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scrape recent statuses for mentions of other instances

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This commit is contained in:
Tao Bojlen 2018-09-03 00:04:03 +02:00
parent d383bca0d8
commit a176e35ec2
6 changed files with 98 additions and 24 deletions
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3
apiv1/views.py
View file

@ -1,5 +1,4 @@
from rest_framework import viewsets
from django.db.models import Prefetch
from scraper.models import Instance, PeerRelationship
from apiv1.serializers import InstanceListSerializer, InstanceDetailSerializer, NodeSerializer, EdgeSerializer
@ -25,7 +24,7 @@ class EdgeView(viewsets.ReadOnlyModelViewSet):
"""
Endpoint to get a list of the graph's edges in a SigmaJS-friendly format.
"""
queryset = PeerRelationship.objects.all()[:1000]
queryset = PeerRelationship.objects.filter(source__status='success', target__status='success')
serializer_class = EdgeSerializer

9
requirements.txt
View file

@ -1,19 +1,26 @@
autopep8==1.3.5
certifi==2018.8.24
chardet==3.0.4
dill==0.2.5
Django==2.1
django-bulk-update==2.2.0
django-cors-headers==2.4.0
django-letsencrypt==3.0.1
django-silk==3.0.1
djangorestframework==3.8.2
future==0.16.0
gprof2dot==2016.10.13
idna==2.7
Jinja2==2.10
MarkupSafe==1.0
psycopg2-binary==2.7.5
pycodestyle==2.4.0
PyFunctional==1.1.3
Pygments==2.2.0
python-dateutil==2.7.3
pytz==2018.5
requests==2.19.1
six==1.11.0
six==1.10.0
sqlparse==0.2.4
tabulate==0.7.7
urllib3==1.23

2
scraper/management/commands/_util.py
View file

@ -53,7 +53,7 @@ def get_key(data, keys: list):
while keys:
val = val[keys.pop(0)]
return val
except KeyError:
except (KeyError, TypeError):
return ''

98
scraper/management/commands/scrape.py
View file

@ -7,7 +7,10 @@ import json
import multiprocessing as mp
import requests
import time
from datetime import datetime, timedelta
from dateutil.parser import parse as datetime_parser
from datetime import datetime, timedelta, timezone
from functional import seq
from django_bulk_update.helper import bulk_update
from django.core.management.base import BaseCommand
from django import db
from scraper.models import Instance, PeerRelationship
@ -28,7 +31,7 @@ from scraper.management.commands._util import require_lock, InvalidResponseError
SEED = 'mastodon.social'
TIMEOUT = 10
NUM_THREADS = 4
NUM_THREADS = 64
class Command(BaseCommand):
@ -36,16 +39,17 @@ class Command(BaseCommand):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.done_bag = set()
self.scraped_ids = set()
@staticmethod
def get_instance_info(instance_name: str):
"""Collect info about instance"""
url = 'https://' + instance_name + '/api/v1/instance'
response = requests.get(url, timeout=TIMEOUT)
if response.status_code != 200:
json = response.json()
if response.status_code != 200 or get_key(json, ['error']):
raise InvalidResponseError("Could not get info for {}".format(instance_name))
return response.json()
return json
@staticmethod
def get_instance_peers(instance_name: str):
@ -54,10 +58,52 @@ class Command(BaseCommand):
# (https://github.com/tootsuite/mastodon/pull/6125)
url = 'https://' + instance_name + '/api/v1/instance/peers'
response = requests.get(url, timeout=TIMEOUT)
json = response.json()
if response.status_code != 200 or not isinstance(json, list):
peers = response.json()
if response.status_code != 200 or not isinstance(peers, list) or get_key(peers, ['error']):
raise InvalidResponseError("Could not get peers for {}".format(instance_name))
return json
# Get rid of peers that just say "null" and the instance itself
return [peer for peer in peers if peer and peer != instance_name]
@staticmethod
def get_statuses(instance_name: str):
"""Collect all statuses that mention users on other instances"""
mentions = []
datetime_threshold = datetime.now(timezone.utc) - timedelta(weeks=1)
statuses_seen = 0
# We'll ask for 1000 statuses, but Mastodon never returns more than 40. Some Pleroma instances will ignore
# the limit and return 20.
url = 'https://' + instance_name + '/api/v1/timelines/public?local=true&limit=1000'
while True:
response = requests.get(url, timeout=TIMEOUT)
statuses = response.json()
if response.status_code != 200 or get_key(statuses, ['error']):
raise InvalidResponseError("Could not get statuses for {}".format(instance_name))
elif len(statuses) == 0:
break
# Get mentions from this instance
mentions.extend((seq(statuses)
.filter(lambda s: datetime_parser(s['created_at']) > datetime_threshold)
.flat_map(lambda s: s['mentions']))) # map to mentions
# Find out if we should stop here
earliest_status = statuses[-1]
earliest_time_seen = datetime_parser(earliest_status['created_at'])
statuses_seen += len(statuses)
# Mastodon returns max 40 statuses; if we ever see less than that we know there aren't any more
if earliest_time_seen < datetime_threshold or statuses_seen >= 2000:
break
# Continuing, so get url for next page
min_id = earliest_status['id']
url = 'https://' + instance_name + '/api/v1/timelines/public?local=true&limit=1000&max_id=' + min_id
mentions_seq = (seq(mentions)
.filter(lambda m: not m['acct'].endswith(instance_name) and '@' in m['acct'])
.map(lambda m: m['acct'].split('@')[-1]) # map to instance name
.map(lambda m: (m, 1))
.reduce_by_key(lambda x, y: x+y)) # sequence of tuples (instance, count)
mentions_by_instance = {t[0]: t[1] for t in mentions_seq} # dict of instance -> number of mentions
return mentions_by_instance, statuses_seen
def process_instance(self, instance: Instance):
"""Given an instance, get all the data we're interested in"""
@ -65,11 +111,11 @@ class Command(BaseCommand):
try:
data['instance_name'] = instance.name
data['info'] = self.get_instance_info(instance.name)
# Get rid of peers that just say "null" and the instance itself
data['peers'] = [peer for peer in self.get_instance_peers(instance.name) if peer and peer != instance.name]
data['peers'] = self.get_instance_peers(instance.name)
if not data['info'] and not data['peers']:
# We got a response from the instance, but it didn't have any of the information we were expecting.
raise InvalidResponseError
data['mentions'], data['statuses_seen'] = self.get_statuses(instance.name)
data['status'] = 'success'
return data
except (InvalidResponseError,
@ -98,9 +144,7 @@ class Command(BaseCommand):
# bulk_create doesn't call save(), so the auto_now_add field won't get set automatically
new_instances = [Instance(name=id, first_seen=datetime.now(), last_updated=datetime.now())
for id in new_instance_ids]
print("Before: {}".format(len(existing_instance_ids)))
existing_instance_ids.extend(new_instance_ids)
print("After: {}".format(len(existing_instance_ids)))
Instance.objects.bulk_create(new_instances)
for new_instance in new_instances:
queue.put(new_instance)
@ -113,6 +157,18 @@ class Command(BaseCommand):
new_relationships = [PeerRelationship(source=instance, target_id=new_peer, first_seen=datetime.now())
for new_peer in new_peer_ids]
PeerRelationship.objects.bulk_create(new_relationships)
if data['status'] == 'success' and data['mentions']:
# At this point, we can assume that a relationship exists for every peer that's mentioned in statuses
mentions = data['mentions']
relationships = PeerRelationship.objects.filter(source=instance,
target_id__in=list(mentions.keys()))
for relationship in relationships:
relationship.mention_count = mentions[relationship.target_id]
relationship.statuses_seen = data['statuses_seen']
relationship.last_updated = datetime.now()
bulk_update(relationships, update_fields=['mention_count', 'statuses_seen', 'last_updated'])
self.stdout.write(log("Saved {}".format(data['instance_name'])))
def worker(self, queue: mp.JoinableQueue, existing_instance_ids):
@ -121,33 +177,37 @@ class Command(BaseCommand):
db.connections.close_all()
while True:
instance = queue.get()
if instance in self.done_bag:
self.stderr.write(log("Skipping {}, already done. This should not have been added to the queue!".format(instance)))
if instance.name in self.scraped_ids:
self.stderr.write(log("Skipping {}, already done. This should not have been added to the queue!"
.format(instance)))
queue.task_done()
else:
# Fetch data on instance
self.stdout.write(log("Processing {}".format(instance.name)))
data = self.process_instance(instance)
self.save_data(instance, data, queue, existing_instance_ids)
self.done_bag.add(instance)
self.scraped_ids.add(instance.name)
queue.task_done()
def handle(self, *args, **options):
start_time = time.time()
stale_instances = Instance.objects.filter(last_updated__lte=datetime.now()-timedelta(weeks=1))
stale_instances = Instance.objects.filter(last_updated__lte=datetime.now()-timedelta(days=1))
with mp.Manager() as manager:
# Share the list of existing instances amongst all threads (to avoid each thread having to query
# for it on every instance it scrapes)
existing_instance_ids = manager.list(list(Instance.objects.values_list('name', flat=True)))
queue = mp.JoinableQueue()
if stale_instances:
queue.put(list(stale_instances))
for instance in stale_instances:
queue.put(instance)
elif not Instance.objects.exists():
instance, _ = Instance.objects.get_or_create(name=SEED)
queue.put(instance)
existing_instance_ids.append(instance.name)
queue.put(instance)
pool = mp.Pool(NUM_THREADS, initializer=self.worker, initargs=(queue, existing_instance_ids))
queue.join()
end_time = time.time()
self.stdout.write(self.style.SUCCESS(log("Successfully scraped the fediverse in {:.0f}s".format(end_time-start_time))))
self.stdout.write(self.style.SUCCESS(log("Scraped {} instances in {:.0f}s"
.format(len(self.scraped_ids), end_time - start_time))))

5
scraper/migrations/0001_initial.py
View file

@ -1,4 +1,4 @@
# Generated by Django 2.1 on 2018-09-01 14:00
# Generated by Django 2.1 on 2018-09-01 22:28
from django.db import migrations, models
import django.db.models.deletion
@ -30,7 +30,10 @@ class Migration(migrations.Migration):
name='PeerRelationship',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('mention_count', models.IntegerField(blank=True, null=True)),
('statuses_seen', models.IntegerField(blank=True, null=True)),
('first_seen', models.DateTimeField(auto_now_add=True)),
('last_updated', models.DateTimeField(auto_now=True)),
('source', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='following_relationship', to='scraper.Instance')),
('target', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='follower_relationships', to='scraper.Instance')),
],

5
scraper/models.py
View file

@ -31,5 +31,10 @@ class PeerRelationship(models.Model):
source = models.ForeignKey(Instance, related_name="following_relationship", on_delete=models.CASCADE)
target = models.ForeignKey(Instance, related_name="follower_relationships", on_delete=models.CASCADE)
# Interaction stats
mention_count = models.IntegerField(blank=True, null=True)
statuses_seen = models.IntegerField(blank=True, null=True) # in case we want mention_count as a ratio
# Metadata
first_seen = models.DateTimeField(auto_now_add=True)
last_updated = models.DateTimeField(auto_now=True)