Merge pull request grafana#5343 from utkarshcmu/opentsdb-template

Implemented nested template variables functionality for Opentsdb

Author: bergquist

CHANGELOG.md

@@ -11,6 +11,7 @@
 * **Scripts**: Use restart instead of start for deb package script, closes [#5282](https://github.com/grafana/grafana/pull/5282)
 * **Logging**: Moved to structured logging lib, and moved to component specific level filters via config file, closes [#4590](https://github.com/grafana/grafana/issues/4590)
 * **Search**: Add search limit query parameter, closes [#5292](https://github.com/grafana/grafana/pull/5292)
+* **OpenTSDB**: Support nested template variables in tag_values function, closes [4398](https://github.com/grafana/grafana/issues/4398)
 
 ## Breaking changes
 * **Logging** : Changed default logging output format (now structured into message, and key value pairs, with logger key acting as component). You can also no change in config to json log ouput.

docs/sources/datasources/opentsdb.md

@@ -51,6 +51,13 @@ When using OpenTSDB with a template variable of `query` type you can use followi
 
 If you do not see template variables being populated in `Preview of values` section, you need to enable `tsd.core.meta.enable_realtime_ts` in the OpenTSDB server settings. Also, to populate metadata of the existing time series data in OpenTSDB, you need to run `tsdb uid metasync` on the OpenTSDB server.
 
+### Nested Templating
+
+One template variable can be used to filter tag values for another template varible. Very importantly, the order of the parameters matter in tag_values function. First parameter is the metric name, second parameter is the tag key for which you need to find tag values, and after that all other dependent template variables. Some examples are mentioned below to make nested template queries work successfully.
+
+    tag_values(cpu, hostname, env=$env)                   // return tag values for cpu metric, selected env tag value and tag key hostname 
+    tag_values(cpu, hostanme, env=$env, region=$region)   // return tag values for cpu metric, selected env tag value, selected region tag value and tag key hostname
+
 > Note: This is required for the OpenTSDB `lookup` api to work.
 
 For details on opentsdb metric queries checkout the official [OpenTSDB documentation](http://opentsdb.net/docs/build/html/index.html)

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

@@ -162,12 +162,23 @@ function (angular, _, dateMath) {
       });
     };
 
-    this._performMetricKeyValueLookup = function(metric, key) {
-      if(!metric || !key) {
+    this._performMetricKeyValueLookup = function(metric, keys) {
+
+      if(!metric || !keys) {
         return $q.when([]);
       }
 
-      var m = metric + "{" + key + "=*}";
+      var keysArray = keys.split(",").map(function(key) {
+        return key.trim();
+      });
+      var key = keysArray[0];
+      var keysQuery = key + "=*";
+
+      if (keysArray.length > 1) {
+        keysQuery += "," + keysArray.splice(1).join(",");
+      }
+
+      var m = metric + "{" + keysQuery + "}";
 
       return this._get('/api/search/lookup', {m: m, limit: 3000}).then(function(result) {
         result = result.data.results;
@@ -225,7 +236,7 @@ function (angular, _, dateMath) {
 
       var metrics_regex = /metrics\((.*)\)/;
       var tag_names_regex = /tag_names\((.*)\)/;
-      var tag_values_regex = /tag_values\((.*),\s?(.*)\)/;
+      var tag_values_regex = /tag_values\((.*?),\s?(.*)\)/;
       var tag_names_suggest_regex = /suggest_tagk\((.*)\)/;
       var tag_values_suggest_regex = /suggest_tagv\((.*)\)/;
 

public/app/plugins/datasource/opentsdb/specs/datasource-specs.ts

@@ -51,6 +51,20 @@ describe('opentsdb', function() {
       expect(requestOptions.params.m).to.be('cpu{hostname=*}');
     });
 
+    it('tag_values(cpu, test) should generate lookup query', function() {
+      ctx.ds.metricFindQuery('tag_values(cpu, hostname, env=$env)').then(function(data) { results = data; });
+      ctx.$rootScope.$apply();
+      expect(requestOptions.url).to.be('/api/search/lookup');
+      expect(requestOptions.params.m).to.be('cpu{hostname=*,env=$env}');
+    });
+
+    it('tag_values(cpu, test) should generate lookup query', function() {
+      ctx.ds.metricFindQuery('tag_values(cpu, hostname, env=$env, region=$region)').then(function(data) { results = data; });
+      ctx.$rootScope.$apply();
+      expect(requestOptions.url).to.be('/api/search/lookup');
+      expect(requestOptions.params.m).to.be('cpu{hostname=*,env=$env,region=$region}');
+    });
+
     it('suggest_tagk() should generate api suggest query', function() {
       ctx.ds.metricFindQuery('suggest_tagk(foo)').then(function(data) { results = data; });
       ctx.$rootScope.$apply();