feat: add support of openmetrics (#144)

* feat: add openmetrics support & endpoint

* add support of named resources

* update docstrings

* generate docs

* add another test for http api

src/ahriman/web/views/base.py

@@ -167,6 +167,9 @@ class BaseView(View, CorsViewMixin):
         """
         HEAD method implementation based on the result of GET method
 
+        Returns:
+            StreamResponse: generated response for the request
+
         Raises:
             HTTPMethodNotAllowed: in case if there is no GET method implemented
         """

src/ahriman/web/views/v1/packages/packages.py

@@ -46,7 +46,7 @@ class PackagesView(StatusViewGuard, BaseView):
     ROUTES = ["/api/v1/packages"]
 
     @apidocs(
-        tags=["packages"],
+        tags=["Packages"],
         summary="Get packages list",
         description="Retrieve packages and their descriptors",
         permission=GET_PERMISSION,

src/ahriman/web/views/v1/status/metrics.py

@@ -0,0 +1,56 @@
+#
+# Copyright (c) 2021-2025 ahriman team.
+#
+# This file is part of ahriman
+# (see https://github.com/arcan1s/ahriman).
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+from aiohttp.web import Response
+from typing import ClassVar
+
+from ahriman.models.user_access import UserAccess
+from ahriman.web.apispec.decorators import apidocs
+from ahriman.web.middlewares.metrics_handler import metrics
+from ahriman.web.schemas import AnySchema
+from ahriman.web.views.base import BaseView
+
+
+class MetricsView(BaseView):
+    """
+    open metrics endpoints
+
+    Attributes:
+        GET_PERMISSION(UserAccess): (class attribute) get permissions of self
+    """
+
+    GET_PERMISSION: ClassVar[UserAccess] = UserAccess.Unauthorized
+    ROUTES = ["/api/v1/metrics"]
+
+    @apidocs(
+        tags=["Status"],
+        summary="OpenMetrics endpoint",
+        description="Get service metrics in OpenMetrics format",
+        permission=GET_PERMISSION,
+        error_404_description="Endpoint is disabled",
+        schema=AnySchema,
+    )
+    async def get(self) -> Response:
+        """
+        get service HTTP metrics
+
+        Returns:
+            Response: 200 with service metrics as generated by the library
+        """
+        return await metrics(self.request)