SQLStore: customise the limit of retrieved datasources per organisation (#29358)

* SQLStore: customise the limit of retrieved datasources per organisation

* update all suggestions regarding nil or 0 as default

* Apply suggestions from code review

Co-authored-by: Emil Tullstedt <emil.tullstedt@grafana.com>

* correct default.ini description + adding unittest

* Apply suggestions from code review

Co-authored-by: Sofia Papagiannaki <papagian@users.noreply.github.com>

* modify unittest name

Co-authored-by: Emil Tullstedt <emil.tullstedt@grafana.com>
Co-authored-by: Sofia Papagiannaki <papagian@users.noreply.github.com>

pkg/services/sqlstore/datasource.go

@@ -67,8 +67,12 @@ func GetDataSourceByName(query *models.GetDataSourceByNameQuery) error {
 }
 
 func GetDataSources(query *models.GetDataSourcesQuery) error {
-	sess := x.Limit(5000, 0).Where("org_id=?", query.OrgId).Asc("name")
-
+	var sess *xorm.Session
+	if query.DataSourceLimit <= 0 {
+		sess = x.Where("org_id=?", query.OrgId).Asc("name")
+	} else {
+		sess = x.Limit(query.DataSourceLimit, 0).Where("org_id=?", query.OrgId).Asc("name")
+	}
 	query.Result = make([]*models.DataSource, 0)
 	return sess.Find(&query.Result)
 }

pkg/services/sqlstore/datasource_test.go

@@ -3,6 +3,7 @@
 package sqlstore
 
 import (
+	"strconv"
 	"testing"
 
 	"github.com/grafana/grafana/pkg/models"
@@ -214,4 +215,75 @@ func TestDataAccess(t *testing.T) {
 
 		require.Equal(t, 0, len(query.Result))
 	})
+
+	t.Run("GetDataSource", func(t *testing.T) {
+		t.Run("Number of data sources returned limited to 6 per organization", func(t *testing.T) {
+			InitTestDB(t)
+			datasourceLimit := 6
+			for i := 0; i < datasourceLimit+1; i++ {
+				err := AddDataSource(&models.AddDataSourceCommand{
+					OrgId:    10,
+					Name:     "laban" + strconv.Itoa(i),
+					Type:     models.DS_GRAPHITE,
+					Access:   models.DS_ACCESS_DIRECT,
+					Url:      "http://test",
+					Database: "site",
+					ReadOnly: true,
+				})
+				require.NoError(t, err)
+			}
+			query := models.GetDataSourcesQuery{OrgId: 10, DataSourceLimit: datasourceLimit}
+
+			err := GetDataSources(&query)
+
+			require.NoError(t, err)
+			require.Equal(t, datasourceLimit, len(query.Result))
+		})
+
+		t.Run("No limit should be applied on the returned data sources if the limit is not set", func(t *testing.T) {
+			InitTestDB(t)
+			numberOfDatasource := 5100
+			for i := 0; i < numberOfDatasource; i++ {
+				err := AddDataSource(&models.AddDataSourceCommand{
+					OrgId:    10,
+					Name:     "laban" + strconv.Itoa(i),
+					Type:     models.DS_GRAPHITE,
+					Access:   models.DS_ACCESS_DIRECT,
+					Url:      "http://test",
+					Database: "site",
+					ReadOnly: true,
+				})
+				require.NoError(t, err)
+			}
+			query := models.GetDataSourcesQuery{OrgId: 10}
+
+			err := GetDataSources(&query)
+
+			require.NoError(t, err)
+			require.Equal(t, numberOfDatasource, len(query.Result))
+		})
+
+		t.Run("No limit should be applied on the returned data sources if the limit is negative", func(t *testing.T) {
+			InitTestDB(t)
+			numberOfDatasource := 5100
+			for i := 0; i < numberOfDatasource; i++ {
+				err := AddDataSource(&models.AddDataSourceCommand{
+					OrgId:    10,
+					Name:     "laban" + strconv.Itoa(i),
+					Type:     models.DS_GRAPHITE,
+					Access:   models.DS_ACCESS_DIRECT,
+					Url:      "http://test",
+					Database: "site",
+					ReadOnly: true,
+				})
+				require.NoError(t, err)
+			}
+			query := models.GetDataSourcesQuery{OrgId: 10, DataSourceLimit: -1}
+
+			err := GetDataSources(&query)
+
+			require.NoError(t, err)
+			require.Equal(t, numberOfDatasource, len(query.Result))
+		})
+	})
 }

pkg/services/sqlstore/sqlstore.go

@@ -354,7 +354,7 @@ func (ss *SQLStore) readConfig() {
 	ss.dbCfg.CacheMode = sec.Key("cache_mode").MustString("private")
 }
 
-// Interface of arguments for testing db
+// ITestDB is an interface of arguments for testing db
 type ITestDB interface {
 	Helper()
 	Fatalf(format string, args ...interface{})