def get_webmention_target(url, resolve=True, replace_test_domains=True):
"""Resolves a URL and decides whether we should try to send it a webmention.
Note that this ignores failed HTTP requests, ie the boolean in the returned
tuple will be true! TODO: check callers and reconsider this.
Args:
url: string
resolve: whether to follow redirects
replace_test_domains: whether to replace test user domains with localhost
Returns: (string url, string pretty domain, boolean) tuple. The boolean is
True if we should send a webmention, False otherwise, e.g. if it's a bad
URL, not text/html, or in the blacklist.
"""
url = util.clean_url(url)
try:
domain = domain_from_link(url).lower()
except BaseException:
logging.info('Dropping bad URL %s.', url)
return url, None, False
send = True
if resolve:
# this follows *all* redirects, until the end
resolved = follow_redirects(url, cache=memcache)
send = resolved.headers.get('content-type', '').startswith('text/html')
url, domain, _ = get_webmention_target(
resolved.url, resolve=False, replace_test_domains=replace_test_domains)
send = send and domain and not in_webmention_blacklist(domain)
if replace_test_domains:
url = replace_test_domains_with_localhost(url)
return url, domain, send
def get_webmention_target(url, resolve=True, replace_test_domains=True):
"""Resolves a URL and decides whether we should try to send it a webmention.
Note that this ignores failed HTTP requests, ie the boolean in the returned
tuple will be true! TODO: check callers and reconsider this.
Args:
url: string
resolve: whether to follow redirects
replace_test_domains: whether to replace test user domains with localhost
Returns:
(string url, string pretty domain, boolean) tuple. The boolean is
True if we should send a webmention, False otherwise, e.g. if it's a bad
URL, not text/html, or in the blacklist.
"""
url = util.clean_url(url)
try:
domain = domain_from_link(url).lower()
except BaseException:
logging.info('Dropping bad URL %s.', url)
return url, None, False
send = True
if resolve:
# this follows *all* redirects, until the end
resolved = follow_redirects(url, cache=memcache)
send = resolved.headers.get('content-type', '').startswith('text/html')
url, domain, _ = get_webmention_target(
resolved.url, resolve=False, replace_test_domains=replace_test_domains)
send = send and domain and not in_webmention_blacklist(domain)
if replace_test_domains:
url = replace_test_domains_with_localhost(url)
return url, domain, send
def get_webmention_target(url, resolve=True, replace_test_domains=True):
"""Resolves a URL and decides whether we should try to send it a webmention.
Note that this ignores failed HTTP requests, ie the boolean in the returned
tuple will be True! TODO: check callers and reconsider this.
Args:
url: string
resolve: whether to follow redirects
replace_test_domains: whether to replace test user domains with localhost
Returns:
(string url, string pretty domain, boolean) tuple. The boolean is
True if we should send a webmention, False otherwise, e.g. if it's a bad
URL, not text/html, or in the blocklist.
"""
url = util.clean_url(url)
try:
domain = domain_from_link(url).lower()
except BaseException:
logging.info('Dropping bad URL %s.', url)
return url, None, False
if domain in ('puzzleadventura.com', 'sweetgamesbox.com'):
return url, domain, False
send = True
if resolve:
# this follows *all* redirects, until the end
resolved = follow_redirects(url)
html = resolved.headers.get('content-type', '').startswith('text/html')
send = html and resolved.status_code != util.HTTP_RESPONSE_TOO_BIG_STATUS_CODE
url, domain, _ = get_webmention_target(
resolved.url,
resolve=False,
replace_test_domains=replace_test_domains)
scheme = urllib.parse.urlparse(url).scheme # require http or https
send = (send and domain and scheme in ('http', 'https')
and not in_webmention_blocklist(domain))
if replace_test_domains:
url = replace_test_domains_with_localhost(url)
return url, domain, send
def original_post_discovery(activity,
domains=None,
cache=None,
include_redirect_sources=True,
**kwargs):
"""Discovers original post links.
This is a variation on http://indiewebcamp.com/original-post-discovery . It
differs in that it finds multiple candidate links instead of one, and it
doesn't bother looking for MF2 (etc) markup because the silos don't let you
input it. More background:
https://github.com/snarfed/bridgy/issues/51#issuecomment-136018857
Original post candidates come from the upstreamDuplicates, attachments, and
tags fields, as well as links and permashortlinks/permashortcitations in the
text content.
Args:
activity: activity dict
domains: optional sequence of domains. If provided, only links to these
domains will be considered original and stored in upstreamDuplicates.
(Permashortcitations are exempt.)
cache: optional, a cache object for storing resolved URL redirects. Passed
to follow_redirects().
include_redirect_sources: boolean, whether to include URLs that redirect
as well as their final destination URLs
kwargs: passed to requests.head() when following redirects
Returns:
([string original post URLs], [string mention URLs]) tuple
"""
obj = activity.get('object') or activity
content = obj.get('content', '').strip()
# find all candidate URLs
tags = [
t.get('url')
for t in obj.get('attachments', []) + obj.get('tags', [])
if t.get('objectType') in ('article', 'mention', None)
]
candidates = tags + util.extract_links(content) + obj.get(
'upstreamDuplicates', [])
# Permashortcitations (http://indiewebcamp.com/permashortcitation) are short
# references to canonical copies of a given (usually syndicated) post, of
# the form (DOMAIN PATH). We consider them an explicit original post link.
candidates += [
match.expand(r'http://\1/\2')
for match in Source._PERMASHORTCITATION_RE.finditer(content)
]
candidates = set(
filter(
None,
(
util.clean_url(url) for url in candidates
# heuristic: ellipsized URLs are probably incomplete, so omit them.
if url and not url.endswith('...')
and not url.endswith(u'…'))))
# check for redirect and add their final urls
redirects = {} # maps final URL to original URL for redirects
for url in list(candidates):
resolved = util.follow_redirects(url, cache=cache, **kwargs)
if (resolved.url != url and resolved.headers.get(
'content-type', '').startswith('text/html')):
redirects[resolved.url] = url
candidates.add(resolved.url)
# use domains to determine which URLs are original post links vs mentions
originals = set()
mentions = set()
for url in util.dedupe_urls(candidates):
if url in redirects.values():
# this is a redirected original URL. postpone and handle it when we hit
# its final URL so that we know the final domain.
continue
domain = util.domain_from_link(url)
which = (originals if not domains or util.domain_or_parent_in(
domain, domains) else mentions)
which.add(url)
redirected_from = redirects.get(url)
if redirected_from and include_redirect_sources:
which.add(redirected_from)
logging.info(
'Original post discovery found original posts %s, mentions %s',
originals, mentions)
return originals, mentions
def original_post_discovery(activity, domains=None, cache=None, include_redirect_sources=True, **kwargs):
"""Discovers original post links.
This is a variation on http://indiewebcamp.com/original-post-discovery . It
differs in that it finds multiple candidate links instead of one, and it
doesn't bother looking for MF2 (etc) markup because the silos don't let you
input it. More background:
https://github.com/snarfed/bridgy/issues/51#issuecomment-136018857
Original post candidates come from the upstreamDuplicates, attachments, and
tags fields, as well as links and permashortlinks/permashortcitations in the
text content.
Args:
activity: activity dict
domains: optional sequence of domains. If provided, only links to these
domains will be considered original and stored in upstreamDuplicates.
(Permashortcitations are exempt.)
cache: optional, a cache object for storing resolved URL redirects. Passed
to follow_redirects().
include_redirect_sources: boolean, whether to include URLs that redirect
as well as their final destination URLs
kwargs: passed to requests.head() when following redirects
Returns: ([string original post URLs], [string mention URLs]) tuple
"""
obj = activity.get("object") or activity
content = obj.get("content", "").strip()
# find all candidate URLs
tags = [
t.get("url")
for t in obj.get("attachments", []) + obj.get("tags", [])
if t.get("objectType") in ("article", "mention", None)
]
candidates = tags + util.extract_links(content) + obj.get("upstreamDuplicates", [])
# Permashortcitations (http://indiewebcamp.com/permashortcitation) are short
# references to canonical copies of a given (usually syndicated) post, of
# the form (DOMAIN PATH). We consider them an explicit original post link.
candidates += [match.expand(r"http://\1/\2") for match in Source._PERMASHORTCITATION_RE.finditer(content)]
candidates = set(
filter(
None,
(
util.clean_url(url)
for url in candidates
# heuristic: ellipsized URLs are probably incomplete, so omit them.
if url and not url.endswith("...") and not url.endswith(u"…")
),
)
)
# check for redirect and add their final urls
redirects = {} # maps final URL to original URL for redirects
for url in list(candidates):
resolved = follow_redirects(url, cache=cache, **kwargs)
if resolved.url != url and resolved.headers.get("content-type", "").startswith("text/html"):
redirects[resolved.url] = url
candidates.add(resolved.url)
# use domains to determine which URLs are original post links vs mentions
originals = set()
mentions = set()
for url in util.dedupe_urls(candidates):
if url in redirects.values():
# this is a redirected original URL. postpone and handle it when we hit
# its final URL so that we know the final domain.
continue
which = originals if not domains or util.domain_from_link(url) in domains else mentions
which.add(url)
redirected_from = redirects.get(url)
if redirected_from and include_redirect_sources:
which.add(redirected_from)
logging.info("Original post discovery found original posts %s, mentions %s", originals, mentions)
return originals, mentions
kwargs.setdefault("timeout", appengine_config.HTTP_TIMEOUT)
resolved = requests.head(url, allow_redirects=True, **kwargs)
resolved.raise_for_status()
if resolved.url != url:
logging.debug("Resolved %s to %s", url, resolved.url)
cache_time = 0 # forever
except AssertionError:
raise
except BaseException, e:
logging.warning("Couldn't resolve URL %s : %s", url, e)
resolved = requests.Response()
resolved.url = url
resolved.status_code = 499 # not standard. i made this up.
cache_time = FAILED_RESOLVE_URL_CACHE_TIME
content_type = resolved.headers.get("content-type")
if not content_type:
type, _ = mimetypes.guess_type(resolved.url)
resolved.headers["content-type"] = type or "text/html"
refresh = resolved.headers.get("refresh")
if refresh:
for part in refresh.split(";"):
if part.strip().startswith("url="):
return follow_redirects(part.strip()[4:], cache=cache, **kwargs)
resolved.url = util.clean_url(resolved.url)
if cache is not None:
cache.set_multi({cache_key: resolved, "R " + resolved.url: resolved}, time=cache_time)
return resolved
except AssertionError:
raise
except BaseException, e:
logging.warning("Couldn't resolve URL %s : %s", url, e)
resolved = requests.Response()
resolved.url = url
resolved.status_code = 499 # not standard. i made this up.
cache_time = FAILED_RESOLVE_URL_CACHE_TIME
content_type = resolved.headers.get('content-type')
if not content_type:
type, _ = mimetypes.guess_type(resolved.url)
resolved.headers['content-type'] = type or 'text/html'
refresh = resolved.headers.get('refresh')
if refresh:
for part in refresh.split(';'):
if part.strip().startswith('url='):
return follow_redirects(part.strip()[4:],
cache=cache,
**kwargs)
resolved.url = util.clean_url(resolved.url)
if cache is not None:
cache.set_multi({
cache_key: resolved,
'R ' + resolved.url: resolved
},
time=cache_time)
return resolved
