Alerting: Support simplified routing receivers in Prometheus conversion API (#105135)

Adds ability to set notifications settings using the Prometheus conversion API.

The API now supports a new optional header: X-Grafana-Alerting-Notification-Settings which can be used to specify notification settings.

The value of the header is the AlertRuleNotificationSettings structure in JSON:
mimirtool rules load alerts.yaml --extra-headers 'X-Grafana-Alerting-Notification-Settings: {"receiver": "my-webhook", "group_by": ["cluster", "pod"]}'

pkg/services/ngalert/api/tooling/api.json

@@ -314,6 +314,16 @@
   },
   "AlertRuleNotificationSettings": {
    "properties": {
+    "active_time_intervals": {
+     "description": "Override the times when notifications should not be muted. These must match the name of a mute time interval defined\nin the alertmanager configuration time_intervals section. All notifications will be suppressed unless they are sent\nat the time that matches any interval.",
+     "example": [
+      "maintenance"
+     ],
+     "items": {
+      "type": "string"
+     },
+     "type": "array"
+    },
     "group_by": {
      "default": [
       "alertname",
@@ -341,7 +351,7 @@
      "type": "string"
     },
     "mute_time_intervals": {
-     "description": "Override the times when notifications should be muted. These must match the name of a mute time interval defined\nin the alertmanager configuration mute_time_intervals section. When muted it will not send any notifications, but\notherwise acts normally.",
+     "description": "Override the times when notifications should be muted. These must match the name of a mute time interval defined\nin the alertmanager configuration time_intervals section. When muted it will not send any notifications, but\notherwise acts normally.",
      "example": [
       "maintenance"
      ],
@@ -368,6 +378,12 @@
   },
   "AlertRuleNotificationSettingsExport": {
    "properties": {
+    "active_time_intervals": {
+     "items": {
+      "type": "string"
+     },
+     "type": "array"
+    },
     "group_by": {
      "items": {
       "type": "string"
@@ -2325,6 +2341,12 @@
   },
   "NotificationPolicyExport": {
    "properties": {
+    "active_time_intervals": {
+     "items": {
+      "type": "string"
+     },
+     "type": "array"
+    },
     "continue": {
      "type": "boolean"
     },
@@ -3710,6 +3732,12 @@
   "RouteExport": {
    "description": "RouteExport is the provisioned file export of definitions.Route. This is needed to hide fields that aren't useable in\nprovisioning file format. An alternative would be to define a custom MarshalJSON and MarshalYAML that excludes them.",
    "properties": {
+    "active_time_intervals": {
+     "items": {
+      "type": "string"
+     },
+     "type": "array"
+    },
     "continue": {
      "type": "boolean"
     },
@@ -4889,7 +4917,6 @@
    "type": "object"
   },
   "alertGroups": {
-   "description": "AlertGroups alert groups",
    "items": {
     "$ref": "#/definitions/alertGroup",
     "type": "object"
@@ -5176,7 +5203,6 @@
    "type": "object"
   },
   "gettableSilences": {
-   "description": "GettableSilences gettable silences",
    "items": {
     "$ref": "#/definitions/gettableSilence",
     "type": "object"
@@ -6661,4 +6687,4 @@
   }
  },
  "swagger": "2.0"
-}
+}