add legend format

public/app/plugins/datasource/cloudwatch/datasource.js

@@ -234,12 +234,7 @@ function (angular, _, kbn) {
         query.region = templateSrv.replace(target.region, options.scopedVars);
         query.namespace = templateSrv.replace(target.namespace, options.scopedVars);
         query.metricName = templateSrv.replace(target.metricName, options.scopedVars);
-        query.dimensions = _.map(_.keys(target.dimensions), function(key) {
-          return {
-            Name: templateSrv.replace(key, options.scopedVars),
-            Value: templateSrv.replace(target.dimensions[key], options.scopedVars)
-          };
-        });
+        query.dimensions = convertDimensionFormat(target.dimensions);
         query.statistics = getActivatedStatistics(target.statistics);
         query.period = parseInt(target.period, 10);
 
@@ -332,12 +327,7 @@ function (angular, _, kbn) {
         MetricName: metricName
       };
       if (!_.isEmpty(dimensions)) {
-        params.Dimensions = _.map(_.keys(dimensions), function(key) {
-          return {
-            Name: templateSrv.replace(key),
-            Value: templateSrv.replace(dimensions[key])
-          };
-        });
+        params.Dimensions = convertDimensionFormat(dimensions);
       }
 
       var d = $q.defer();
@@ -508,7 +498,27 @@ function (angular, _, kbn) {
 
       var dimensionPart = templateSrv.replace(JSON.stringify(options.dimensions));
       _.each(getActivatedStatistics(options.statistics), function(s) {
-        var metricLabel = md.Label + '_' + s + dimensionPart;
+        var originalSettings = _.templateSettings;
+        _.templateSettings = {
+          interpolate: /\{\{(.+?)\}\}/g
+        };
+        var template = _.template(options.legendFormat);
+
+        var metricLabel;
+        if (_.isEmpty(options.legendFormat)) {
+          metricLabel = md.Label + '_' + s + dimensionPart;
+        } else {
+          var d = convertDimensionFormat(options.dimensions);
+          metricLabel = template({
+            Region: templateSrv.replace(options.region),
+            Namespace: templateSrv.replace(options.namespace),
+            MetricName: templateSrv.replace(options.metricName),
+            Dimensions: d,
+            Statistics: s
+          });
+        }
+
+        _.templateSettings = originalSettings;
 
         var dps = _.map(md.Datapoints, function(value) {
           return [value[s], new Date(value.Timestamp).getTime()];
@@ -535,6 +545,15 @@ function (angular, _, kbn) {
       return Math.round(kbn.parseDate(date).getTime() / 1000);
     }
 
+    function convertDimensionFormat(dimensions) {
+      return _.map(_.keys(dimensions), function(key) {
+        return {
+          Name: templateSrv.replace(key),
+          Value: templateSrv.replace(dimensions[key])
+        };
+      });
+    }
+
     return CloudWatchDatasource;
   });
 

public/app/plugins/datasource/cloudwatch/partials/query.editor.html

@@ -207,5 +207,29 @@
       <div class="clearfix"></div>
     </div>
 
+    <div class="tight-form">
+      <ul class="tight-form-list" role="menu">
+        <li class="tight-form-item">
+          <i class="fa fa-eye invisible"></i>
+        </li>
+
+        <li class="tight-form-item">
+          Legend Format
+        </li>
+        <li>
+          <input type="text"
+                 class="input-xxlarge tight-form-input"
+                 ng-model="target.legendFormat"
+                 spellcheck='false'
+                 placeholder="legend format"
+                 data-min-length=0 data-items=100
+                 ng-change="refreshMetricData()"
+                 >
+        </li>
+      </ul>
+
+      <div class="clearfix"></div>
+    </div>
+
   </div>
 </div>