bridgy-fed/activitypub.py

295 wiersze
10 KiB
Python

"""Handles requests for ActivityPub endpoints: actors, inbox, etc.
"""
import datetime
import logging
import re
from flask import request
from google.cloud import ndb
from google.cloud.ndb import OR
from granary import as2
from oauth_dropins.webutil import flask_util, util
from oauth_dropins.webutil.flask_util import error
from oauth_dropins.webutil.util import json_dumps, json_loads
from app import app, cache
import common
from common import CACHE_TIME, redirect_unwrap, redirect_wrap
from models import Activity, Follower, User
logger = logging.getLogger(__name__)
SUPPORTED_TYPES = (
'Accept',
'Announce',
'Article',
'Audio',
'Create',
'Delete',
'Follow',
'Image',
'Like',
'Note',
'Undo',
'Video',
)
@app.get(f'/<regex("{common.DOMAIN_RE}"):domain>')
@flask_util.cached(cache, CACHE_TIME, http_5xx=True)
def actor(domain):
"""Fetches a domain's h-card and converts to AS2 actor."""
_, _, actor, _ = common.actor(domain)
return (actor, {
'Content-Type': as2.CONTENT_TYPE,
'Access-Control-Allow-Origin': '*',
})
@app.post('/inbox')
@app.post(f'/<regex("{common.DOMAIN_RE}"):domain>/inbox')
def inbox(domain=None):
"""Handles ActivityPub inbox delivery."""
body = request.get_data(as_text=True)
logger.info(f'Got: {body}')
# parse and validate AS2 activity
try:
activity = request.json
assert activity
except (TypeError, ValueError, AssertionError):
error(f"Couldn't parse body as JSON", exc_info=True)
type = activity.get('type')
actor = activity.get('actor')
actor_id = actor.get('id') if isinstance(actor, dict) else actor
logger.info(f'Got {type} activity from {actor_id}: {json_dumps(activity, indent=2)}')
obj = activity.get('object') or {}
if isinstance(obj, str):
obj = {'id': obj}
if type == 'Accept': # eg in response to a Follow
return '' # noop
if type not in SUPPORTED_TYPES:
error(f'Sorry, {type} activities are not supported yet.', status=501)
# TODO: verify signature if there is one
if type == 'Undo' and obj.get('type') == 'Follow':
# skip actor fetch below; we don't need it to undo a follow
undo_follow(redirect_unwrap(activity))
return ''
elif type == 'Delete':
# we currently only actually delete followers for Deletes that are sent
# to the shared inbox, not individual users' inboxes, to help scaling
# background: https://github.com/snarfed/bridgy-fed/issues/284
if domain:
logger.info('Skipping Delete sent to individual user inbox')
return 'OK'
id = obj.get('id') if isinstance(obj, dict) else obj
if not isinstance(id, str):
error("Couldn't find id of object to delete")
# assume this is an actor
# https://github.com/snarfed/bridgy-fed/issues/63
logger.info(f'Deactivating Followers with src or dest = {id}')
followers = Follower.query(OR(Follower.src == id,
Follower.dest == id)
).fetch()
for f in followers:
f.status = 'inactive'
ndb.put_multi(followers)
return 'OK'
user = User.get_or_create(domain) if domain else None
# fetch actor if necessary so we have name, profile photo, etc
if actor and isinstance(actor, str):
actor = activity['actor'] = common.get_as2(actor, user=user).json()
activity_unwrapped = redirect_unwrap(activity)
if type == 'Follow':
return accept_follow(activity, activity_unwrapped, user)
# send webmentions to each target
as1 = as2.to_as1(activity)
source_as2 = json_dumps(activity_unwrapped)
sent = common.send_webmentions(as1, proxy=True, protocol='activitypub',
source_as2=source_as2)
if not sent and type in ('Create', 'Announce'):
# check that this activity is public. only do this check for Creates,
# not Like, Follow, or other activity types, since Mastodon doesn't
# currently mark those as explicitly public.
if not as2.is_public(activity_unwrapped):
logging.info('Dropping non-public activity')
return ''
# normal post, deliver to BF followers
source = util.get_first(activity, 'url') or activity.get('id')
domains = []
if actor:
actor_id = actor.get('id')
if actor_id:
logging.info(f'Finding followers of {actor_id}')
domains = [f.src for f in
Follower.query(Follower.dest == actor_id,
projection=[Follower.src]).fetch()]
key = Activity(source=source, target='Public', direction='in',
protocol='activitypub', domain=domains, status='complete',
source_as2=source_as2).put()
logging.info(f'Wrote Activity {key} with {len(domains)} follower domains')
return ''
def accept_follow(follow, follow_unwrapped, user):
"""Replies to an AP Follow request with an Accept request.
Args:
follow: dict, AP Follow activity
follow_unwrapped: dict, same, except with redirect URLs unwrapped
user: :class:`User`
"""
logger.info('Replying to Follow with Accept')
followee = follow.get('object')
followee_unwrapped = follow_unwrapped.get('object')
followee_id = (followee_unwrapped.get('id')
if isinstance(followee_unwrapped, dict) else followee_unwrapped)
follower = follow.get('actor')
if not followee or not followee_id or not follower:
error(f'Follow activity requires object and actor. Got: {follow}')
inbox = follower.get('inbox')
follower_id = follower.get('id')
if not inbox or not follower_id:
error(f'Follow actor requires id and inbox. Got: {follower}')
# rendered mf2 HTML proxy pages (in render.py) fall back to redirecting to
# the follow's AS2 id field, but Mastodon's ids are URLs that don't load in
# browsers, eg https://jawns.club/ac33c547-ca6b-4351-80d5-d11a6879a7b0
# so, set a synthetic URL based on the follower's profile.
# https://github.com/snarfed/bridgy-fed/issues/336
follower_url = util.get_url(follower) or follower_id
followee_url = util.get_url(followee_unwrapped) or followee_id
follow_unwrapped.setdefault('url', f'{follower_url}#followed-{followee_url}')
# store Follower
followee_domain = util.domain_from_link(followee_id, minimize=False)
# follow use_instead, if any
followee_domain = User.get_or_create(followee_domain).key.id()
follower = Follower.get_or_create(dest=followee_domain, src=follower_id,
last_follow=json_dumps(follow))
follower.status = 'active'
follower.put()
# send AP Accept
accept = {
'@context': 'https://www.w3.org/ns/activitystreams',
'id': util.tag_uri(common.PRIMARY_DOMAIN,
f'accept/{followee_domain}/{follow.get("id")}'),
'type': 'Accept',
'actor': followee,
'object': {
'type': 'Follow',
'actor': follower_id,
'object': followee,
}
}
resp = common.signed_post(inbox, data=accept, user=user)
# send webmention
common.send_webmentions(as2.to_as1(follow), proxy=True, protocol='activitypub',
source_as2=json_dumps(follow_unwrapped))
return resp.text, resp.status_code
@ndb.transactional()
def undo_follow(undo_unwrapped):
"""Handles an AP Undo Follow request by deactivating the Follower entity.
Args:
undo_unwrapped: dict, AP Undo activity with redirect URLs unwrapped
"""
logger.info('Undoing Follow')
follow = undo_unwrapped.get('object', {})
follower = follow.get('actor')
followee = follow.get('object')
if isinstance(followee, dict):
followee = followee.get('id') or util.get_url(followee)
if not follower or not followee:
error(f'Undo of Follow requires object with actor and object. Got: {follow}')
# deactivate Follower
user_domain = util.domain_from_link(followee, minimize=False)
follower_obj = Follower.get_by_id(Follower._id(dest=user_domain, src=follower))
if follower_obj:
logger.info(f'Marking {follower_obj.key} as inactive')
follower_obj.status = 'inactive'
follower_obj.put()
else:
logger.warning(f'No Follower found for {user_domain} {follower}')
# TODO send webmention with 410 of u-follow
@app.get(f'/<regex("{common.DOMAIN_RE}"):domain>/<any(followers,following):collection>')
@flask_util.cached(cache, CACHE_TIME)
def follower_collection(domain, collection):
"""ActivityPub Followers and Following collections.
https://www.w3.org/TR/activitypub/#followers
https://www.w3.org/TR/activitypub/#collections
https://www.w3.org/TR/activitystreams-core/#paging
"""
if not User.get_by_id(domain):
return f'User {domain} not found', 404
# page
followers, new_before, new_after = common.fetch_followers(domain, collection)
items = []
for f in followers:
f_as2 = f.to_as2()
if f_as2:
items.append(f_as2)
page = {
'type': 'CollectionPage',
'partOf': request.base_url,
'items': items,
}
if new_before:
page['next'] = f'{request.base_url}?before={new_before}'
if new_after:
page['prev'] = f'{request.base_url}?after={new_after}'
if 'before' in request.args or 'after' in request.args:
page.update({
'@context': 'https://www.w3.org/ns/activitystreams',
'id': request.url,
})
logger.info(f'Returning {json_dumps(page, indent=2)}')
return page, {'Content-Type': as2.CONTENT_TYPE}
# collection
domain_prop = Follower.dest if collection == 'followers' else Follower.src
count = Follower.query(
Follower.status == 'active',
domain_prop == domain,
).count()
collection = {
'@context': 'https://www.w3.org/ns/activitystreams',
'id': request.base_url,
'type': 'Collection',
'summary': f"{domain}'s {collection}",
'totalItems': count,
'first': page,
}
logger.info(f'Returning {json_dumps(collection, indent=2)}')
return collection, {'Content-Type': as2.CONTENT_TYPE}