followers_synchronization endpoint

daemon.py

@@ -119,6 +119,7 @@ from inbox import run_inbox_queue_watchdog
 from inbox import save_post_to_inbox_queue
 from inbox import populate_replies
 from inbox import receive_edit_to_post
+from follow import get_followers_for_domain
 from follow import follower_approval_active
 from follow import is_following_actor
 from follow import get_following_feed
@@ -876,6 +877,7 @@ class PubServer(BaseHTTPRequestHandler):
     def _secure_mode(self, curr_session, proxy_type: str,
                      force: bool = False) -> bool:
         """http authentication of GET requests for json
+        aka authorized fetch
         """
         if not self.server.secure_mode and not force:
             return True
@@ -16901,11 +16903,63 @@ class PubServer(BaseHTTPRequestHandler):
                             '_GET', '_security_txt[calling_domain]',
                             self.server.debug)
 
+        # followers synchronization
         if self.path.startswith('/users/') and \
            self.path.endswith('/followers_synchronization'):
-            print('DEBUG: followers synchronization request ' +
-                  self.path + ' ' + calling_domain)
+            if self.server.followers_synchronization:
+                # only do one request at a time
+                self._503()
+                return
+            self.server.followers_synchronization = True
+            if self.server.debug:
+                print('DEBUG: followers synchronization request ' +
+                      self.path + ' ' + calling_domain)
+            # check authorized fetch
+            if self._secure_mode(curr_session, proxy_type):
+                nickname = get_nickname_from_actor(self.path)
+                sync_list = \
+                    get_followers_for_domain(self.server.base_dir,
+                                             nickname, self.server.domain,
+                                             calling_domain)
+                id_str = self.server.http_prefix + '://' + \
+                    self.server.domain_full + \
+                    self.path.replace('/followers_synchronization',
+                                      '/followers?domain=' + calling_domain)
+                sync_json = {
+                    '@context': 'https://www.w3.org/ns/activitystreams',
+                    'id': id_str,
+                    'orderedItems': sync_list,
+                    'type': 'OrderedCollection'
+                }
+                msg_str = json.dumps(sync_json, ensure_ascii=False)
+                msg_str = self._convert_domains(calling_domain, referer_domain,
+                                                msg_str)
+                msg = msg_str.encode('utf-8')
+                msglen = len(msg)
+                self._set_headers('application/json', msglen,
+                                  None, calling_domain, False)
+                self._write(msg)
+                self.server.followers_synchronization = False
+                return
+            else:
+                # request was not signed
+                result_json = {
+                    "error": "Request not signed"
+                }
+                msg_str = json.dumps(result_json, ensure_ascii=False)
+                msg = msg_str.encode('utf-8')
+                msglen = len(msg)
+                accept_str = self.headers['Accept']
+                if 'json' in accept_str:
+                    protocol_str = \
+                        get_json_content_from_accept(accept_str)
+                    self._set_headers(protocol_str, msglen,
+                                      None, calling_domain, False)
+                    self._write(msg)
+                    self.server.followers_synchronization = False
+                    return
             self._404()
+            self.server.followers_synchronization = False
             return
 
         if self.path == '/logout':
@@ -23333,6 +23387,9 @@ def run_daemon(max_hashtags: int,
     # scan the theme directory for any svg files containing scripts
     assert not scan_themes_for_scripts(base_dir)
 
+    # lock for followers synchronization
+    httpd.followers_synchronization = False
+
     # permitted sites from which the buy button may be displayed
     httpd.buy_sites = load_buy_sites(base_dir)
 

follow.py

@@ -9,6 +9,7 @@ __module_group__ = "ActivityPub"
 
 from pprint import pprint
 import os
+from utils import get_user_paths
 from utils import acct_handle_dir
 from utils import has_object_string_object
 from utils import has_object_string_type
@@ -1360,6 +1361,50 @@ def deny_follow_request_via_server(session,
     return deny_html
 
 
+def get_followers_for_domain(base_dir: str,
+                             nickname: str, domain: str,
+                             search_domain: str) -> []:
+    """Returns the followers for a given domain
+    this is used for followers synchronization
+    """
+    followers_filename = \
+        acct_dir(base_dir, nickname, domain) + '/followers.txt'
+    if not os.path.isfile(followers_filename):
+        return []
+    lines = []
+    try:
+        with open(followers_filename, 'r', encoding='utf-8') as fp_foll:
+            lines = fp_foll.read().splitlines()
+    except OSError:
+        print('EX: get_followers_for_domain unable to read followers ' +
+              followers_filename)
+    result = []
+    for line_str in lines:
+        if search_domain not in line_str:
+            continue
+        if line_str.endswith('@' + search_domain):
+            nick = line_str.split('@')[0]
+            paths_list = get_user_paths()
+            found = False
+            for prefix in ('https', 'http'):
+                if found:
+                    break
+                for possible_path in paths_list:
+                    url = prefix + '://' + search_domain + \
+                        possible_path + nick
+                    filename = base_dir + '/cache/actors/' + \
+                        url.replace('/', '#') + '.json'
+                    if not os.path.isfile(filename):
+                        continue
+                    if url not in result:
+                        result.append(url)
+                    found = True
+                    break
+        elif '://' + search_domain in line_str:
+            result.append(line_str)
+    return result
+
+
 def get_followers_of_actor(base_dir: str, actor: str, debug: bool) -> {}:
     """In a shared inbox if we receive a post we know who it's from
     and if it's addressed to followers then we need to get a list of those.