Update REST API responses to include Description, Unit, Dynamic, and

DynamicElements for metrics returned from the metric catalog. This
includes setting dynamic elements of the metric namespace when the
metric is dynamic.

mgmt/rest/metric.go

@@ -105,9 +105,18 @@ func (s *Server) getMetricsFromTree(w http.ResponseWriter, r *http.Request, para
 	}
 
 	b := &rbody.MetricReturned{}
+	dyn, indexes := mt.Namespace().IsDynamic()
+	var dynamicElements []rbody.DynamicElement
+	if dyn {
+		dynamicElements = getDynamicElements(mt.Namespace(), indexes)
+	}
 	mb := &rbody.Metric{
-		Namespace:               mt.Namespace().String(),
-		Version:                 mt.Version(),
+		Namespace:       mt.Namespace().String(),
+		Version:         mt.Version(),
+		Dynamic:         dyn,
+		DynamicElements: dynamicElements,
+		Description:     mt.Description(),
+		Unit:            mt.Unit(),
 		LastAdvertisedTimestamp: mt.LastAdvertisedTime().Unix(),
 		Href: catalogedMetricURI(r.Host, mt),
 	}
@@ -144,10 +153,19 @@ func respondWithMetrics(host string, mets []core.CatalogedMetric, w http.Respons
 				Maximum:  r.Maximum,
 			})
 		}
+		dyn, indexes := met.Namespace().IsDynamic()
+		var dynamicElements []rbody.DynamicElement
+		if dyn {
+			dynamicElements = getDynamicElements(met.Namespace(), indexes)
+		}
 		b = append(b, rbody.Metric{
 			Namespace:               met.Namespace().String(),
 			Version:                 met.Version(),
 			LastAdvertisedTimestamp: met.LastAdvertisedTime().Unix(),
+			Description:             met.Description(),
+			Dynamic:                 dyn,
+			DynamicElements:         dynamicElements,
+			Unit:                    met.Unit(),
 			Policy:                  policies,
 			Href:                    catalogedMetricURI(host, met),
 		})
@@ -159,3 +177,16 @@ func respondWithMetrics(host string, mets []core.CatalogedMetric, w http.Respons
 func catalogedMetricURI(host string, mt core.CatalogedMetric) string {
 	return fmt.Sprintf("%s://%s/v1/metrics%s?ver=%d", protocolPrefix, host, mt.Namespace().String(), mt.Version())
 }
+
+func getDynamicElements(ns core.Namespace, indexes []int) []rbody.DynamicElement {
+	elements := make([]rbody.DynamicElement, 0, len(indexes))
+	for _, v := range indexes {
+		e := ns.Element(v)
+		elements = append(elements, rbody.DynamicElement{
+			Index:       v,
+			Name:        e.Name,
+			Description: e.Description,
+		})
+	}
+	return elements
+}