in seen:
if not os.path.exists(dirname):
os.makedirs(dirname)
seen.add(dirname)
class S3FilesStore:
AWS_ACCESS_KEY_ID = None
AWS_SECRET_ACCESS_KEY = None
AWS_ENDPOINT_URL = None
AWS_REGION_NAME = None
AWS_USE_SSL = None
AWS_VERIFY = None
POLICY = 'private' # Overriden from settings.FILES_STORE_S3_ACL in
# FilesPipeline.from_settings.
HEADERS = {
'Cache-Control': 'max-age=172800',
}
def __init__(self, uri):
self.is_botocore = is_botocore()
if self.is_botocore:
import botocore.session
session = botocore.session.get_session()
self.s3_client = session.create_client(
's3',
aws_access_key_id=self.AWS_ACCESS_KEY_ID,
aws_secret_access_key=self.AWS_SECRET_ACCESS_KEY,
endpoint_url=self.AWS_ENDPOINT_URL,
region_name=self.AWS_REGION_NAME,
use_ssl=self.AWS_USE_SSL,
verify=self.AWS_VERIFY
)
else:
from boto.s3.connection import S3Connection
self.S3Connection = S3Connection
if not uri.startswith("s3://"):
raise ValueError("Incorrect URI scheme in %s, expected 's3'" % uri)
self.bucket, self.prefix = uri[5:].split('/', 1)
def stat_file(self, path, info):
def _onsuccess(boto_key):
if self.is_botocore:
checksum = boto_key['ETag'].strip('"')
last_modified = boto_key['LastModified']
modified_stamp = time.mktime(last_modified.timetuple())
else:
checksum = boto_key.etag.strip('"')
last_modified = boto_key.last_modified
modified_tuple = parsedate_tz(last_modified)
modified_stamp = int(mktime_tz(modified_tuple))
return {'checksum': checksum, 'last_modified': modified_stamp}
return self._get_boto_key(path).addCallback(_onsuccess)
def _get_boto_bucket(self):
# disable ssl (is_secure=False) because of this python bug:
# https://bugs.python.org/issue5103
c = self.S3Connection(self.AWS_ACCESS_KEY_ID, self.AWS_SECRET_ACCESS_KEY, is_secure=False)
return c.get_bucket(self.bucket, validate=False)
def _get_boto_key(self, path):
key_name = '%s%s' % (self.prefix, path)
if self.is_botocore:
return threads.deferToThread(
self.s3_client.head_object,
Bucket=self.bucket,
Key=key_name)
else:
b = self._get_boto_bucket()
return threads.deferToThread(b.get_key, key_name)
def persist_file(self, path, buf, info, meta=None, headers=None):
"""Upload file to S3 storage"""
key_name = '%s%s' % (self.prefix, path)
buf.seek(0)
if self.is_botocore:
extra = self._headers_to_botocore_kwargs(self.HEADERS)
if headers:
extra.update(self._headers_to_botocore_kwargs(headers))
return threads.deferToThread(
self.s3_client.put_object,
Bucket=self.bucket,
Key=key_name,
Body=buf,
Metadata={k: str(v) for k, v in (meta or {}).items()},
ACL=self.POLICY,
**extra)
else:
b = self._get_boto_bucket()
k = b.new_key(key_name)
if meta:
for metakey, metavalue in meta.items():
k.set_metadata(metakey, str(metavalue))
h = self.HEADERS.copy()
if headers:
h.update(headers)
return threads.deferToThread(
k.set_contents_from_string, buf.getvalue(),
headers=h, policy=self.POLICY)
def _headers_to_botocore_kwargs(self, headers):
""" Convert headers to botocore keyword agruments.
"""
# This is required while we need to support both boto and botocore.
mapping = CaselessDict({
'Content-Type': 'ContentType',
'Cache-Control': 'CacheControl',
'Content-Disposition': 'ContentDisposition',
'Content-Encoding': 'ContentEncoding',
'Content-Language': 'ContentLanguage',
'Content-Length': 'ContentLength',
'Content-MD5': 'ContentMD5',
'Expires': 'Expires',
'X-Amz-Grant-Full-Control': 'GrantFullControl',
'X-Amz-Grant-Read': 'GrantRead',
'X-Amz-Grant-Read-ACP': 'GrantReadACP',
'X-Amz-Grant-Write-ACP': 'GrantWriteACP',
'X-Amz-Object-Lock-Legal-Hold': 'ObjectLockLegalHoldStatus',
'X-Amz-Object-Lock-Mode': 'ObjectLockMode',
'X-Amz-Object-Lock-Retain-Until-Date': 'ObjectLockRetainUntilDate',
'X-Amz-Request-Payer': 'RequestPayer',
'X-Amz-Server-Side-Encryption': 'ServerSideEncryption',
'X-Amz-Server-Side-Encryption-Aws-Kms-Key-Id': 'SSEKMSKeyId',
'X-Amz-Server-Side-Encryption-Context': 'SSEKMSEncryptionContext',
'X-Amz-Server-Side-Encryption-Customer-Algorithm': 'SSECustomerAlgorithm',
'X-Amz-Server-Side-Encryption-Customer-Key': 'SSECustomerKey',
'X-Amz-Server-Side-Encryption-Customer-Key-Md5': 'SSECustomerKeyMD5',
'X-Amz-Storage-Class': 'StorageClass',
'X-Amz-Tagging': 'Tagging',
'X-Amz-Website-Redirect-Location': 'WebsiteRedirectLocation',
})
extra = {}
for key, value in headers.items():
try:
kwarg = mapping[key]
except KeyError:
raise TypeError(
'Header "%s" is not supported by botocore' % key)
else:
extra[kwarg] = value
return extra
class GCSFilesStore:
GCS_PROJECT_ID = None
CACHE_CONTROL = 'max-age=172800'
# The bucket's default object ACL will be applied to the object.
# Overriden from settings.FILES_STORE_GCS_ACL in FilesPipeline.from_settings.
POLICY = None
def __init__(self, uri):
from google.cloud import storage
client = storage.Client(project=self.GCS_PROJECT_ID)
bucket, prefix = uri[5:].split('/', 1)
self.bucket = client.bucket(bucket)
self.prefix = prefix
def stat_file(self, path, info):
def _onsuccess(blob):
if blob:
checksum = blob.md5_hash
last_modified = time.mktime(blob.updated.timetuple())
return {'checksum': checksum, 'last_modified': last_modified}
else:
return {}
return threads.deferToThread(self.bucket.get_blob, path).addCallback(_onsuccess)
def _get_content_type(self, headers):
if headers and 'Content-Type' in headers:
return headers['Content-Type']
else:
return 'application/octet-stream'
def persist_file(self, path, buf, info, meta=None, headers=None):
blob = self.bucket.blob(self.prefix + path)
blob.cache_control = self.CACHE_CONTROL
blob.metadata = {k: str(v) for k, v in (meta or {}).items()}
return threads.deferToThread(
blob.upload_from_string,
data=buf.getvalue(),
content_type=self._get_content_type(headers),
predefined_acl=self.POLICY
)
class FTPFilesStore:
FTP_USERNAME = None
FTP_PASSWORD = None
USE_ACTIVE_MODE = None
def __init__(self, uri):
if not uri.startswith("ftp://"):
raise ValueError("Incorrect URI scheme in %s, expected 'ftp'" % uri)
u = urlparse(uri)
self.port = u.port
self.host = u.hostname
self.port = int(u.port or 21)
self.username = u.username or self.FTP_USERNAME
self.password = u.password or self.FTP_PASSWORD
self.basedir = u.path.rstrip('/')
def persist_file(self, path, buf, info, meta=None, headers=None):
path = '%s/%s' % (self.basedir, path)
return threads.deferToThread(
ftp_store_file, path=path, file=buf,
host=self.host, port=self.port, username=self.username,
password=self.password, use_active_mode=self.USE_ACTIVE_MODE
)
def stat_file(self, path, info):
def _stat_file(path):
try:
ftp = FTP()
ftp.connect(self.host, self.port)
ftp.login(self.username, self.password)
if self.USE_ACTIVE_MODE:
ftp.set_pasv(False)
file_path = "%s/%s" % (self.basedir, path)
last_modified = float(ftp.voidcmd("MDTM %s" % file_path)[4:].strip())
m = hashlib.md5()
ftp.retrbinary('RETR %s' % file_path, m.update)
return {'last_modified': last_modified, 'checksum': m.hexdigest()}
# The file doesn't exist
except Exception:
return {}
return threads.deferToThread(_stat_file, path)
class FilesPipeline(MediaPipeline):
"""Abstract pipeline that implement the file downloading
This pipeline tries to minimize network transfers and file processing,
doing stat of the files and determining if file is new, uptodate or
expired.
``new`` files are those that pipeline never processed and needs to be
downloaded from supplier site the first time.
``uptodate`` files are the ones that the pipeline processed and are still
valid files.
``expired`` files are those that pipeline already processed but the last
modification was made long time ago, so a reprocessing is recommended to
refresh it in case of change.
"""
MEDIA_NAME = "file"
EXPIRES = 90
STORE_SCHEMES = {
'': FSFilesStore,
'file': FSFilesStore,
's3': S3FilesStore,
'gs': GCSFilesStore,
'ftp': FTPFilesStore
}
DEFAULT_FILES_URLS_FIELD = 'file_urls'
DEFAULT_FILES_RESULT_FIELD = 'files'
def __init__(self, store_uri, download_func=None, settings=None):
if not store_uri:
raise NotConfigured
if isinstance(settings, dict) or settings is None:
settings = Settings(settings)
cls_name = "FilesPipeline"
self.store = self._get_store(store_uri)
resolve = functools.partial(self._key_for_pipe,
base_class_name=cls_name,
settings=settings)
self.expires = settings.getint(
resolve('FILES_EXPIRES'), self.EXPIRES
)
if not hasattr(self, "FILES_URLS_FIELD"):
self.FILES_URLS_FIELD = self.DEFAULT_FILES_URLS_FIELD
if not hasattr(self, "FILES_RESULT_FIELD"):
self.FILES_RESULT_FIELD = self.DEFAULT_FILES_RESULT_FIELD
self.files_urls_field = settings.get(
resolve('FILES_URLS_FIELD'), self.FILES_URLS_FIELD
)
self.files_result_field = settings.get(
resolve('FILES_RESULT_FIELD'), self.FILES_RESULT_FIELD
)
super(FilesPipeline, self).__init__(download_func=download_func, settings=settings)
@classmethod
def from_settings(cls, settings):
s3store = cls.STORE_SCHEMES['s3']
s3store.AWS_ACCESS_KEY_ID = settings['AWS_ACCESS_KEY_ID']
s3store.AWS_SECRET_ACCESS_KEY = settings['AWS_SECRET_ACCESS_KEY']
s3store.AWS_ENDPOINT_URL = settings['AWS_ENDPOINT_URL']
s3store.AWS_REGION_NAME = settings['AWS_REGION_NAME']
s3store.AWS_USE_SSL = settings['AWS_USE_SSL']
s3store.AWS_VERIFY = settings['AWS_VERIFY']
s3store.POLICY = settings['FILES_STORE_S3_ACL']
gcs_store = cls.STORE_SCHEMES['gs']
gcs_store.GCS_PROJECT_ID = settings['GCS_PROJECT_ID']
gcs_store.POLICY = settings['FILES_STORE_GCS_ACL'] or None
ftp_store = cls.STORE_SCHEMES['ftp']
ftp_store.FTP_USERNAME = settings['FTP_USER']
ftp_store.FTP_PASSWORD = settings['FTP_PASSWORD']
ftp_store.USE_ACTIVE_MODE = settings.getbool('FEED_STORAGE_FTP_ACTIVE')
store_uri = settings['FILES_STORE']
return cls(store_uri, settings=settings)
def _get_store(self, uri):
if os.path.isabs(uri): # to support win32 paths like: C:\\some\dir
scheme = 'file'
else:
scheme = urlparse(uri).scheme
store_cls = self.STORE_SCHEMES[scheme]
return store_cls(uri)
def media_to_download(self, request, info):
def _onsuccess(result):
if not result:
return # returning None force download
last_modified = result.get('last_modified', None)
if not last_modified:
return # returning None force download
age_seconds = time.time() - last_modified
age_days = age_seconds / 60 / 60 / 24
if age_days > self.expires:
return # returning None force download
referer = referer_str(request)
logger.debug(
'File (uptodate): Downloaded %(medianame)s from %(request)s '
'referred in <%(referer)s>',
{'medianame': self.MEDIA_NAME, 'request': request,
'referer': referer},
extra={'spider': info.spider}
)
self.inc_stats(info.spider, 'uptodate')
checksum = result.get('checksum', None)
return {'url': request.url, 'path': path, 'checksum': checksum}
path = self.file_path(request, info=info)
dfd = defer.maybeDeferred(self.store.stat_file, path, info)
dfd.addCallbacks(_onsuccess, lambda _: None)
dfd.addErrback(
lambda f:
logger.error(self.__class__.__name__ + '.store.stat_file',
exc_info=failure_to_exc_info(f),
extra={'spider': info.spider})
)
return dfd
def media_failed(self, failure, request, info):
if not isinstance(failure.value, IgnoreRequest):
referer = referer_str(request)
logger.warning(
'File (unknown-error): Error downloading %(medianame)s from '
'%(request)s referred in <%(referer)s>: %(exception)s',
{'medianame': self.MEDIA_NAME, 'request': request,
'referer': referer, 'exception': failure.value},
extra={'spider': info.spider}
)
raise FileException
def media_downloaded(self, response, request, info):
referer = referer_str(request)
if response.status != 200:
logger.warning(
'File (code: %(status)s): Error downloading file from '
'%(request)s referred in <%(referer)s>',
{'status': response.status,
'request': request, 'referer': referer},
extra={'spider': info.spider}
)
raise FileException('download-error')
if not response.body:
logger.warning(
'File (empty-content): Empty file from %(request)s referred '
'in <%(referer)s>: no-content',
{'request': request, 'referer': referer},
extra={'spider': info.spider}
)
raise FileException('empty-content')
status = 'cached' if 'cached' in response.flags else 'downloaded'
logger.debug(
'File (%(status)s): Downloaded file from %(request)s referred in '
'<%(referer)s>',
{'status': status, 'request': request, 'referer': referer},
extra={'spider': info.spider}
)
self.inc_stats(info.spider, status)
try:
path = self.file_path(request, response=response, info=info)
checksum = self.file_downloaded(response, request, info)
except FileException as exc:
logger.warning(
'File (error): Error processing file from %(request)s '
'referred in <%(referer)s>: %(errormsg)s',
{'request': request, 'referer': referer, 'errormsg': str(exc)},
extra={'spider': info.spider}, exc_info=True
)
raise
except Exception as exc:
logger.error(
'File (unknown-error): Error processing file from %(request)s '
'referred in <%(referer)s>',
{'request': request, 'referer': referer},
exc_info=True, extra={'spider': info.spider}
)
raise FileException(str(exc))
return {'url': request.url, 'path': path, 'checksum': checksum}
def inc_stats(self, spider, status):
spider.crawler.stats.inc_value('file_count', spider=spider)
spider.crawler.stats.inc_value('file_status_count/%s' % status, spider=spider)
# Overridable Interface
def get_media_requests(self, item, info):
return [Request(x) for x in item.get(self.files_urls_field, [])]
def file_downloaded(self, response, request, info):
path = self.file_path(request, response=response, info=info)
buf = BytesIO(response.body)
checksum = md5sum(buf)
buf.seek(0)
self.store.persist_file(path, buf, info)
return checksum
def item_completed(self, results, item, info):
if isinstance(item, dict) or self.files_result_field in item.fields:
item[self.files_result_field] = [x for ok, x in results if ok]
return item
def file_path(self, request, response=None, info=None):
media_guid = hashlib.sha1(to_bytes(request.url)).hexdigest()
media_ext = os.path.splitext(request.url)[1]
# Handles empty and wild extensions by trying to guess the
# mime type then extension or default to empty string otherwise
if media_ext not in mimetypes.types_map:
media_ext = ''
media_type = mimetypes.guess_type(request.url)[0]
if media_type:
media_ext = mimetypes.guess_extension(media_type)
return 'full/%s%s' % (media_guid, media_ext)