[mongo] Add warnings when agent user is not authorized to run collSta…

…ts and indexStats on collections (#18506)

* raise unauthorized exception when running collStats

* log different error with unauthorized op

* more error handling

* add changelog

mongo/changelog.d/18506.added

@@ -0,0 +1 @@
+Add warning logs when agent user is not authorized to run $collStats and $indexStats on collections.

mongo/datadog_checks/mongo/collectors/coll_stats.py

@@ -44,11 +44,14 @@ def _get_collection_stats(self, api, coll_name):
         try:
             return api.coll_stats(self.db_name, coll_name)
         except OperationFailure as e:
+            if e.code == 13:
+                # Unauthorized to run $collStats, do not try use the compatible mode, raise the exception
+                raise e
             # Failed to get collection stats using $collStats aggregation
             self.log.debug(
                 "Failed not collect stats for collection %s with $collStats, fallback to collStats command",
                 coll_name,
-                e,
+                e.details,
             )
             self.coll_stats_pipeline_supported = False
             return [api.coll_stats_compatable(self.db_name, coll_name)]
@@ -61,7 +64,15 @@ def collect(self, api):
                 collection_stats = self._get_collection_stats(api, coll_name)
             except OperationFailure as e:
                 # Atlas restricts $collStats on system collections
-                self.log.warning("Could not collect stats for collection %s: %s", coll_name, e)
+                if e.code == 13:
+                    self.log.warning("Unauthorized to run $collStats on collection %s.%s", self.db_name, coll_name)
+                else:
+                    self.log.warning(
+                        "Could not collect stats for collection %s.%s: %s", self.db_name, coll_name, e.details
+                    )
+                continue
+            except Exception as e:
+                self.log.error("Unexpected error when fetch stats for collection %s.%s: %s", self.db_name, coll_name, e)
                 continue
 
             for coll_stats in collection_stats:

mongo/datadog_checks/mongo/collectors/index_stats.py

@@ -41,7 +41,14 @@ def collect(self, api):
                     self._submit_payload({"indexes": stats}, additional_tags, INDEX_METRICS, "collection")
             except OperationFailure as e:
                 # Atlas restricts $indexStats on system collections
-                self.log.warning("Could not collect index stats for collection %s: %s", coll_name, e)
+                if e.code == 13:
+                    self.log.warning("Unauthorized to run $indexStats on collection %s.%s", self.db_name, coll_name)
+                else:
+                    self.log.warning(
+                        "Could not collect index stats for collection %s.%s: %s", self.db_name, coll_name, e.details
+                    )
             except Exception as e:
-                self.log.error("Could not fetch indexes stats for collection %s: %s", coll_name, e)
+                self.log.error(
+                    "Unexpected error when fetch indexes stats for collection %s.%s: %s", self.db_name, coll_name, e
+                )
                 raise e