lib/promscrape/discovery: properly apply the resource_group filter for Azure service discovery

Previously, this filter did not apply to virtual
machine scale sets, causing all virtual machines to be discovered.

 This commit conditionally adds `resource_group` filter for Azure service discovery on virtual
machine scale sets. 

 Related issue:
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7630.

docs/changelog/CHANGELOG.md

@@ -27,6 +27,7 @@ See also [LTS releases](https://docs.victoriametrics.com/lts-releases/).
 
 * BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent): Properly return `200 OK` HTTP status code when importing data via [Pushgateway protocol](https://docs.victoriametrics.com/#how-to-import-data-in-prometheus-exposition-format) using [multitenant URL format](https://docs.victoriametrics.com/cluster-victoriametrics/#url-format). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3636) and [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/7571).
 * BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent): Properly set `TCP` connection timeout for `Kubernetes API server` connection for metric scrapping with `kubernetes_sd_configs`. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7127).
+* BUGFIX: [vmagent](https://docs.victoriametrics.com/vmagent): fix the `resource_group` filter for Azure service discovery on virtual machine scale sets. Previously, this filter did not apply to virtual machine scale sets, causing all virtual machines to be discovered. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7630).
 * BUGFIX: [vmsingle](https://docs.victoriametrics.com/single-server-victoriametrics/), `vmselect` in [VictoriaMetrics cluster](https://docs.victoriametrics.com/cluster-victoriametrics/): properly return result for binary operation `^` aka pow at query requests for `NaN` values. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7359) for details.
 * BUGFIX: [vmui](https://docs.victoriametrics.com/#vmui): fix rendering of isolated data points on the graph that are not connected to other points.
 * BUGFIX: [vmalert](https://docs.victoriametrics.com/vmalert): improve the correctness of alert [state restoration](https://docs.victoriametrics.com/vmalert/#alerts-state-on-restarts). Previously, it could result in false-positive alerts if alert was resolved shortly before vmalert restart.

lib/promscrape/discovery/azure/machine.go

@@ -190,9 +190,16 @@ type scaleSet struct {
 }
 
 // See https://docs.microsoft.com/en-us/rest/api/compute/virtual-machine-scale-sets/list-all
+// and https://learn.microsoft.com/en-us/rest/api/compute/virtual-machine-scale-sets/list (need resourceGroup)
 func listScaleSetRefs(ac *apiConfig) ([]scaleSet, error) {
 	// https://management.azure.com/subscriptions/{subscriptionId}/providers/Microsoft.Compute/virtualMachineScaleSets?api-version=2022-03-01
-	apiURL := "/subscriptions/" + ac.subscriptionID + "/providers/Microsoft.Compute/virtualMachineScaleSets?api-version=2022-03-01"
+	apiURL := "/subscriptions/" + ac.subscriptionID
+	if ac.resourceGroup != "" {
+		// special case filter by resourceGroup
+		// https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.Compute/virtualMachineScaleSets?api-version=2022-03-01
+		apiURL += "/resourceGroups/" + ac.resourceGroup
+	}
+	apiURL += "/providers/Microsoft.Compute/virtualMachineScaleSets?api-version=2022-03-01"
 	var sss []scaleSet
 	err := visitAllAPIObjects(ac, apiURL, func(data json.RawMessage) error {
 		var ss scaleSet

lib/promscrape/discovery/azure/machine_test.go

@@ -93,6 +93,7 @@ func TestGetVirtualMachinesSuccess(t *testing.T) {
 				c:              c,
 				apiServerHost:  u.Hostname(),
 				subscriptionID: "some-id",
+				resourceGroup:  "some-resource-group",
 				refreshToken: func() (string, time.Duration, error) {
 					return "auth-token", 0, nil
 				},