Source code for sphinx.builders.linkcheck

"""
    sphinx.builders.linkcheck
    ~~~~~~~~~~~~~~~~~~~~~~~~~

    The CheckExternalLinksBuilder class.

    :copyright: Copyright 2007-2021 by the Sphinx team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

import json
import re
import socket
import time
from datetime import datetime, timezone
from email.utils import parsedate_to_datetime
from html.parser import HTMLParser
from os import path
from queue import PriorityQueue, Queue
from threading import Thread
from typing import Any, Dict, Generator, List, NamedTuple, Optional, Tuple, Union, cast
from urllib.parse import unquote, urlparse, urlunparse

from docutils import nodes
from requests import Response
from requests.exceptions import ConnectionError, HTTPError, TooManyRedirects

from sphinx.application import Sphinx
from sphinx.builders.dummy import DummyBuilder
from sphinx.config import Config
from sphinx.environment import BuildEnvironment
from sphinx.locale import __
from sphinx.transforms.post_transforms import SphinxPostTransform
from sphinx.util import encode_uri, logging, requests
from sphinx.util.console import darkgray, darkgreen, purple, red, turquoise  # type: ignore
from sphinx.util.nodes import get_node_line

logger = logging.getLogger(__name__)

uri_re = re.compile('([a-z]+:)?//')  # matches to foo:// and // (a protocol relative URL)

Hyperlink = NamedTuple('Hyperlink', (('uri', str),
                                     ('docname', str),
                                     ('lineno', Optional[int])))
CheckRequest = NamedTuple('CheckRequest', (('next_check', float),
                                           ('hyperlink', Optional[Hyperlink])))
CheckResult = NamedTuple('CheckResult', (('uri', str),
                                         ('docname', str),
                                         ('lineno', int),
                                         ('status', str),
                                         ('message', str),
                                         ('code', int)))
RateLimit = NamedTuple('RateLimit', (('delay', float), ('next_check', float)))

# Tuple is old styled CheckRequest
CheckRequestType = Union[CheckRequest, Tuple[float, str, str, int]]

DEFAULT_REQUEST_HEADERS = {
    'Accept': 'text/html,application/xhtml+xml;q=0.9,*/*;q=0.8',
}
CHECK_IMMEDIATELY = 0
QUEUE_POLL_SECS = 1
DEFAULT_DELAY = 60.0


class AnchorCheckParser(HTMLParser):
    """Specialized HTML parser that looks for a specific anchor."""

    def __init__(self, search_anchor: str) -> None:
        super().__init__()

        self.search_anchor = search_anchor
        self.found = False

    def handle_starttag(self, tag: Any, attrs: Any) -> None:
        for key, value in attrs:
            if key in ('id', 'name') and value == self.search_anchor:
                self.found = True
                break


def check_anchor(response: requests.requests.Response, anchor: str) -> bool:
    """Reads HTML data from a response object `response` searching for `anchor`.
    Returns True if anchor was found, False otherwise.
    """
    parser = AnchorCheckParser(anchor)
    # Read file in chunks. If we find a matching anchor, we break
    # the loop early in hopes not to have to download the whole thing.
    for chunk in response.iter_content(chunk_size=4096, decode_unicode=True):
        if isinstance(chunk, bytes):    # requests failed to decode
            chunk = chunk.decode()      # manually try to decode it

        parser.feed(chunk)
        if parser.found:
            break
    parser.close()
    return parser.found


[docs]class CheckExternalLinksBuilder(DummyBuilder): """ Checks for broken external links. """ name = 'linkcheck' epilog = __('Look for any errors in the above output or in ' '%(outdir)s/output.txt') def init(self) -> None: self.broken_hyperlinks = 0 self.hyperlinks: Dict[str, Hyperlink] = {} # set a timeout for non-responding servers socket.setdefaulttimeout(5.0) def process_result(self, result: CheckResult) -> None: filename = self.env.doc2path(result.docname, None) linkstat = dict(filename=filename, lineno=result.lineno, status=result.status, code=result.code, uri=result.uri, info=result.message) self.write_linkstat(linkstat) if result.status == 'unchecked': return if result.status == 'working' and result.message == 'old': return if result.lineno: logger.info('(%16s: line %4d) ', result.docname, result.lineno, nonl=True) if result.status == 'ignored': if result.message: logger.info(darkgray('-ignored- ') + result.uri + ': ' + result.message) else: logger.info(darkgray('-ignored- ') + result.uri) elif result.status == 'local': logger.info(darkgray('-local- ') + result.uri) self.write_entry('local', result.docname, filename, result.lineno, result.uri) elif result.status == 'working': logger.info(darkgreen('ok ') + result.uri + result.message) elif result.status == 'broken': if self.app.quiet or self.app.warningiserror: logger.warning(__('broken link: %s (%s)'), result.uri, result.message, location=(filename, result.lineno)) else: logger.info(red('broken ') + result.uri + red(' - ' + result.message)) self.write_entry('broken', result.docname, filename, result.lineno, result.uri + ': ' + result.message) self.broken_hyperlinks += 1 elif result.status == 'redirected': try: text, color = { 301: ('permanently', purple), 302: ('with Found', purple), 303: ('with See Other', purple), 307: ('temporarily', turquoise), 308: ('permanently', purple), }[result.code] except KeyError: text, color = ('with unknown code', purple) linkstat['text'] = text if self.config.linkcheck_allowed_redirects: logger.warning('redirect ' + result.uri + ' - ' + text + ' to ' + result.message, location=(filename, result.lineno)) else: logger.info(color('redirect ') + result.uri + color(' - ' + text + ' to ' + result.message)) self.write_entry('redirected ' + text, result.docname, filename, result.lineno, result.uri + ' to ' + result.message) else: raise ValueError("Unknown status %s." % result.status) def write_entry(self, what: str, docname: str, filename: str, line: int, uri: str) -> None: self.txt_outfile.write("%s:%s: [%s] %s\n" % (filename, line, what, uri)) def write_linkstat(self, data: dict) -> None: self.json_outfile.write(json.dumps(data)) self.json_outfile.write('\n') def finish(self) -> None: checker = HyperlinkAvailabilityChecker(self.env, self.config) logger.info('') with open(path.join(self.outdir, 'output.txt'), 'w') as self.txt_outfile,\ open(path.join(self.outdir, 'output.json'), 'w') as self.json_outfile: for result in checker.check(self.hyperlinks): self.process_result(result) if self.broken_hyperlinks: self.app.statuscode = 1
class HyperlinkAvailabilityChecker: def __init__(self, env: BuildEnvironment, config: Config) -> None: self.config = config self.env = env self.rate_limits: Dict[str, RateLimit] = {} self.rqueue: Queue = Queue() self.workers: List[Thread] = [] self.wqueue: PriorityQueue = PriorityQueue() self.to_ignore = [re.compile(x) for x in self.config.linkcheck_ignore] def invoke_threads(self) -> None: for i in range(self.config.linkcheck_workers): thread = HyperlinkAvailabilityCheckWorker(self.env, self.config, self.rqueue, self.wqueue, self.rate_limits) thread.start() self.workers.append(thread) def shutdown_threads(self) -> None: self.wqueue.join() for worker in self.workers: self.wqueue.put(CheckRequest(CHECK_IMMEDIATELY, None), False) def check(self, hyperlinks: Dict[str, Hyperlink]) -> Generator[CheckResult, None, None]: self.invoke_threads() total_links = 0 for hyperlink in hyperlinks.values(): if self.is_ignored_uri(hyperlink.uri): yield CheckResult(hyperlink.uri, hyperlink.docname, hyperlink.lineno, 'ignored', '', 0) else: self.wqueue.put(CheckRequest(CHECK_IMMEDIATELY, hyperlink), False) total_links += 1 done = 0 while done < total_links: yield self.rqueue.get() done += 1 self.shutdown_threads() def is_ignored_uri(self, uri: str) -> bool: return any(pat.match(uri) for pat in self.to_ignore) class HyperlinkAvailabilityCheckWorker(Thread): """A worker class for checking the availability of hyperlinks.""" def __init__(self, env: BuildEnvironment, config: Config, rqueue: Queue, wqueue: Queue, rate_limits: Dict[str, RateLimit]) -> None: self.config = config self.env = env self.rate_limits = rate_limits self.rqueue = rqueue self.wqueue = wqueue self.anchors_ignore = [re.compile(x) for x in self.config.linkcheck_anchors_ignore] self.auth = [(re.compile(pattern), auth_info) for pattern, auth_info in self.config.linkcheck_auth] super().__init__(daemon=True) def run(self) -> None: kwargs = {} if self.config.linkcheck_timeout: kwargs['timeout'] = self.config.linkcheck_timeout def get_request_headers() -> Dict: url = urlparse(uri) candidates = ["%s://%s" % (url.scheme, url.netloc), "%s://%s/" % (url.scheme, url.netloc), uri, "*"] for u in candidates: if u in self.config.linkcheck_request_headers: headers = dict(DEFAULT_REQUEST_HEADERS) headers.update(self.config.linkcheck_request_headers[u]) return headers return {} def check_uri() -> Tuple[str, str, int]: # split off anchor if '#' in uri: req_url, anchor = uri.split('#', 1) for rex in self.anchors_ignore: if rex.match(anchor): anchor = None break else: req_url = uri anchor = None # handle non-ASCII URIs try: req_url.encode('ascii') except UnicodeError: req_url = encode_uri(req_url) # Get auth info, if any for pattern, auth_info in self.auth: if pattern.match(uri): break else: auth_info = None # update request headers for the URL kwargs['headers'] = get_request_headers() try: if anchor and self.config.linkcheck_anchors: # Read the whole document and see if #anchor exists response = requests.get(req_url, stream=True, config=self.config, auth=auth_info, **kwargs) response.raise_for_status() found = check_anchor(response, unquote(anchor)) if not found: raise Exception(__("Anchor '%s' not found") % anchor) else: try: # try a HEAD request first, which should be easier on # the server and the network response = requests.head(req_url, allow_redirects=True, config=self.config, auth=auth_info, **kwargs) response.raise_for_status() # Servers drop the connection on HEAD requests, causing # ConnectionError. except (ConnectionError, HTTPError, TooManyRedirects) as err: if isinstance(err, HTTPError) and err.response.status_code == 429: raise # retry with GET request if that fails, some servers # don't like HEAD requests. response = requests.get(req_url, stream=True, config=self.config, auth=auth_info, **kwargs) response.raise_for_status() except HTTPError as err: if err.response.status_code == 401: # We'll take "Unauthorized" as working. return 'working', ' - unauthorized', 0 elif err.response.status_code == 429: next_check = self.limit_rate(err.response) if next_check is not None: self.wqueue.put(CheckRequest(next_check, hyperlink), False) return 'rate-limited', '', 0 return 'broken', str(err), 0 elif err.response.status_code == 503: # We'll take "Service Unavailable" as ignored. return 'ignored', str(err), 0 else: return 'broken', str(err), 0 except Exception as err: return 'broken', str(err), 0 else: netloc = urlparse(req_url).netloc try: del self.rate_limits[netloc] except KeyError: pass if response.url.rstrip('/') == req_url.rstrip('/'): return 'working', '', 0 else: new_url = response.url if anchor: new_url += '#' + anchor if allowed_redirect(req_url, new_url): return 'working', '', 0 elif response.history: # history contains any redirects, get last code = response.history[-1].status_code return 'redirected', new_url, code else: return 'redirected', new_url, 0 def allowed_redirect(url: str, new_url: str) -> bool: for from_url, to_url in self.config.linkcheck_allowed_redirects.items(): if from_url.match(url) and to_url.match(new_url): return True return False def check(docname: str) -> Tuple[str, str, int]: # check for various conditions without bothering the network if len(uri) == 0 or uri.startswith(('#', 'mailto:', 'tel:')): return 'unchecked', '', 0 elif not uri.startswith(('http:', 'https:')): if uri_re.match(uri): # non supported URI schemes (ex. ftp) return 'unchecked', '', 0 else: srcdir = path.dirname(self.env.doc2path(docname)) if path.exists(path.join(srcdir, uri)): return 'working', '', 0 else: return 'broken', '', 0 # need to actually check the URI for _ in range(self.config.linkcheck_retries): status, info, code = check_uri() if status != "broken": break return (status, info, code) while True: check_request = self.wqueue.get() try: next_check, hyperlink = check_request if hyperlink is None: break uri, docname, lineno = hyperlink except ValueError: # old styled check_request (will be deprecated in Sphinx-5.0) next_check, uri, docname, lineno = check_request if uri is None: break netloc = urlparse(uri).netloc try: # Refresh rate limit. # When there are many links in the queue, workers are all stuck waiting # for responses, but the builder keeps queuing. Links in the queue may # have been queued before rate limits were discovered. next_check = self.rate_limits[netloc].next_check except KeyError: pass if next_check > time.time(): # Sleep before putting message back in the queue to avoid # waking up other threads. time.sleep(QUEUE_POLL_SECS) self.wqueue.put(CheckRequest(next_check, hyperlink), False) self.wqueue.task_done() continue status, info, code = check(docname) if status == 'rate-limited': logger.info(darkgray('-rate limited- ') + uri + darkgray(' | sleeping...')) else: self.rqueue.put(CheckResult(uri, docname, lineno, status, info, code)) self.wqueue.task_done() def limit_rate(self, response: Response) -> Optional[float]: next_check = None retry_after = response.headers.get("Retry-After") if retry_after: try: # Integer: time to wait before next attempt. delay = float(retry_after) except ValueError: try: # An HTTP-date: time of next attempt. until = parsedate_to_datetime(retry_after) except (TypeError, ValueError): # TypeError: Invalid date format. # ValueError: Invalid date, e.g. Oct 52th. pass else: next_check = datetime.timestamp(until) delay = (until - datetime.now(timezone.utc)).total_seconds() else: next_check = time.time() + delay netloc = urlparse(response.url).netloc if next_check is None: max_delay = self.config.linkcheck_rate_limit_timeout try: rate_limit = self.rate_limits[netloc] except KeyError: delay = DEFAULT_DELAY else: last_wait_time = rate_limit.delay delay = 2.0 * last_wait_time if delay > max_delay and last_wait_time < max_delay: delay = max_delay if delay > max_delay: return None next_check = time.time() + delay self.rate_limits[netloc] = RateLimit(delay, next_check) return next_check class HyperlinkCollector(SphinxPostTransform): builders = ('linkcheck',) default_priority = 800 def run(self, **kwargs: Any) -> None: builder = cast(CheckExternalLinksBuilder, self.app.builder) hyperlinks = builder.hyperlinks # reference nodes for refnode in self.document.traverse(nodes.reference): if 'refuri' not in refnode: continue uri = refnode['refuri'] newuri = self.app.emit_firstresult('linkcheck-process-uri', uri) if newuri: uri = newuri lineno = get_node_line(refnode) uri_info = Hyperlink(uri, self.env.docname, lineno) if uri not in hyperlinks: hyperlinks[uri] = uri_info # image nodes for imgnode in self.document.traverse(nodes.image): uri = imgnode['candidates'].get('?') if uri and '://' in uri: newuri = self.app.emit_firstresult('linkcheck-process-uri', uri) if newuri: uri = newuri lineno = get_node_line(imgnode) uri_info = Hyperlink(uri, self.env.docname, lineno) if uri not in hyperlinks: hyperlinks[uri] = uri_info def rewrite_github_anchor(app: Sphinx, uri: str) -> Optional[str]: """Rewrite anchor name of the hyperlink to github.com The hyperlink anchors in github.com are dynamically generated. This rewrites them before checking and makes them comparable. """ parsed = urlparse(uri) if parsed.hostname == "github.com" and parsed.fragment: prefixed = parsed.fragment.startswith('user-content-') if not prefixed: fragment = f'user-content-{parsed.fragment}' return urlunparse(parsed._replace(fragment=fragment)) return None def compile_linkcheck_allowed_redirects(app: Sphinx, config: Config) -> None: """Compile patterns in linkcheck_allowed_redirects to the regexp objects.""" for url, pattern in list(app.config.linkcheck_allowed_redirects.items()): try: app.config.linkcheck_allowed_redirects[re.compile(url)] = re.compile(pattern) except re.error as exc: logger.warning(__('Failed to compile regex in linkcheck_allowed_redirects: %r %s'), exc.pattern, exc.msg) finally: # Remove the original regexp-string app.config.linkcheck_allowed_redirects.pop(url) def setup(app: Sphinx) -> Dict[str, Any]: app.add_builder(CheckExternalLinksBuilder) app.add_post_transform(HyperlinkCollector) app.add_config_value('linkcheck_ignore', [], None) app.add_config_value('linkcheck_allowed_redirects', {}, None) app.add_config_value('linkcheck_auth', [], None) app.add_config_value('linkcheck_request_headers', {}, None) app.add_config_value('linkcheck_retries', 1, None) app.add_config_value('linkcheck_timeout', None, None, [int]) app.add_config_value('linkcheck_workers', 5, None) app.add_config_value('linkcheck_anchors', True, None) # Anchors starting with ! are ignored since they are # commonly used for dynamic pages app.add_config_value('linkcheck_anchors_ignore', ["^!"], None) app.add_config_value('linkcheck_rate_limit_timeout', 300.0, None) app.add_event('linkcheck-process-uri') app.connect('config-inited', compile_linkcheck_allowed_redirects, priority=800) # FIXME: Disable URL rewrite handler for github.com temporarily. # ref: https://github.com/sphinx-doc/sphinx/issues/9435 # app.connect('linkcheck-process-uri', rewrite_github_anchor) return { 'version': 'builtin', 'parallel_read_safe': True, 'parallel_write_safe': True, }