Add auth_providers

docs/reference/http.rst

@@ -171,6 +171,9 @@ Auth Extension
 ``auth_ui_renders_total``
   **Counter.** Number of UI pages rendered by the Auth extension.
 
+``auth_providers``
+  **Histogram.** Number of Auth providers configured.
+
 Errors
 ^^^^^^
 

edb/server/dbview/dbview.pxd

@@ -98,6 +98,7 @@ cdef class Database:
     cdef _cache_compiled_query(self, key, query_unit)
     cdef _new_view(self, query_cache, protocol_version)
     cdef _remove_view(self, view)
+    cdef _observe_auth_ext_config(self)
     cdef _update_backend_ids(self, new_types)
     cdef _set_and_signal_new_user_schema(
         self,

edb/server/dbview/dbview.pyx

@@ -184,6 +184,7 @@ cdef class Database:
         self.reflection_cache = reflection_cache
         self.backend_ids = backend_ids
         self.extensions = extensions
+        self._observe_auth_ext_config()
 
     @property
     def server(self):
@@ -220,8 +221,27 @@ cdef class Database:
             self.reflection_cache = reflection_cache
         if db_config is not None:
             self.db_config = db_config
+            self._observe_auth_ext_config()
         self._invalidate_caches()
 
+    cdef _observe_auth_ext_config(self):
+        key = "ext::auth::AuthConfig::providers"
+        if (
+            self.db_config is not None and
+            self.user_config_spec is not None and
+            key in self.user_config_spec
+        ):
+            providers = config.lookup(
+                key,
+                self.db_config,
+                spec=self.user_config_spec,
+            )
+            metrics.auth_providers.set(
+                len(providers),
+                self.tenant.get_instance_name(),
+                self.name,
+            )
+
     cdef _update_backend_ids(self, new_types):
         self.backend_ids.update(new_types)
 

edb/server/metrics.py

@@ -187,3 +187,9 @@
     "Number of UI pages rendered by the Auth extension.",
     labels=("tenant",),
 )
+
+auth_providers = registry.new_labeled_gauge(
+    'auth_providers',
+    'Number of Auth providers configured.',
+    labels=('tenant', 'database'),
+)