bug: Add additional logging around APNS HTTP2 connectivity

Issue #1393 notes, sending push messages across APNS seems to work
great after a deploy, but then degrades after a week or so. #1394 is
a possible work-around (by double-pooling connections and using a
dedicated connection terminator), but it's messy and hacky.

What's really needed is a bit more visibility into what may be
happening, and that will involve logging all APNS communication
exceptions reliably.

Issue #1393

autopush/router/apnsrouter.py

@@ -147,29 +147,32 @@ def _route(self, notification, router_data):
         apns_id = str(uuid.uuid4()).lower()
         # APNs may force close a connection on us without warning.
         # if that happens, retry the message.
-        success = False
         try:
             apns_client.send(router_token=router_token, payload=payload,
                              apns_id=apns_id)
-            success = True
-        except ConnectionError:
-            self.metrics.increment("notification.bridge.connection.error",
-                                   tags=make_tags(
-                                       self._base_tags,
-                                       application=rel_channel,
-                                       reason="connection_error"))
-        except (HTTP20Error, socket.error):
+        except Exception as e:
+            # We sometimes see strange errors around sending push notifications
+            # to APNS. We get reports that after a new deployment things work,
+            # but then after a week or so, messages across the APNS bridge
+            # start to fail. The connections appear to be working correctly,
+            # so we don't think that this is a problem related to how we're
+            # connecting.
+            if isinstance(e, ConnectionError):
+                reason = "connection_error"
+            elif isinstance(e, (HTTP20Error, socket.error)):
+                reason = "http2_error"
+            else:
+                reason = "unknown"
             self.metrics.increment("notification.bridge.connection.error",
                                    tags=make_tags(self._base_tags,
                                                   application=rel_channel,
-                                                  reason="http2_error"))
-        if not success:
+                                                  reason=reason))
             raise RouterException(
-                "Server error",
+                "APNS Router Error: {}".format(str(e)),
                 status_code=502,
                 response_body="APNS returned an error processing request",
-                log_exception=False,
             )
+
         location = "%s/m/%s" % (self.conf.endpoint_url, notification.version)
         self.metrics.increment("notification.bridge.sent",
                                tags=make_tags(self._base_tags,