Praefect: server factory introduction

Introduces server factory for creating gRPC servers.
Praefect gRPC server created by separate function and
can be reused in tests to check routing.

Part of: https://gitlab.com/gitlab-org/gitaly/-/issues/1698

2 files changed, 7 insertions, 5 deletions

diff --git a/internal/bootstrap/starter/starter.go b/internal/bootstrap/starter/starter.go
index 7c43781af..a8b7c018c 100644
--- a/internal/bootstrap/starter/starter.go
+++ b/internal/bootstrap/starter/starter.go
@@ -23,7 +23,8 @@ const (
 )
 
 var (
-	errEmptySchema  = errors.New("empty schema can't be used")
+	// ErrEmptySchema signals that the address has no schema in it.
+	ErrEmptySchema  = errors.New("empty schema can't be used")
 	errEmptyAddress = errors.New("empty address can't be used")
 )
 
@@ -36,7 +37,7 @@ func ParseEndpoint(endpoint string) (Config, error) {
 
 	parts := strings.Split(endpoint, separator)
 	if len(parts) != 2 {
-		return Config{}, fmt.Errorf("unsupported format: %q", endpoint)
+		return Config{}, fmt.Errorf("unsupported format: %q: %w", endpoint, ErrEmptySchema)
 	}
 
 	if err := verifySchema(parts[0]); err != nil {
@@ -65,7 +66,7 @@ func ComposeEndpoint(schema, address string) (string, error) {
 func verifySchema(schema string) error {
 	switch schema {
 	case "":
-		return errEmptySchema
+		return ErrEmptySchema
 	case TCP, TLS, Unix:
 		return nil
 	default:
diff --git a/internal/bootstrap/starter/starter_test.go b/internal/bootstrap/starter/starter_test.go
index 7347d0e13..c5d84b1f8 100644
--- a/internal/bootstrap/starter/starter_test.go
+++ b/internal/bootstrap/starter/starter_test.go
@@ -2,6 +2,7 @@ package starter
 
 import (
 	"errors"
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -110,12 +111,12 @@ func TestParseEndpoint(t *testing.T) {
 		{
 			desc:   "no schema",
 			addr:   "://127.0.0.1:2306",
-			expErr: errEmptySchema,
+			expErr: ErrEmptySchema,
 		},
 		{
 			desc:   "bad format",
 			addr:   "127.0.0.1:2306",
-			expErr: errors.New(`unsupported format: "127.0.0.1:2306"`),
+			expErr: fmt.Errorf(`unsupported format: "127.0.0.1:2306": %w`, ErrEmptySchema),
 		},
 		{
 			desc: "tcp schema addresses",