bridgy-fed/protocol.py

1267 wiersze
45 KiB
Python

"""Base protocol class and common code."""
import copy
import logging
import threading
from urllib.parse import urljoin
from cachetools import LRUCache
from flask import g, request
from google.cloud import ndb
from google.cloud.ndb import OR
from granary import as1
from oauth_dropins.webutil.flask_util import cloud_tasks_only
from oauth_dropins.webutil import util
from oauth_dropins.webutil.util import json_dumps, json_loads
import werkzeug.exceptions
import common
from common import add, DOMAIN_BLOCKLIST, DOMAINS, error, subdomain_wrap
from flask_app import app
from ids import translate_object_id, translate_user_id
from models import Follower, get_originals, Object, PROTOCOLS, Target, User
SUPPORTED_TYPES = (
'accept',
'article',
'audio',
'comment',
'delete',
'follow',
'image',
'like',
'note',
'post',
'share',
'stop-following',
'undo',
'update',
'video',
)
# activity ids that we've already handled and can now ignore.
# used in Protocol.receive
seen_ids = LRUCache(100000)
seen_ids_lock = threading.Lock()
# objects that have been loaded in Protocol.load
objects_cache = LRUCache(5000)
objects_cache_lock = threading.Lock()
logger = logging.getLogger(__name__)
# TODO: merge Protocol and User classes?
class Protocol:
"""Base protocol class. Not to be instantiated; classmethods only.
Attributes:
LABEL (str): human-readable lower case name
OTHER_LABELS (list of str): label aliases
ABBREV (str): lower case abbreviation, used in URL paths
LOGO_HTML (str): logo emoji or ``<img>`` tag
CONTENT_TYPE (str): MIME type of this protocol's native data format,
appropriate for the ``Content-Type`` HTTP header.
"""
ABBREV = None
OTHER_LABELS = ()
LOGO_HTML = ''
CONTENT_TYPE = None
def __init__(self):
assert False
@classmethod
@property
def LABEL(cls):
return cls.__name__.lower()
@staticmethod
def for_request(fed=None):
"""Returns the protocol for the current request.
...based on the request's hostname.
Args:
fed (str or protocol.Protocol): protocol to return if the current
request is on ``fed.brid.gy``
Returns:
Protocol: protocol, or None if the provided domain or request hostname
domain is not a subdomain of ``brid.gy`` or isn't a known protocol
"""
return Protocol.for_bridgy_subdomain(request.host, fed=fed)
@staticmethod
def for_bridgy_subdomain(domain_or_url, fed=None):
"""Returns the protocol for a brid.gy subdomain.
Args:
domain_or_url (str)
fed (str or protocol.Protocol): protocol to return if the current
request is on ``fed.brid.gy``
Returns:
class: :class:`Protocol` subclass, or None if the provided domain or request
hostname domain is not a subdomain of ``brid.gy`` or isn't a known
protocol
"""
domain = (util.domain_from_link(domain_or_url, minimize=False)
if util.is_web(domain_or_url)
else domain_or_url)
if domain == common.PRIMARY_DOMAIN or domain in common.LOCAL_DOMAINS:
return PROTOCOLS[fed] if isinstance(fed, str) else fed
elif domain and domain.endswith(common.SUPERDOMAIN):
label = domain.removesuffix(common.SUPERDOMAIN)
return PROTOCOLS.get(label)
@classmethod
def owns_id(cls, id):
"""Returns whether this protocol owns the id, or None if it's unclear.
To be implemented by subclasses.
IDs are string identities that uniquely identify users, and are intended
primarily to be machine readable and usable. Compare to handles, which
are human-chosen, human-meaningful, and often but not always unique.
Some protocols' ids are more or less deterministic based on the id
format, eg AT Protocol owns ``at://`` URIs. Others, like http(s) URLs,
could be owned by eg Web or ActivityPub.
This should be a quick guess without expensive side effects, eg no
external HTTP fetches to fetch the id itself or otherwise perform
discovery.
Returns False if the id's domain is in :const:`common.DOMAIN_BLOCKLIST`.
Args:
id (str)
Returns:
bool or None:
"""
return False
@classmethod
def owns_handle(cls, handle):
"""Returns whether this protocol owns the handle, or None if it's unclear.
To be implemented by subclasses.
Handles are string identities that are human-chosen, human-meaningful,
and often but not always unique. Compare to IDs, which uniquely identify
users, and are intended primarily to be machine readable and usable.
Some protocols' handles are more or less deterministic based on the id
format, eg ActivityPub (technically WebFinger) handles are
``@user@instance.com``. Others, like domains, could be owned by eg Web,
ActivityPub, AT Protocol, or others.
This should be a quick guess without expensive side effects, eg no
external HTTP fetches to fetch the id itself or otherwise perform
discovery.
Args:
handle (str)
Returns:
bool or None
"""
return False
@classmethod
def handle_to_id(cls, handle):
"""Converts a handle to an id.
To be implemented by subclasses.
May incur network requests, eg DNS queries or HTTP requests.
Args:
handle (str)
Returns:
str: corresponding id, or None if the handle can't be found
"""
raise NotImplementedError()
@classmethod
def key_for(cls, id):
"""Returns the :class:`google.cloud.ndb.Key` for a given id's :class:`models.User`.
To be implemented by subclasses. Canonicalizes the id if necessary.
If called via `Protocol.key_for`, infers the appropriate protocol with
:meth:`for_id`. If called with a concrete subclass, uses that subclass
as is.
Returns:
google.cloud.ndb.Key: matching key, or None if the given id is not a
valid :class:`User` id for this protocol.
"""
if cls == Protocol:
proto = Protocol.for_id(id)
return proto.key_for(id) if proto else None
# load user so that we follow use_instead
existing = cls.get_by_id(id)
if existing:
if existing.status == 'opt-out':
return None
return existing.key
return cls(id=id).key
@staticmethod
def for_id(id):
"""Returns the protocol for a given id.
May incur expensive side effects like fetching the id itself over the
network or other discovery.
Args:
id (str)
Returns:
Protocol subclass: matching protocol, or None if no known protocol
owns this id
"""
logger.info(f'Determining protocol for id {id}')
if not id:
return None
# step 1: check for our per-protocol subdomains
if util.is_web(id):
by_subdomain = Protocol.for_bridgy_subdomain(id)
if by_subdomain:
logger.info(f' {by_subdomain.LABEL} owns id {id}')
return by_subdomain
# step 2: check if any Protocols say conclusively that they own it
# sort to be deterministic
protocols = sorted(set(p for p in PROTOCOLS.values() if p),
key=lambda p: p.LABEL)
candidates = []
for protocol in protocols:
owns = protocol.owns_id(id)
if owns:
logger.info(f' {protocol.LABEL} owns id {id}')
return protocol
elif owns is not False:
candidates.append(protocol)
if len(candidates) == 1:
logger.info(f' {candidates[0].LABEL} owns id {id}')
return candidates[0]
# step 3: look for existing Objects in the datastore
obj = Protocol.load(id, remote=False)
if obj and obj.source_protocol:
logger.info(f' {obj.key} owned by source_protocol {obj.source_protocol}')
return PROTOCOLS[obj.source_protocol]
# step 4: fetch over the network
for protocol in candidates:
logger.info(f'Trying {protocol.LABEL}')
try:
if protocol.load(id, local=False, remote=True):
logger.info(f' {protocol.LABEL} owns id {id}')
return protocol
except werkzeug.exceptions.BadGateway:
# we tried and failed fetching the id over the network.
# this depends on ActivityPub.fetch raising this!
return None
except werkzeug.exceptions.HTTPException as e:
# internal error we generated ourselves; try next protocol
pass
except Exception as e:
code, _ = util.interpret_http_exception(e)
if code:
# we tried and failed fetching the id over the network
return None
raise
logger.info(f'No matching protocol found for {id} !')
return None
@staticmethod
def for_handle(handle):
"""Returns the protocol for a given handle.
May incur expensive side effects like resolving the handle itself over
the network or other discovery.
Args:
handle (str)
Returns:
(Protocol subclass, str) tuple: matching protocol and optional id (if
resolved), or ``(None, None)`` if no known protocol owns this handle
"""
# TODO: normalize, eg convert domains to lower case
logger.info(f'Determining protocol for handle {handle}')
if not handle:
return (None, None)
# step 1: check if any Protocols say conclusively that they own it.
# sort to be deterministic.
protocols = sorted(set(p for p in PROTOCOLS.values() if p),
key=lambda p: p.LABEL)
candidates = []
for proto in protocols:
owns = proto.owns_handle(handle)
if owns:
logger.info(f' {proto.LABEL} owns handle {handle}')
return (proto, None)
elif owns is not False:
candidates.append(proto)
if len(candidates) == 1:
logger.info(f' {candidates[0].LABEL} owns handle {handle}')
return (candidates[0], None)
# step 2: look for matching User in the datastore
for proto in candidates:
user = proto.query(proto.handle == handle).get()
if user:
if user.status == 'opt-out':
return (None, None)
logger.info(f' user {user.key} owns handle {handle}')
return (proto, user.key.id())
# step 3: resolve handle to id
for proto in candidates:
id = proto.handle_to_id(handle)
if id:
logger.info(f' {proto.LABEL} resolved handle {handle} to id {id}')
return (proto, id)
return (None, None)
@classmethod
def actor_key(cls, obj, default_g_user=True):
"""Returns the :class:`User`: key for a given object's author or actor.
If obj has no author or actor, defaults to g.user if it's set and
``default_g_user`` is True, otherwise None.
Args:
obj (models.Object)
default_g_user (bool)
Returns:
google.cloud.ndb.key.Key or None:
"""
owner = as1.get_owner(obj.as1)
if owner:
return cls.key_for(owner)
elif default_g_user and g.user and g.user.status != 'opt-out':
return g.user.key
@classmethod
def send(to_cls, obj, url, orig_obj=None):
"""Sends an outgoing activity.
To be implemented by subclasses.
Args:
obj (models.Object): with activity to send
url (str): destination URL to send to
orig_obj (models.Object): the "original object" that this object
refers to, eg replies to or reposts or likes
Returns:
bool: True if the activity is sent successfully, False if it is
ignored or otherwise unsent due to protocol logic, eg no webmention
endpoint, protocol doesn't support the activity type. (Failures are
raised as exceptions.)
Raises:
werkzeug.HTTPException if the request fails
"""
raise NotImplementedError()
@classmethod
def fetch(cls, obj, **kwargs):
"""Fetches a protocol-specific object and populates it in an :class:`Object`.
Errors are raised as exceptions. If this method returns False, the fetch
didn't fail but didn't succeed either, eg the id isn't valid for this
protocol, or the fetch didn't return valid data for this protocol.
To be implemented by subclasses.
Args:
obj (models.Object): with the id to fetch. Data is filled into one of
the protocol-specific properties, eg ``as2``, ``mf2``, ``bsky``.
kwargs: subclass-specific
Returns:
bool: True if the object was fetched and populated successfully,
False otherwise
Raises:
werkzeug.HTTPException: if the fetch fails
"""
raise NotImplementedError()
@classmethod
def convert(cls, obj):
"""Converts an :class:`Object` to this protocol's data format.
For example, an HTML string for :class:`Web`, or a dict with AS2 JSON
and ``application/activity+json`` for :class:`ActivityPub`.
To be implemented by subclasses. Implementations should generally call
:meth:`Protocol.translate_ids` (as their own class) before converting to
their format.
Args:
obj (models.Object):
Returns:
converted object in the protocol's native format, often a dict
"""
raise NotImplementedError()
@classmethod
def target_for(cls, obj, shared=False):
"""Returns an :class:`Object`'s delivery target (endpoint).
To be implemented by subclasses.
Examples:
* If obj has ``source_protocol`` ``web``, returns its URL, as a
webmention target.
* If obj is an ``activitypub`` actor, returns its inbox.
* If obj is an ``activitypub`` object, returns it's author's or actor's
inbox.
Args:
obj (models.Object):
shared (bool): optional. If True, returns a common/shared
endpoint, eg ActivityPub's ``sharedInbox``, that can be reused for
multiple recipients for efficiency
Returns:
str: target endpoint, or None if not available.
"""
raise NotImplementedError()
@classmethod
def is_blocklisted(cls, url):
"""Returns True if we block the given URL and shouldn't deliver to it.
Default implementation here, subclasses may override.
Args:
url (str):
Returns: bool:
"""
return util.domain_or_parent_in(util.domain_from_link(url),
DOMAIN_BLOCKLIST + DOMAINS)
@classmethod
def translate_ids(to_cls, obj):
"""Wraps ids and actors in an AS1 object in subdomain convert URLs.
Infers source protocol for each id value separately.
For example, if ``proto`` is :class:`ActivityPub`, the ATProto URI
``at://did:plc:abc/coll/123`` will be converted to
``https://atproto.brid.gy/ap/at://did:plc:abc/coll/123``.
Wraps these AS1 fields:
* ``id``
* ``actor``
* ``author``
* ``object``
* ``object.actor``
* ``object.author``
* ``object.id``
* ``object.inReplyTo``
* ``tags.[objectType=mention].url``
This is the inverse of :meth:`models.Object.resolve_ids`. Much of the
same logic is duplicated there!
Args:
to_proto (Protocol subclass)
obj (dict): AS1 object or activity (not :class:`models.Object`!)
Returns:
dict: wrapped version of ``obj``
"""
assert to_cls != Protocol
if not obj:
return obj
outer_obj = copy.deepcopy(obj)
inner_obj = outer_obj['object'] = as1.get_object(outer_obj)
def translate(elem, field, fn):
elem[field] = as1.get_object(elem, field)
id = elem[field].get('id')
if id and util.domain_from_link(id) not in DOMAINS:
from_cls = Protocol.for_id(id)
# TODO: what if from_cls is None? relax translate_object_id,
# make it a noop if we don't know enough about from/to?
if from_cls and from_cls != to_cls:
elem[field]['id'] = fn(id=id, from_proto=from_cls, to_proto=to_cls)
if elem[field].keys() == {'id'}:
elem[field] = elem[field]['id']
type = as1.object_type(outer_obj)
translate(outer_obj, 'id',
translate_user_id if type in as1.ACTOR_TYPES
else translate_object_id)
inner_is_actor = (as1.object_type(inner_obj) in as1.ACTOR_TYPES
or type in ('follow', 'stop-following'))
translate(inner_obj, 'id',
translate_user_id if inner_is_actor else translate_object_id)
for o in outer_obj, inner_obj:
translate(o, 'inReplyTo', translate_object_id)
for field in 'actor', 'author':
translate(o, field, translate_user_id)
for tag in as1.get_objects(o, 'tags'):
if tag.get('objectType') == 'mention':
translate(tag, 'url', translate_user_id)
outer_obj = util.trim_nulls(outer_obj)
if outer_obj.get('object', {}).keys() == {'id'}:
outer_obj['object'] = inner_obj['id']
return outer_obj
@classmethod
def receive(from_cls, obj, authed_as=None):
"""Handles an incoming activity.
If ``obj``'s key is unset, ``obj.as1``'s id field is used. If both are
unset, raises :class:`werkzeug.exceptions.BadRequest`.
Args:
obj (models.Object)
Returns:
(str, int) tuple: (response body, HTTP status code) Flask response
Raises:
werkzeug.HTTPException: if the request is invalid
"""
# check some invariants
assert from_cls != Protocol
assert isinstance(obj, Object), obj
logger.info(f'From {from_cls.LABEL}: {obj.key} AS1: {json_dumps(obj.as1, indent=2)}')
if not obj.as1:
error('No object data provided')
id = None
if obj.key and obj.key.id():
id = obj.key.id()
if not id:
id = obj.as1.get('id')
obj.key = ndb.Key(Object, id)
if not id:
error('No id provided')
# short circuit if we've already seen this activity id.
# (don't do this for bare objects since we need to check further down
# whether they've been updated since we saw them last.)
if obj.as1.get('objectType') == 'activity' and 'force' not in request.values:
with seen_ids_lock:
already_seen = id in seen_ids
seen_ids[id] = True
if (already_seen
or (obj.new is False and obj.changed is False)
or (obj.new is None and obj.changed is None
and from_cls.load(id, remote=False))):
msg = f'Already handled this activity {id}'
logger.info(msg)
return msg, 204
# authorization check
actor = as1.get_owner(obj.as1)
if authed_as and actor != authed_as:
logger.warning(f"actor {actor} isn't authed user {authed_as}")
# update copy ids to originals
obj.resolve_ids()
# write Object to datastore
orig = obj
obj = Object.get_or_create(id, **orig.to_dict(), actor=actor)
if orig.new is not None:
obj.new = orig.new
if orig.changed is not None:
obj.changed = orig.changed
# if this is a post, ie not an activity, wrap it in a create or update
obj = from_cls.handle_bare_object(obj)
if obj.type not in SUPPORTED_TYPES:
error(f'Sorry, {obj.type} activities are not supported yet.', status=501)
# add owner(s)
# (actor_key returns None if the user is opted out)
actor_key = from_cls.actor_key(obj, default_g_user=False)
if actor_key:
obj.add('users', actor_key)
if not g.user:
g.user = from_cls.get_or_create(id=actor_key.id())
inner_obj_as1 = as1.get_object(obj.as1)
if obj.as1.get('verb') in ('post', 'update', 'delete'):
inner_actor = as1.get_owner(inner_obj_as1)
if inner_actor:
user_key = from_cls.key_for(inner_actor)
if user_key:
obj.add('users', user_key)
obj.source_protocol = from_cls.LABEL
obj.put()
# store inner object
inner_obj_id = inner_obj_as1.get('id')
if obj.type in ('post', 'update') and inner_obj_as1.keys() > set(['id']):
Object.get_or_create(inner_obj_id, our_as1=inner_obj_as1,
source_protocol=from_cls.LABEL, actor=actor)
actor = as1.get_object(obj.as1, 'actor')
actor_id = actor.get('id')
# handle activity!
if obj.type == 'accept': # eg in response to a Follow
return 'OK' # noop
elif obj.type == 'stop-following':
# TODO: unify with handle_follow?
# TODO: handle multiple followees
if not actor_id or not inner_obj_id:
error(f'Undo of Follow requires actor id and object id. Got: {actor_id} {inner_obj_id} {obj.as1}')
# deactivate Follower
# TODO: avoid import?
from web import Web
from_ = from_cls.key_for(actor_id)
to_cls = Protocol.for_id(inner_obj_id) or Web
to = to_cls.key_for(inner_obj_id)
follower = Follower.query(Follower.to == to,
Follower.from_ == from_,
Follower.status == 'active').get()
if follower:
logger.info(f'Marking {follower} inactive')
follower.status = 'inactive'
follower.put()
else:
logger.warning(f'No Follower found for {from_} => {to}')
# fall through to deliver to followee
# TODO: do we convert stop-following to webmention 410 of original
# follow?
elif obj.type in ('update', 'like', 'share'): # require object
if not inner_obj_id:
error("Couldn't find id of object to update")
# fall through to deliver to followers
elif obj.type == 'delete':
if not inner_obj_id:
error("Couldn't find id of object to delete")
logger.info(f'Marking Object {inner_obj_id} deleted')
Object.get_or_create(inner_obj_id, deleted=True)
# if this is an actor, deactivate its followers/followings
# https://github.com/snarfed/bridgy-fed/issues/63
deleted_user = from_cls.key_for(id=inner_obj_id)
if deleted_user:
logger.info(f'Deactivating Followers from or to = {inner_obj_id}')
followers = Follower.query(OR(Follower.to == deleted_user,
Follower.from_ == deleted_user)
).fetch()
for f in followers:
f.status = 'inactive'
ndb.put_multi(followers)
# fall through to deliver to followers
# fetch actor if necessary so we have name, profile photo, etc
if actor and actor.keys() == set(['id']):
logger.info('Fetching actor so we have name, profile photo, etc')
actor_obj = from_cls.load(actor['id'])
if actor_obj and actor_obj.as1:
obj.our_as1 = {**obj.as1, 'actor': actor_obj.as1}
# fetch object if necessary so we can render it in feeds
if (obj.type == 'share'
and inner_obj_as1.keys() == set(['id'])
and from_cls.owns_id(inner_obj_id)):
logger.info('Fetching object so we can render it in feeds')
inner_obj = from_cls.load(inner_obj_id)
if inner_obj and inner_obj.as1:
obj.our_as1 = {
**obj.as1,
'object': {
**inner_obj_as1,
**inner_obj.as1,
}
}
if obj.type == 'follow':
from_cls.handle_follow(obj)
# deliver to targets
return from_cls.deliver(obj)
@classmethod
def handle_follow(from_cls, obj):
"""Handles an incoming follow activity.
Sends an ``Accept`` back, but doesn't send the ``Follow`` itself. That
happens in :meth:`deliver`.
Args:
obj (models.Object): follow activity
"""
logger.info('Got follow. Loading users, storing Follow(s), sending accept(s)')
# Prepare follower (from) users' data
from_as1 = as1.get_object(obj.as1, 'actor')
from_id = from_as1.get('id')
if not from_id:
error(f'Follow activity requires actor. Got: {obj.as1}')
from_obj = from_cls.load(from_id)
if not from_obj:
error(f"Couldn't load {from_id}")
if not from_obj.as1:
from_obj.our_as1 = from_as1
from_obj.put()
from_target = from_cls.target_for(from_obj)
if not from_target:
error(f"Couldn't find delivery target for follower {from_obj}")
from_key = from_cls.key_for(from_id)
if not from_key:
error(f'Invalid {from_cls} user key: {from_id}')
obj.users = [from_key]
# Prepare followee (to) users' data
to_as1s = as1.get_objects(obj.as1)
if not to_as1s:
error(f'Follow activity requires object(s). Got: {obj.as1}')
# Store Followers
for to_as1 in to_as1s:
to_id = to_as1.get('id')
if not to_id or not from_id:
error(f'Follow activity requires object(s). Got: {obj.as1}')
from_user = from_cls.get_or_create(id=from_key.id(), obj=from_obj)
logger.info(f'Follow {from_id} => {to_id}')
to_cls = Protocol.for_id(to_id)
if not to_cls:
error(f"Couldn't determine protocol for {to_id}")
elif from_cls == to_cls and from_cls.LABEL != 'fake':
logger.info(f'Skipping same-protocol Follower {from_id} => {to_id}')
continue
to_obj = to_cls.load(to_id)
if to_obj and not to_obj.as1:
to_obj.our_as1 = to_as1
to_obj.put()
# If followee user is already direct, follower may not know they're
# interacting with a bridge. if followee user is indirect though,
# follower should know, so they're direct.
to_key = to_cls.key_for(to_id)
if not to_key:
logger.info(f'Skipping invalid {from_cls} user key: {from_id}')
continue
to_user = to_cls.get_or_create(id=to_key.id(), obj=to_obj, direct=False)
# HACK: we rewrite direct here for each followee, so the last one
# wins. Could we do something better?
from_user = from_cls.get_or_create(id=from_key.id(), obj=from_obj,
direct=not to_user.direct)
follower_obj = Follower.get_or_create(to=to_user, from_=from_user,
follow=obj.key, status='active')
obj.add('notify', to_key)
# send accept. note that this is one accept for the whole follow, even
# if it has multiple followees!
id = to_user.ap_actor(f'followers#accept-{obj.key.id()}')
accept = Object.get_or_create(id, our_as1={
'id': id,
'objectType': 'activity',
'verb': 'accept',
'actor': to_id,
'object': obj.as1,
})
# TODO: ugly, brittle. dangerous. remove once postprocess_as2 no
# longer depends on g.user!
# https://github.com/snarfed/bridgy-fed/issues/690
orig_g_user = g.user
g.user = to_user
sent = from_cls.send(accept, from_target)
g.user = orig_g_user
if sent:
accept.populate(
delivered=[Target(protocol=from_cls.LABEL, uri=from_target)],
status='complete',
)
accept.put()
@classmethod
def handle_bare_object(cls, obj):
"""If obj is a bare object, wraps it in a create or update activity.
Checks if we've seen it before.
Args:
obj (models.Object)
Returns:
models.Object: ``obj`` if it's an activity, otherwise a new object
"""
if obj.type not in ('note', 'article', 'comment'):
return obj
obj_actor = as1.get_owner(obj.as1)
now = util.now().isoformat()
# this is a raw post; wrap it in a create or update activity
if obj.changed:
logger.info(f'Content has changed from last time at {obj.updated}! Redelivering to all inboxes')
id = f'{obj.key.id()}#bridgy-fed-update-{now}'
update_as1 = {
'objectType': 'activity',
'verb': 'update',
'id': id,
'actor': obj_actor,
'object': {
# Mastodon requires the updated field for Updates, so
# add a default value.
# https://docs.joinmastodon.org/spec/activitypub/#supported-activities-for-statuses
# https://socialhub.activitypub.rocks/t/what-could-be-the-reason-that-my-update-activity-does-not-work/2893/4
# https://github.com/mastodon/documentation/pull/1150
'updated': now,
**obj.as1,
},
}
logger.info(f'Wrapping in update: {json_dumps(update_as1, indent=2)}')
return Object(id=id, our_as1=update_as1,
source_protocol=obj.source_protocol)
create_id = f'{obj.key.id()}#bridgy-fed-create'
create = cls.load(create_id, remote=False)
if (obj.new or not create or create.status != 'complete'
# HACK: force query param here is specific to webmention
or 'force' in request.form):
if create:
logger.info(f'Existing create {create.key} status {create.status}')
else:
logger.info(f'No existing create activity')
create_as1 = {
'objectType': 'activity',
'verb': 'post',
'id': create_id,
'actor': obj_actor,
'object': obj.as1,
'published': now,
}
logger.info(f'Wrapping in post: {json_dumps(create_as1, indent=2)}')
return Object.get_or_create(create_id, our_as1=create_as1,
source_protocol=obj.source_protocol)
error(f'{obj.key.id()} is unchanged, nothing to do', status=204)
@classmethod
def deliver(from_cls, obj):
"""Delivers an activity to its external recipients.
Args:
obj (models.Object): activity to deliver
"""
# find delivery targets
# sort targets so order is deterministic for tests, debugging, etc
targets = from_cls.targets(obj) # maps Target to Object or None
if not targets:
obj.status = 'ignored'
obj.put()
error('No targets, nothing to do ¯\_(ツ)_/¯', status=204)
sorted_targets = sorted(targets.items(), key=lambda t: t[0].uri)
obj.populate(
status='in progress',
delivered=[],
failed=[],
undelivered=[t for t, _ in sorted_targets],
)
obj.put()
logger.info(f'Delivering to: {obj.undelivered}')
# enqueue send task for each targets
for i, (target, orig_obj) in enumerate(sorted_targets):
orig_obj = orig_obj.key.urlsafe() if orig_obj else ''
user = g.user.key.urlsafe() if g.user else ''
common.create_task(queue='send', obj=obj.key.urlsafe(),
url=target.uri, protocol=target.protocol,
orig_obj=orig_obj, user=user)
return 'OK', 202
@classmethod
def targets(cls, obj):
"""Collects the targets to send a :class:`models.Object` to.
Targets are both objects - original posts, events, etc - and actors.
Args:
obj (models.Object)
Returns:
dict: maps :class:`models.Target` to original (in response to)
:class:`models.Object`, if any, otherwise None
"""
logger.info('Finding recipients and their targets')
target_uris = set(as1.targets(obj.as1))
logger.info(f'Raw targets: {target_uris}')
# TODO: remove this? seems unnecessary now that receive calls resolve_ids?
if target_uris:
origs = {key.id() for key in get_originals(target_uris, keys_only=True)}
if origs:
target_uris |= origs
logger.info(f'Added originals: {origs}')
orig_obj = None
targets = {} # maps Target to Object or None
in_reply_to = as1.get_object(obj.as1).get('inReplyTo')
is_self_reply = False
owner = as1.get_owner(obj.as1)
for id in sorted(target_uris):
protocol = Protocol.for_id(id)
if not protocol:
logger.info(f"Can't determine protocol for {id}")
continue
elif protocol == cls and cls.LABEL != 'fake':
logger.info(f'Skipping same-protocol target {id}')
continue
elif protocol.is_blocklisted(id):
logger.info(f'{id} is blocklisted')
continue
orig_obj = protocol.load(id)
if not orig_obj or not orig_obj.as1:
logger.info(f"Couldn't load {id}")
continue
# deliver self-replies to followers
# https://github.com/snarfed/bridgy-fed/issues/639
if owner == as1.get_owner(orig_obj.as1):
is_self_reply = True
logger.info(f'Looks like a self reply! Delivering to all followers')
target = protocol.target_for(orig_obj)
if not target:
# TODO: surface errors like this somehow?
logger.error(f"Can't find delivery target for {id}")
continue
logger.info(f'Target for {id} is {target}')
targets[Target(protocol=protocol.LABEL, uri=target)] = orig_obj
orig_user = protocol.actor_key(orig_obj, default_g_user=False)
if orig_user:
logger.info(f'Recipient is {orig_user}')
obj.add('notify', orig_user)
logger.info(f'Direct targets: {targets.keys()}')
# deliver to followers, if appropriate
user_key = cls.actor_key(obj, default_g_user=False)
if not user_key:
logger.info("Can't tell who this is from! Skipping followers.")
return targets
is_reply = obj.type == 'comment' or in_reply_to
if (obj.type in ('post', 'update', 'delete', 'share')
and (is_self_reply or not is_reply)):
logger.info(f'Delivering to followers of {user_key}')
followers = Follower.query(Follower.to == user_key,
Follower.status == 'active'
).fetch()
users = [u for u in ndb.get_multi(f.from_ for f in followers) if u]
User.load_multi(users)
# which object should we add to followers' feeds, if any
feed_obj = None
if obj.type == 'share':
feed_obj = obj
else:
inner = as1.get_object(obj.as1)
# don't add profile updates to feeds
if not (obj.type == 'update'
and inner.get('objectType') in as1.ACTOR_TYPES):
inner_id = inner.get('id')
if inner_id:
feed_obj = cls.load(inner_id)
for user in users:
if feed_obj:
feed_obj.add('feed', user.key)
# TODO: should we pass remote=False through here to Protocol.load?
target = user.target_for(user.obj, shared=True) if user.obj else None
if not target:
# TODO: surface errors like this somehow?
logger.error(f'Follower {user.key} has no delivery target')
continue
# normalize URL (lower case hostname, etc)
target = util.dedupe_urls([target])[0]
# HACK: use last target object from above for reposts, which
# has its resolved id
targets[Target(protocol=user.LABEL, uri=target)] = \
orig_obj if obj.as1.get('verb') == 'share' else None
if feed_obj:
feed_obj.put()
# de-dupe targets, discard same-domain
candidates = {t.uri: (t, obj) for t, obj in targets.items()}
targets = {}
source_domains = [
util.domain_from_link(url) for url in
(obj.as1.get('id'), obj.as1.get('url'), as1.get_owner(obj.as1))
if util.is_web(url)
]
for url in sorted(util.dedupe_urls(candidates.keys())):
if util.is_web(url) and util.domain_from_link(url) in source_domains:
logger.info(f'Skipping same-domain target {url}')
else:
target, obj = candidates[url]
targets[target] = obj
return targets
@classmethod
def load(cls, id, remote=None, local=True, **kwargs):
"""Loads and returns an Object from memory cache, datastore, or HTTP fetch.
Sets the :attr:`new` and :attr:`changed` attributes if we know either
one for the loaded object, ie local is True and remote is True or None.
Note that :meth:`Object._post_put_hook` updates the cache.
Args:
id (str)
remote (bool): whether to fetch the object over the network. If True,
fetches even if we already have the object stored, and updates our
stored copy. If False and we don't have the object stored, returns
None. Default (None) means to fetch over the network only if we
don't already have it stored.
local (bool): whether to load from the datastore before
fetching over the network. If False, still stores back to the
datastore after a successful remote fetch.
kwargs: passed through to :meth:`fetch()`
Returns:
models.Object: loaded object, or None if it isn't fetchable, eg a
non-URL string for Web, or ``remote`` is False and it isn't in the
cache or datastore
Raises:
requests.HTTPError: anything that :meth:`fetch` raises
"""
assert local or remote is not False
if remote is not True:
with objects_cache_lock:
cached = objects_cache.get(id)
if cached:
# make a copy so that if the client modifies this entity in
# memory, those modifications aren't applied to the cache
# until they explicitly put() the modified entity.
# NOTE: keep in sync with Object._post_put_hook!
return Object(id=cached.key.id(), **cached.to_dict(
# computed properties
exclude=['as1', 'expire', 'object_ids', 'type']))
obj = orig_as1 = None
if local:
obj = Object.get_by_id(id)
if obj and (obj.as1 or obj.raw or obj.deleted):
logger.info(' got from datastore')
obj.new = False
orig_as1 = obj.as1
if remote is not True:
with objects_cache_lock:
objects_cache[id] = obj
return obj
if remote is True:
logger.debug(f'Loading Object {id} local={local} remote={remote}, forced refresh requested')
elif remote is False:
logger.debug(f'Loading Object {id} local={local} remote={remote} {"empty" if obj else "not"} in datastore')
return obj
if obj:
obj.clear()
obj.new = False
else:
obj = Object(id=id)
if local:
logger.info(' not in datastore')
obj.new = True
obj.changed = False
fetched = cls.fetch(obj, **kwargs)
if not fetched:
return None
obj.resolve_ids()
if obj.new is False:
obj.changed = obj.activity_changed(orig_as1)
obj.source_protocol = cls.LABEL
# TODO: drop this?
obj.put()
with objects_cache_lock:
objects_cache[id] = obj
return obj
@app.post('/queue/receive')
@cloud_tasks_only
def receive_task():
"""Task handler for a newly received :class:`models.Object`.
Calls :meth:`Protocol.receive` with the form parameters.
Parameters:
obj (url-safe google.cloud.ndb.key.Key): :class:`models.Object` to handle
user (url-safe google.cloud.ndb.key.Key): :class:`models.User` this
activity is on behalf of. This user will be loaded into ``g.user``
authed_as (str): passed to :meth:`Protocol.receive`
TODO: migrate incoming webmentions and AP inbox deliveries to this. The
difficulty is that parts of :meth:`protocol.Protocol.receive` depend on
setup in :func:`web.webmention` and :func:`activitypub.inbox`, eg
:class:`models.Object` with ``new`` and ``changed``, ``g.user`` (which
:meth:`Protocol.receive` now loads), HTTP request details, etc. See stash
for attempt at this for :class:`web.Web`.
"""
form = request.form.to_dict()
logger.info(f'Params: {list(form.items())}')
obj = ndb.Key(urlsafe=form['obj']).get()
assert obj
obj.new = True
if user_key := form.get('user'):
g.user = ndb.Key(urlsafe=user_key).get()
logger.info(f'setting g.user to {g.user.key}')
authed_as = form.get('authed_as')
try:
return PROTOCOLS[obj.source_protocol].receive(obj=obj, authed_as=authed_as)
except ValueError as e:
logger.warning(e, exc_info=True)
error(e, status=304)
@app.post('/queue/send')
@cloud_tasks_only
def send_task():
"""Task handler for sending an activity to a single specific destination.
Calls :meth:`Protocol.send` with the form parameters.
Parameters:
protocol (str): :class:`Protocol` to send to
url (str): destination URL to send to
obj (url-safe google.cloud.ndb.key.Key): :class:`models.Object` to send
orig_obj (url-safe google.cloud.ndb.key.Key): optional "original object"
:class:`models.Object` that this object refers to, eg replies to or
reposts or likes
user (url-safe google.cloud.ndb.key.Key): :class:`models.User` this
activity is on behalf of. This user will be loaded into ``g.user``
"""
form = request.form.to_dict()
logger.info(f'Params: {list(form.items())}')
# prepare
url = form['url']
protocol = form['protocol']
target = Target(uri=url, protocol=protocol)
obj = ndb.Key(urlsafe=form['obj']).get()
if (target not in obj.undelivered and target not in obj.failed
and 'force' not in request.values):
logger.info(f"{url} not in {obj.key.id()} undelivered or failed, giving up")
return '¯\_(ツ)_/¯', 204
if user_key := form.get('user'):
g.user = ndb.Key(urlsafe=user_key).get()
orig_obj = (ndb.Key(urlsafe=form['orig_obj']).get()
if form.get('orig_obj') else None)
# send
sent = None
try:
sent = PROTOCOLS[protocol].send(obj, url, orig_obj=orig_obj)
except BaseException as e:
code, body = util.interpret_http_exception(e)
if not code and not body:
logger.info(str(e), exc_info=True)
# write results to Object
@ndb.transactional()
def update_object(obj_key):
obj = obj_key.get()
if target in obj.undelivered:
obj.remove('undelivered', target)
if sent is None:
obj.add('failed', target)
else:
if target in obj.failed:
obj.remove('failed', target)
if sent:
obj.add('delivered', target)
if not obj.undelivered:
obj.status = ('complete' if obj.delivered
else 'failed' if obj.failed
else 'ignored')
obj.put()
update_object(obj.key)
return '', 200 if sent else 304