add timescaledb option to postgres datasource

This adds an option to the postgres datasource config for
timescaledb support. When set to auto it will check for
timescaledb when testing the datasource.

When this option is enabled the $__timeGroup macro will
use the time_bucket function from timescaledb to group
times by an interval.

This also passes the datasource edit control to testDatasource
to allow for setting additional settings, this might be useful
for other datasources aswell which have optional or version
dependant features which can be queried.

pkg/tsdb/postgres/macros.go

@@ -130,13 +130,19 @@ func (m *postgresMacroEngine) evaluateMacro(name string, args []string) (string,
 				m.query.Model.Set("fillValue", floatVal)
 			}
 		}
-		return fmt.Sprintf("floor(extract(epoch from %s)/%v)*%v", args[0], interval.Seconds(), interval.Seconds()), nil
+
+		if m.query.DataSource.JsonData.Get("timescaledb").MustString("auto") == "enabled" {
+			return fmt.Sprintf("time_bucket('%vs',%s) AS time", interval.Seconds(), args[0]), nil
+		} else {
+			return fmt.Sprintf("floor(extract(epoch from %s)/%v)*%v AS time", args[0], interval.Seconds(), interval.Seconds()), nil
+		}
 	case "__timeGroupAlias":
 		tg, err := m.evaluateMacro("__timeGroup", args)
 		if err == nil {
 			return tg + " AS \"time\"", err
 		}
 		return "", err
+
 	case "__unixEpochFilter":
 		if len(args) == 0 {
 			return "", fmt.Errorf("missing time column argument for macro %v", name)

pkg/tsdb/postgres/macros_test.go

@@ -6,6 +6,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/grafana/grafana/pkg/components/simplejson"
+	"github.com/grafana/grafana/pkg/models"
 	"github.com/grafana/grafana/pkg/tsdb"
 	. "github.com/smartystreets/goconvey/convey"
 )
@@ -13,7 +15,9 @@ import (
 func TestMacroEngine(t *testing.T) {
 	Convey("MacroEngine", t, func() {
 		engine := newPostgresMacroEngine()
-		query := &tsdb.Query{}
+		query := &tsdb.Query{DataSource: &models.DataSource{JsonData: simplejson.New()}}
+		queryTS := &tsdb.Query{DataSource: &models.DataSource{JsonData: simplejson.New()}}
+		queryTS.DataSource.JsonData.Set("timescaledb", "enabled")
 
 		Convey("Given a time range between 2018-04-12 00:00 and 2018-04-12 00:05", func() {
 			from := time.Date(2018, 4, 12, 18, 0, 0, 0, time.UTC)
@@ -83,6 +87,22 @@ func TestMacroEngine(t *testing.T) {
 				So(sql2, ShouldEqual, sql+" AS \"time\"")
 			})
 
+			Convey("interpolate __timeGroup function with TimescaleDB enabled", func() {
+
+				sql, err := engine.Interpolate(queryTS, timeRange, "GROUP BY $__timeGroup(time_column,'5m')")
+				So(err, ShouldBeNil)
+
+				So(sql, ShouldEqual, "GROUP BY time_bucket('300s',time_column) AS time")
+			})
+
+			Convey("interpolate __timeGroup function with spaces between args and TimescaleDB enabled", func() {
+
+				sql, err := engine.Interpolate(queryTS, timeRange, "GROUP BY $__timeGroup(time_column , '5m')")
+				So(err, ShouldBeNil)
+
+				So(sql, ShouldEqual, "GROUP BY time_bucket('300s',time_column) AS time")
+			})
+
 			Convey("interpolate __timeTo function", func() {
 				sql, err := engine.Interpolate(query, timeRange, "select $__timeTo(time_column)")
 				So(err, ShouldBeNil)

pkg/tsdb/postgres/postgres_test.go

@@ -27,7 +27,7 @@ import (
 // use to verify that the generated data are vizualized as expected, see
 // devenv/README.md for setup instructions.
 func TestPostgres(t *testing.T) {
-	// change to true to run the MySQL tests
+	// change to true to run the PostgreSQL tests
 	runPostgresTests := false
 	// runPostgresTests := true
 
@@ -102,6 +102,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": "SELECT * FROM postgres_types",
 								"format": "table",
@@ -182,6 +183,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": "SELECT $__timeGroup(time, '5m') AS time, avg(value) as value FROM metric GROUP BY 1 ORDER BY 1",
 								"format": "time_series",
@@ -226,6 +228,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": "SELECT $__timeGroup(time, '5m', NULL) AS time, avg(value) as value FROM metric GROUP BY 1 ORDER BY 1",
 								"format": "time_series",
@@ -280,6 +283,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": "SELECT $__timeGroup(time, '5m', 1.5) AS time, avg(value) as value FROM metric GROUP BY 1 ORDER BY 1",
 								"format": "time_series",
@@ -401,6 +405,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT "timeInt64" as time, "timeInt64" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
@@ -423,6 +428,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT "timeInt64Nullable" as time, "timeInt64Nullable" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
@@ -445,6 +451,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT "timeFloat64" as time, "timeFloat64" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
@@ -467,6 +474,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT "timeFloat64Nullable" as time, "timeFloat64Nullable" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
@@ -511,6 +519,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT "timeInt32Nullable" as time, "timeInt32Nullable" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
@@ -533,6 +542,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT "timeFloat32" as time, "timeFloat32" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
@@ -555,6 +565,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT "timeFloat32Nullable" as time, "timeFloat32Nullable" FROM metric_values ORDER BY time LIMIT 1`,
 								"format": "time_series",
@@ -577,6 +588,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT $__timeEpoch(time), measurement || ' - value one' as metric, "valueOne" FROM metric_values ORDER BY 1`,
 								"format": "time_series",
@@ -625,6 +637,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT $__timeEpoch(time), "valueOne", "valueTwo" FROM metric_values ORDER BY 1`,
 								"format": "time_series",
@@ -682,6 +695,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT "time_sec" as time, description as text, tags FROM event WHERE $__unixEpochFilter(time_sec) AND tags='deploy' ORDER BY 1 ASC`,
 								"format": "table",
@@ -705,6 +719,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT "time_sec" as time, description as text, tags FROM event WHERE $__unixEpochFilter(time_sec) AND tags='ticket' ORDER BY 1 ASC`,
 								"format": "table",
@@ -731,6 +746,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": fmt.Sprintf(`SELECT
 									CAST('%s' AS TIMESTAMP) as time,
@@ -761,6 +777,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": fmt.Sprintf(`SELECT
 									 %d as time,
@@ -791,6 +808,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": fmt.Sprintf(`SELECT
 									 cast(%d as bigint) as time,
@@ -821,6 +839,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": fmt.Sprintf(`SELECT
 									 %d as time,
@@ -849,6 +868,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT
 									 cast(null as bigint) as time,
@@ -877,6 +897,7 @@ func TestPostgres(t *testing.T) {
 				query := &tsdb.TsdbQuery{
 					Queries: []*tsdb.Query{
 						{
+							DataSource: &models.DataSource{JsonData: simplejson.New()},
 							Model: simplejson.NewFromAny(map[string]interface{}{
 								"rawSql": `SELECT
 									 cast(null as timestamp) as time,

public/app/features/plugins/ds_edit_ctrl.ts

@@ -132,7 +132,7 @@ export class DataSourceEditCtrl {
       this.backendSrv
         .withNoBackendCache(() => {
           return datasource
-            .testDatasource()
+            .testDatasource(this)
             .then(result => {
               this.testing.message = result.message;
               this.testing.status = result.status;

public/app/plugins/datasource/postgres/datasource.ts

@@ -123,27 +123,27 @@ export class PostgresDatasource {
       .then(data => this.responseParser.parseMetricFindQueryResult(refId, data));
   }
 
-  testDatasource() {
+  testDatasource(control) {
-    return this.backendSrv
+    return this.metricFindQuery('SELECT 1', {})
-      .datasourceRequest({
-        url: '/api/tsdb/query',
-        method: 'POST',
-        data: {
-          from: '5m',
-          to: 'now',
-          queries: [
-            {
-              refId: 'A',
-              intervalMs: 1,
-              maxDataPoints: 1,
-              datasourceId: this.id,
-              rawSql: 'SELECT 1',
-              format: 'table',
-            },
-          ],
-        },
-      })
       .then(res => {
+        if (control.current.jsonData.timescaledb === 'auto') {
+          return this.metricFindQuery("SELECT 1 FROM pg_extension WHERE extname='timescaledb'", {})
+            .then(res => {
+              if (res.length === 1) {
+                control.current.jsonData.timescaledb = 'enabled';
+                return this.backendSrv.put('/api/datasources/' + this.id, control.current).then(settings => {
+                  control.current = settings.datasource;
+                  control.updateFrontendSettings();
+                  return { status: 'success', message: 'Database Connection OK, TimescaleDB found' };
+                });
+              }
+              throw new Error('timescaledb not found');
+            })
+            .catch(err => {
+              // query errored out or empty so timescaledb is not available
+              return { status: 'success', message: 'Database Connection OK' };
+            });
+        }
         return { status: 'success', message: 'Database Connection OK' };
       })
       .catch(err => {

public/app/plugins/datasource/postgres/partials/config.html

@@ -38,6 +38,20 @@
 	</div>
 </div>
 
+<h3 class="page-heading">PostgreSQL details</h3>
+
+<div class="gf-form-group">
+	<div class="gf-form">
+		<label class="gf-form-label width-7">TimescaleDB</label>
+		<div class="gf-form-select-wrapper max-width-8 gf-form-select-wrapper--has-help-icon">
+			<select class="gf-form-input" ng-model="ctrl.current.jsonData.timescaledb" ng-options="mode for mode in ['auto', 'enabled', 'disabled']" ng-init="ctrl.current.jsonData.timescaledb=ctrl.current.jsonData.timescaledb || 'auto'"></select>
+			<info-popover mode="right-absolute">
+				This option determines whether TimescaleDB features will be used.
+			</info-popover>
+		</div>
+	</div>
+</div>
+
 <div class="gf-form-group">
 	<div class="grafana-info-box">
 		<h5>User Permission</h5>