Avoid config migration on every startup (#16278)

cmd/admin-handlers-config-kv.go

@@ -71,7 +71,7 @@ func (a adminAPIHandlers) DelConfigKVHandler(w http.ResponseWriter, r *http.Requ
 		return
 	}
 
-	cfg, err := readServerConfig(ctx, objectAPI)
+	cfg, err := readServerConfig(ctx, objectAPI, nil)
 	if err != nil {
 		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
 		return
@@ -142,7 +142,7 @@ func (a adminAPIHandlers) SetConfigKVHandler(w http.ResponseWriter, r *http.Requ
 		return
 	}
 
-	cfg, err := readServerConfig(ctx, objectAPI)
+	cfg, err := readServerConfig(ctx, objectAPI, nil)
 	if err != nil {
 		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
 		return
@@ -296,7 +296,7 @@ func (a adminAPIHandlers) RestoreConfigHistoryKVHandler(w http.ResponseWriter, r
 		return
 	}
 
-	cfg, err := readServerConfig(ctx, objectAPI)
+	cfg, err := readServerConfig(ctx, objectAPI, nil)
 	if err != nil {
 		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
 		return

cmd/admin-handlers-idp-config.go

@@ -107,7 +107,7 @@ func (a adminAPIHandlers) addOrUpdateIDPHandler(ctx context.Context, w http.Resp
 		cfgData = subSys + tgtSuffix + config.KvSpaceSeparator + string(reqBytes)
 	}
 
-	cfg, err := readServerConfig(ctx, objectAPI)
+	cfg, err := readServerConfig(ctx, objectAPI, nil)
 	if err != nil {
 		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
 		return
@@ -408,7 +408,7 @@ func (a adminAPIHandlers) DeleteIdentityProviderCfg(w http.ResponseWriter, r *ht
 		return
 	}
 
-	cfg, err := readServerConfig(ctx, objectAPI)
+	cfg, err := readServerConfig(ctx, objectAPI, nil)
 	if err != nil {
 		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
 		return

cmd/admin-handlers.go

@@ -2135,7 +2135,7 @@ func fetchHealthInfo(healthCtx context.Context, objectAPI ObjectLayer, query *ur
 
 	getAndWriteMinioConfig := func() {
 		if query.Get("minioconfig") == "true" {
-			config, err := readServerConfig(healthCtx, objectAPI)
+			config, err := readServerConfig(healthCtx, objectAPI, nil)
 			if err != nil {
 				healthInfo.Minio.Config = madmin.MinioConfig{
 					Error: err.Error(),

cmd/config-current.go

@@ -782,13 +782,14 @@ func newSrvConfig(objAPI ObjectLayer) error {
 }
 
 func getValidConfig(objAPI ObjectLayer) (config.Config, error) {
-	return readServerConfig(GlobalContext, objAPI)
+	return readServerConfig(GlobalContext, objAPI, nil)
 }
 
 // loadConfig - loads a new config from disk, overrides params
 // from env if found and valid
-func loadConfig(objAPI ObjectLayer) error {
+// data is optional. If nil it will be loaded from backend.
-	srvCfg, err := getValidConfig(objAPI)
+func loadConfig(objAPI ObjectLayer, data []byte) error {
+	srvCfg, err := readServerConfig(GlobalContext, objAPI, data)
 	if err != nil {
 		return err
 	}

cmd/config-current_test.go

@@ -61,7 +61,7 @@ func TestServerConfig(t *testing.T) {
 	}
 
 	// Initialize server config.
-	if err := loadConfig(objLayer); err != nil {
+	if err := loadConfig(objLayer, nil); err != nil {
 		t.Fatalf("Unable to initialize from updated config file %s", err)
 	}
 }

cmd/config-migrate.go

@@ -2533,6 +2533,21 @@ func checkConfigVersion(objAPI ObjectLayer, configFile string, version string) (
 		}
 	}
 
+	if version == "kvs" {
+		// Check api config values are present.
+		var vcfg struct {
+			API struct {
+				E []struct {
+					Key   string `json:"key"`
+					Value string `json:"value"`
+				} `json:"_"`
+			} `json:"api"`
+		}
+		if err = json.Unmarshal(data, &vcfg); err != nil {
+			return false, nil, nil
+		}
+		return len(vcfg.API.E) > 0, data, nil
+	}
 	var versionConfig struct {
 		Version string `json:"version"`
 	}

cmd/config-migrate_test.go

@@ -65,7 +65,7 @@ func TestServerConfigMigrateV1(t *testing.T) {
 	}
 
 	// Initialize server config and check again if everything is fine
-	if err := loadConfig(objLayer); err != nil {
+	if err := loadConfig(objLayer, nil); err != nil {
 		t.Fatalf("Unable to initialize from updated config file %s", err)
 	}
 }
@@ -207,7 +207,7 @@ func TestServerConfigMigrateV2toV33(t *testing.T) {
 	}
 
 	// Initialize server config and check again if everything is fine
-	if err := loadConfig(objLayer); err != nil {
+	if err := loadConfig(objLayer, nil); err != nil {
 		t.Fatalf("Unable to initialize from updated config file %s", err)
 	}
 

cmd/config.go

@@ -152,30 +152,34 @@ func saveServerConfig(ctx context.Context, objAPI ObjectLayer, cfg interface{})
 	return saveConfig(ctx, objAPI, configFile, data)
 }
 
-func readServerConfig(ctx context.Context, objAPI ObjectLayer) (config.Config, error) {
+// data is optional. If nil it will be loaded from backend.
+func readServerConfig(ctx context.Context, objAPI ObjectLayer, data []byte) (config.Config, error) {
 	srvCfg := config.New()
-	configFile := path.Join(minioConfigPrefix, minioConfigFile)
+	var err error
-	data, err := readConfig(ctx, objAPI, configFile)
+	if len(data) == 0 {
-	if err != nil {
+		configFile := path.Join(minioConfigPrefix, minioConfigFile)
-		if errors.Is(err, errConfigNotFound) {
+		data, err = readConfig(ctx, objAPI, configFile)
-			lookupConfigs(srvCfg, objAPI)
-			return srvCfg, nil
-		}
-		return nil, err
-	}
-
-	if GlobalKMS != nil && !utf8.Valid(data) {
-		data, err = config.DecryptBytes(GlobalKMS, data, kms.Context{
-			minioMetaBucket: path.Join(minioMetaBucket, configFile),
-		})
 		if err != nil {
-			lookupConfigs(srvCfg, objAPI)
+			if errors.Is(err, errConfigNotFound) {
+				lookupConfigs(srvCfg, objAPI)
+				return srvCfg, nil
+			}
 			return nil, err
 		}
+
+		if GlobalKMS != nil && !utf8.Valid(data) {
+			data, err = config.DecryptBytes(GlobalKMS, data, kms.Context{
+				minioMetaBucket: path.Join(minioMetaBucket, configFile),
+			})
+			if err != nil {
+				lookupConfigs(srvCfg, objAPI)
+				return nil, err
+			}
+		}
 	}
 
 	json := jsoniter.ConfigCompatibleWithStandardLibrary
-	if err = json.Unmarshal(data, &srvCfg); err != nil {
+	if err := json.Unmarshal(data, &srvCfg); err != nil {
 		return nil, err
 	}
 
@@ -212,6 +216,15 @@ func initConfig(objAPI ObjectLayer) error {
 		}
 	}
 
+	// Check if the config version is latest (kvs), if not migrate.
+	ok, data, err := checkConfigVersion(objAPI, path.Join(minioConfigPrefix, minioConfigFile), "kvs")
+	if err != nil && !errors.Is(err, errConfigNotFound) {
+		return err
+	}
+	if ok {
+		return loadConfig(objAPI, data)
+	}
+
 	// Migrates ${HOME}/.minio/config.json or config.json.deprecated
 	// to '<export_path>/.minio.sys/config/config.json'
 	// ignore if the file doesn't exist.
@@ -232,5 +245,5 @@ func initConfig(objAPI ObjectLayer) error {
 		return fmt.Errorf("migrateMinioSysConfigToKV: %w", err)
 	}
 
-	return loadConfig(objAPI)
+	return loadConfig(objAPI, nil)
 }