adds server lock package

pkg/infra/serverlock/serverlock_test.go

@@ -0,0 +1,57 @@
+package serverlock
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/grafana/grafana/pkg/log"
+
+	"github.com/grafana/grafana/pkg/services/sqlstore"
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func createTestableServerLock(t *testing.T) *ServerLockService {
+	t.Helper()
+
+	sqlstore := sqlstore.InitTestDB(t)
+
+	return &ServerLockService{
+		SQLStore: sqlstore,
+		log:      log.New("test-logger"),
+	}
+}
+
+func TestServerLock(t *testing.T) {
+	Convey("Server lock", t, func() {
+		sl := createTestableServerLock(t)
+		operationUID := "test-operation"
+
+		first, err := sl.getOrCreate(context.Background(), operationUID)
+		So(err, ShouldBeNil)
+
+		lastExecution := first.LastExecution
+		Convey("trying to create three new row locks", func() {
+			for i := 0; i < 3; i++ {
+				first, err = sl.getOrCreate(context.Background(), operationUID)
+				So(err, ShouldBeNil)
+				So(first.OperationUid, ShouldEqual, operationUID)
+				So(first.Id, ShouldEqual, 1)
+			}
+
+			Convey("Should not create new since lock already exist", func() {
+				So(lastExecution, ShouldEqual, first.LastExecution)
+			})
+		})
+
+		Convey("Should be able to create lock on first row", func() {
+			gotLock, err := sl.acquireLock(context.Background(), first, time.Second*1)
+			So(err, ShouldBeNil)
+			So(gotLock, ShouldBeTrue)
+
+			gotLock, err = sl.acquireLock(context.Background(), first, time.Second*1)
+			So(err, ShouldBeNil)
+			So(gotLock, ShouldBeFalse)
+		})
+	})
+}