Show relevant tag name suggestions for OpenTSDB, closes #3610

public/app/plugins/datasource/opentsdb/datasource.js

@@ -15,6 +15,7 @@ function (angular, _, dateMath) {
     this.withCredentials = instanceSettings.withCredentials;
     this.basicAuth = instanceSettings.basicAuth;
     this.supportMetrics = true;
+    this.tagKeys = {};
 
     // Called once per panel (graph)
     this.query = function(options) {
@@ -50,10 +51,13 @@ function (angular, _, dateMath) {
           if (index === -1) {
             index = 0;
           }
+
+          this._saveTagKeys(metricData);
+
           return transformMetricData(metricData, groupByTags, options.targets[index], options);
-        });
+        }.bind(this));
         return { data: result };
-      });
+      }.bind(this));
     };
 
     this.performTimeSeriesQuery = function(queries, start, end) {
@@ -87,6 +91,19 @@ function (angular, _, dateMath) {
       return backendSrv.datasourceRequest(options);
     };
 
+    this.suggestTagKeys = function(metric) {
+      return $q.when(this.tagKeys[metric] || []);
+    };
+
+    this._saveTagKeys = function(metricData) {
+      var tagKeys = Object.keys(metricData.tags);
+      _.each(metricData.aggregateTags, function(tag) {
+        tagKeys.push(tag);
+      });
+
+      this.tagKeys[metricData.metric] = tagKeys;
+    };
+
     this._performSuggestQuery = function(query, type) {
       return this._get('/api/suggest', {type: type, q: query, max: 1000}).then(function(result) {
         return result.data;

public/app/plugins/datasource/opentsdb/query_ctrl.ts

@@ -50,9 +50,7 @@ export class OpenTsQueryCtrl extends QueryCtrl {
     };
 
     this.suggestTagKeys = (query, callback) => {
-      this.datasource.metricFindQuery('suggest_tagk(' + query + ')')
-      .then(this.getTextValues)
-      .then(callback);
+      this.datasource.suggestTagKeys(this.target.metric).then(callback);
     };
 
     this.suggestTagValues = (query, callback) => {