kata-monitor: export get stats for sandbox

Gathering stats for a given sandbox is pretty useful; let's export a
function from katamonitor pkg to do this.

Signed-off-by: Eric Ernst <eric_ernst@apple.com>
(cherry picked from commit 3787306)

src/runtime/pkg/kata-monitor/metrics.go

@@ -176,7 +176,7 @@ func (km *KataMonitor) aggregateSandboxMetrics(encoder expfmt.Encoder) error {
 	for sandboxID, namespace := range sandboxes {
 		wg.Add(1)
 		go func(sandboxID, namespace string, results chan<- []*dto.MetricFamily) {
-			sandboxMetrics, err := getSandboxMetrics(sandboxID)
+			sandboxMetrics, err := getParsedMetrics(sandboxID)
 			if err != nil {
 				monitorLog.WithError(err).WithField("sandbox_id", sandboxID).Errorf("failed to get metrics for sandbox")
 			}
@@ -229,12 +229,11 @@ func (km *KataMonitor) aggregateSandboxMetrics(encoder expfmt.Encoder) error {
 			return err
 		}
 	}
-
 	return nil
+
 }
 
-// getSandboxMetrics will get sandbox's metrics from shim
-func getSandboxMetrics(sandboxID string) ([]*dto.MetricFamily, error) {
+func getParsedMetrics(sandboxID string) ([]*dto.MetricFamily, error) {
 	body, err := doGet(sandboxID, defaultTimeout, "metrics")
 	if err != nil {
 		return nil, err
@@ -243,6 +242,16 @@ func getSandboxMetrics(sandboxID string) ([]*dto.MetricFamily, error) {
 	return parsePrometheusMetrics(sandboxID, body)
 }
 
+// GetSandboxMetrics will get sandbox's metrics from shim
+func GetSandboxMetrics(sandboxID string) (string, error) {
+	body, err := doGet(sandboxID, defaultTimeout, "metrics")
+	if err != nil {
+		return "", err
+	}
+
+	return string(body), nil
+}
+
 // parsePrometheusMetrics will decode metrics from Prometheus text format
 // and return array of *dto.MetricFamily with an ASC order
 func parsePrometheusMetrics(sandboxID string, body []byte) ([]*dto.MetricFamily, error) {