201 lines
7.1 KiB
Python
201 lines
7.1 KiB
Python
#!/usr/bin/env python3.5
|
|
|
|
import os
|
|
import argparse
|
|
import asyncio
|
|
import logging
|
|
from fnmatch import fnmatch
|
|
from time import sleep
|
|
from bs4 import BeautifulSoup
|
|
from urllib.parse import urljoin, unquote, urlsplit, urlunsplit
|
|
from collections import namedtuple
|
|
from requests import Session
|
|
from concurrent.futures import ThreadPoolExecutor
|
|
from contextlib import closing
|
|
|
|
|
|
ScrapeConfig = namedtuple("ScrapeConfig", "output loop executor base_url visited futures semaphore delay exclude")
|
|
"""
|
|
output: base dest dir to put downloaded files
|
|
loop: asyncio loop object
|
|
executor: large file download threadpool executor
|
|
base_url: remote open dir base url to scan
|
|
visited: list of urls already visiting/visited
|
|
"""
|
|
|
|
|
|
class AlreadyDownloadedException(Exception):
|
|
pass
|
|
|
|
|
|
http = Session()
|
|
|
|
|
|
def clean_url(url):
|
|
"""
|
|
Run a url through urlsplit and urljoin, ensuring uniform url format
|
|
"""
|
|
return urlunsplit(urlsplit(url))
|
|
|
|
|
|
def stream_url(url, **kwargs):
|
|
"""
|
|
Return a request's Response object for the given URL
|
|
"""
|
|
return http.get(url, stream=True, **kwargs)
|
|
|
|
|
|
def get_links(content):
|
|
"""
|
|
Parse and return hrefs for all links on a given page
|
|
:param content: html body to scan
|
|
"""
|
|
doc = BeautifulSoup(content, "html.parser")
|
|
for link in doc.find_all("a"):
|
|
href = link.attrs.get('href', None)
|
|
if href:
|
|
yield href
|
|
|
|
|
|
def stream_to_file(response, url, options):
|
|
url_suffix = unquote(url[len(options.base_url):])
|
|
local_path = os.path.normpath(os.path.join(options.output, url_suffix))
|
|
|
|
if not local_path.startswith(options.output):
|
|
raise Exception("Aborted: directory traversal detected!")
|
|
|
|
try:
|
|
for pattern in options.exclude:
|
|
if fnmatch(url_suffix, pattern):
|
|
logging.info("Excluded: '%s' on pattern '%s'", url_suffix, pattern)
|
|
raise AlreadyDownloadedException("Excluded")
|
|
|
|
os.makedirs(os.path.dirname(local_path), exist_ok=True)
|
|
|
|
if os.path.exists(local_path):
|
|
response.close()
|
|
# Local file exists, restart request with range
|
|
fsize = os.path.getsize(local_path)
|
|
remote_size = int(response.headers.get("Content-length"))
|
|
|
|
if fsize == remote_size:
|
|
raise AlreadyDownloadedException("Already downloaded")
|
|
|
|
logging.info("{} already exists, restarting request with range {}-{}".format(local_path, fsize,
|
|
remote_size))
|
|
if options.delay:
|
|
sleep(options.delay)
|
|
|
|
logging.warning("Downloading {} to {}".format(url, local_path))
|
|
response = stream_url(url, headers={"Range": "bytes={}-{}".format(fsize, remote_size)})
|
|
response.raise_for_status() # TODO: clobber file and restart w/ no range header if range not satisfiable
|
|
|
|
with open(local_path, "wb") as f:
|
|
for chunk in response.iter_content(chunk_size=256 * 1024):
|
|
f.write(chunk)
|
|
finally:
|
|
options.semaphore.release()
|
|
try:
|
|
response.close()
|
|
except:
|
|
pass
|
|
return (url, local_path)
|
|
|
|
|
|
async def scrape_url(url, options, skip=False):
|
|
"""
|
|
- Request the URL
|
|
- If HTML, parse and recurse
|
|
- If other, download
|
|
"""
|
|
options.visited.append(url)
|
|
|
|
g = await options.loop.run_in_executor(None, stream_url, url)
|
|
|
|
if g.status_code != 200:
|
|
logging.error("Fetch failed, code was %s", g.status_code)
|
|
return
|
|
|
|
content_type = g.headers.get("Content-Type", "")
|
|
if "text/html" in content_type:
|
|
# HTML page, parse it
|
|
for link in get_links(g.text):
|
|
link_dest = clean_url(urljoin(url, link))
|
|
if not link_dest.startswith(options.base_url):
|
|
# Link leads outside the base_url, skip it
|
|
continue
|
|
if link_dest not in options.visited:
|
|
# link is valid and not seen before, visit it
|
|
logging.info("Visiting %s", url)
|
|
await scrape_url(link_dest, options)
|
|
g.close()
|
|
else:
|
|
# Actual file, download it
|
|
# await download_file(g, url, options)
|
|
await options.semaphore.acquire()
|
|
options.futures.append((options.executor.submit(stream_to_file, g, url, options), url, ))
|
|
# Purge completed futures
|
|
for item in options.futures[:]:
|
|
future, url = item
|
|
if future.done():
|
|
options.futures.remove(item)
|
|
exc = future.exception()
|
|
if exc:
|
|
if type(exc) is AlreadyDownloadedException:
|
|
logging.info("ALREADY COMPLETE: url: %s", url)
|
|
else:
|
|
logging.error("FAILED: %s: %s", url, exc)
|
|
else:
|
|
logging.warning("COMPLETED downloading url %s to %s", *future.result())
|
|
|
|
|
|
def main():
|
|
parser = argparse.ArgumentParser(description="Open directory scraper")
|
|
parser.add_argument('-u', '--url', help="url to scrape")
|
|
parser.add_argument('-o', '--output-dir', help="destination for downloaded files")
|
|
parser.add_argument('-p', '--parallel', type=int, default=5, help="number of downloads to execute in parallel")
|
|
parser.add_argument('-c', '--clobber', action="store_true", help="clobber existing files instead of resuming")
|
|
parser.add_argument('-d', '--delay', type=int, default=0, help="delay between requests")
|
|
parser.add_argument('-e', '--exclude', default=[], nargs="+", help="exclude patterns")
|
|
parser.add_argument('-f', '--exclude-from', help="exclude patterns from file")
|
|
parser.add_argument('-v', '--verbose', action="store_true", help="enable info logging")
|
|
args = parser.parse_args()
|
|
|
|
logging.basicConfig(level=logging.DEBUG if args.verbose else logging.WARNING,
|
|
format="%(asctime)-15s %(levelname)-8s %(filename)s:%(lineno)d %(message)s")
|
|
|
|
logging.debug("cli args: %s", args)
|
|
|
|
excludes = list(args.exclude)
|
|
if args.exclude_from:
|
|
with open(args.exclude_from) as f:
|
|
excludes += [l.strip() for l in f.readlines() if l.strip()]
|
|
|
|
with ThreadPoolExecutor(max_workers=args.parallel) as executor:
|
|
with closing(asyncio.get_event_loop()) as loop:
|
|
loop.set_debug(True)
|
|
loop.set_default_executor(executor)
|
|
|
|
base_url = clean_url(args.url)
|
|
|
|
config = ScrapeConfig(os.path.normpath(args.output_dir),
|
|
loop,
|
|
executor,
|
|
base_url,
|
|
[], # visited urls
|
|
[], # futures
|
|
asyncio.Semaphore(value=args.parallel),
|
|
args.delay,
|
|
excludes)
|
|
|
|
downloader = asyncio.ensure_future(scrape_url(base_url, config), loop=loop)
|
|
try:
|
|
loop.set_debug(True)
|
|
loop.run_until_complete(downloader)
|
|
finally:
|
|
logging.debug("Escaped main loop")
|
|
|
|
|
|
if __name__ == '__main__':
|
|
main()
|