Handle 410 gone for remote activities

little_boxes/activitypub.py

@@ -15,9 +15,11 @@ from .backend import Backend
 from .collection import parse_collection
 from .errors import BadActivityError
 from .errors import Error
+from .errors import RemoteActivityGoneError
 from .errors import NotFromOutboxError
 from .errors import UnexpectedActivityTypeError
 
+
 logger = logging.getLogger(__name__)
 
 UninitializedBackendError = Error("a backend must be initialized")
@@ -492,7 +494,12 @@ class BaseActivity(object, metaclass=_ActivityMeta):
                     continue
                 actor = recipient
             else:
-                raw_actor = BACKEND.fetch_iri(recipient)
+                try:
+                    raw_actor = BACKEND.fetch_iri(recipient)
+                except RemoteActivityGoneError:
+                    logger.info(f"{recipient} is gone")
+                    continue
+
                 if raw_actor["type"] == ActivityType.PERSON.value:
                     actor = Person(**raw_actor)
 
@@ -511,12 +518,19 @@ class BaseActivity(object, metaclass=_ActivityMeta):
                     ActivityType.ORDERED_COLLECTION.value,
                 ]:
                     for item in parse_collection(raw_actor, fetcher=BACKEND.fetch_iri):
+                        # XXX(tsileo): is nested collection support needed here?
                         if item in [actor_id, AS_PUBLIC]:
                             continue
                         try:
-                            col_actor = Person(**BACKEND.fetch_iri(item))
+                            col_actor = fetch_remote_activity(
+                                item, expected=ActivityType.PERSON
+                            )
                         except UnexpectedActivityTypeError:
                             logger.exception(f"failed to fetch actor {item!r}")
+                            continue
+                        except RemoteActivityGoneError:
+                            logger.info(f"{item} is gone")
+                            continue
 
                         if col_actor.endpoints:
                             shared_inbox = col_actor.endpoints.get("sharedInbox")
@@ -1056,7 +1070,9 @@ class Note(BaseActivity):
         )
 
 
-def fetch_remote_activity(iri: str, expected: Optional[ActivityType]) -> BaseActivity:
+def fetch_remote_activity(
+    iri: str, expected: Optional[ActivityType] = None
+) -> BaseActivity:
     return parse_activity(get_backend().fetch_iri(iri), expected=expected)
 
 

little_boxes/backend.py

@@ -7,6 +7,7 @@ import requests
 
 from .__version__ import __version__
 from .errors import ActivityNotFoundError
+from .errors import RemoteActivityGoneError
 from .urlutils import check_url
 
 if typing.TYPE_CHECKING:
@@ -31,6 +32,9 @@ class Backend(abc.ABC):
             headers={"User-Agent": self.user_agent(), "Accept": "application/json"},
             **kwargs,
         )
+
+        resp.raise_for_status()
+
         return resp
 
     def is_from_outbox(
@@ -60,6 +64,8 @@ class Backend(abc.ABC):
         )
         if resp.status_code == 404:
             raise ActivityNotFoundError(f"{iri} is not found")
+        elif resp.status_code == 410:
+            raise RemoteActivityGoneError(f"{iri} is gone")
 
         resp.raise_for_status()
 

little_boxes/errors.py

@@ -5,6 +5,14 @@ from typing import Optional
 
 
 class Error(Exception):
+    """Base error for exceptions raised by this package."""
+
+
+class RemoteActivityGoneError(Error):
+    """Raised when trying to fetch a remote activity that was deleted."""
+
+
+class ServerError(Error):
     """HTTP-friendly base error, with a status code, a message and an optional payload."""
 
     status_code = 400
@@ -36,21 +44,21 @@ class Error(Exception):
         return self.__repr__()
 
 
-class ActorBlockedError(Error):
+class ActorBlockedError(ServerError):
     """Raised when an activity from a blocked actor is received."""
 
 
-class NotFromOutboxError(Error):
+class NotFromOutboxError(ServerError):
     """Raised when an activity targets an object from the inbox when an object from the oubox was expected."""
 
 
-class ActivityNotFoundError(Error):
+class ActivityNotFoundError(ServerError):
     """Raised when an activity is not found."""
 
     status_code = 404
 
 
-class BadActivityError(Error):
+class BadActivityError(ServerError):
     """Raised when an activity could not be parsed/initialized."""