[feat] metrics: support for open metrics

searx/openmetrics.py

@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+"""Module providing support for displaying data in OpenMetrics format"""
+
+
+class OpenMetricsFamily:  # pylint: disable=too-few-public-methods
+    """A family of metrics.
+    The key parameter is the metric name that should be used (snake case).
+    The type_hint parameter must be one of 'counter', 'gauge', 'histogram', 'summary'.
+    The help_hint parameter is a short string explaining the metric.
+    The data_info parameter is a dictionary of descriptionary parameters for the data point (e.g. request method/path).
+    The data parameter is a flat list of the actual data in shape of a primive type.
+
+    See https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md for more information.
+    """
+
+    def __init__(self, key: str, type_hint: str, help_hint: str, data_info: list, data: list):
+        self.key = key
+        self.type_hint = type_hint
+        self.help_hint = help_hint
+        self.data_info = data_info
+        self.data = data
+
+    def __str__(self):
+        text_representation = f"""# HELP {self.key} {self.help_hint}
+# TYPE {self.key} {self.type_hint}
+"""
+
+        for i, data_info_dict in enumerate(self.data_info):
+            if not data_info_dict and data_info_dict != 0:
+                continue
+
+            info_representation = ','.join([f"{key}=\"{value}\"" for (key, value) in data_info_dict.items()])
+            text_representation += f"{self.key}{{{info_representation}}} {self.data[i]}\n"
+
+        return text_representation