Broken DB connection no longer causes panic

gorm/transaction.go

@@ -3,6 +3,7 @@ package gorm
 import (
 	"context"
 	"errors"
+	"reflect"
 	"sync"
 
 	"github.com/infobloxopen/atlas-app-toolkit/rpc/errdetails"
@@ -89,6 +90,9 @@ func (t *Transaction) Rollback() error {
 	if t.current == nil {
 		return nil
 	}
+	if reflect.ValueOf(t.current.CommonDB()).IsNil() {
+		return status.Error(codes.Unavailable, "Database connection not available")
+	}
 	t.mu.Lock()
 	defer t.mu.Unlock()
 
@@ -101,7 +105,7 @@ func (t *Transaction) Rollback() error {
 // Commit finishes transaction by calling `*gorm.DB.Commit()`
 // Reset current transaction and returns an error if any.
 func (t *Transaction) Commit(ctx context.Context) error {
-	if t.current == nil {
+	if t.current == nil || reflect.ValueOf(t.current.CommonDB()).IsNil() {
 		return nil
 	}
 	t.mu.Lock()
@@ -150,6 +154,11 @@ func UnaryServerInterceptor(db *gorm.DB) grpc.UnaryServerInterceptor {
 			if terr == nil {
 				return
 			}
+			// Catch the status: UNAVAILABLE error that Rollback might return
+			if _, ok := status.FromError(terr); ok {
+				err = terr
+				return
+			}
 
 			st := status.Convert(err)
 			st, serr := st.WithDetails(errdetails.New(codes.Internal, "gorm", terr.Error()))

gorm/transaction_test.go

@@ -3,6 +3,7 @@ package gorm
 import (
 	"context"
 	"errors"
+	"reflect"
 	"testing"
 
 	"github.com/DATA-DOG/go-sqlmock"
@@ -240,6 +241,15 @@ func TestTransaction_Rollback(t *testing.T) {
 	if txn.current != nil {
 		t.Error("failed to reset current gorm instance - txn.current is not nil")
 	}
+
+	fdb, err := gorm.Open("postgres", db)
+	fdb.Close()
+	txn = &Transaction{parent: gdb}
+
+	txn.Begin()
+	if err := txn.Rollback(); !reflect.DeepEqual(err, status.Error(codes.Unavailable, "Database connection not available")) {
+		t.Errorf("Did not receive proper error for broken DB - %s", err)
+	}
 }
 
 func TestContext(t *testing.T) {