[#1] Count errors in log file

amarillo/plugins/metrics/metrics.py

@@ -62,6 +62,23 @@ def amarillo_grfs_file_size() -> Callable[[Info], None]:
 
     return instrumentation
 
+def amarillo_errors() -> Callable[[Info], None]:
+    METRIC = Gauge("amarillo_errors", "Number of errors in the error.log file")
+
+    def instrumentation(info: Info) -> None:
+        file_path = "error.log"
+        search_string = " - ERROR - "
+
+        error_count = 0
+        try:
+            with open(file_path, 'r') as file:
+                error_count = sum(1 for line in file if search_string in line)
+                # logger.info(f"Number of lines containing '{search_string}': {error_count}")
+        except FileNotFoundError:
+            logger.warning(f"File '{file_path}' not found.")
+        METRIC.set(error_count)
+
+    return instrumentation
 
 router = APIRouter(
     prefix="/metrics",
@@ -93,6 +110,7 @@ def setup(app: FastAPI):
     instrumentator.add(amarillo_trips_number_total())
     instrumentator.add(amarillo_gtfs_file_size())
     instrumentator.add(amarillo_grfs_file_size())
+    instrumentator.add(amarillo_errors())
 
 
     instrumentator.instrument(app)