[Bugfix] Fix ActiveFailover instance check (#282)

Author: ajanikow

service/service.go

@@ -729,6 +729,10 @@ func (s *Service) TestInstance(ctx context.Context, serverType definitions.Serve
 
 			resp, err := c.Do(ctx, req)
 			if err != nil {
+				if driver.IsNoLeader(err) {
+					// Server is up, just not the leader
+					return false, nil
+				}
 				return false, maskAny(err)
 			}
 			if resp.StatusCode() == 200 {

test/server_util.go

@@ -26,12 +26,13 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
-	"github.com/pkg/errors"
 	"net"
 	"net/http"
 	"testing"
 	"time"
 
+	"github.com/pkg/errors"
+
 	"github.com/arangodb-helper/arangodb/client"
 	"github.com/arangodb-helper/arangodb/service"
 	"github.com/arangodb/go-driver"