Zanzana: Initial work to run openFGA as embedded or standalone service (#89211)

* Zanana: Initial work to run zanana as ebeddedn or standalone

* Add addr settings for when remote client is used.

* sync dependencies

* Lock mysql driver version
---------

Co-authored-by: Dan Cech <dcech@grafana.com>

pkg/setting/setting.go

@@ -475,6 +475,8 @@ type Cfg struct {
 	// RBAC single organization. This configuration option is subject to change.
 	RBACSingleOrganization bool
 
+	Zanzana ZanzanaSettings
+
 	// GRPC Server.
 	GRPCServerNetwork        string
 	GRPCServerAddress        string
@@ -1113,6 +1115,9 @@ func (cfg *Cfg) parseINIFile(iniFile *ini.File) error {
 	readOAuth2ServerSettings(cfg)
 
 	readAccessControlSettings(iniFile, cfg)
+
+	cfg.readZanzanaSettings()
+
 	if err := cfg.readRenderingSettings(iniFile); err != nil {
 		return err
 	}

pkg/setting/settings_zanzana.go

@@ -0,0 +1,37 @@
+package setting
+
+import (
+	"slices"
+)
+
+type ZanzanaMode string
+
+const (
+	ZanzanaModeClient   ZanzanaMode = "client"
+	ZanzanaModeEmbedded ZanzanaMode = "embedded"
+)
+
+type ZanzanaSettings struct {
+	// Addr is only used when mode is set to client
+	Addr string
+	// Mode can either be embedded or client
+	Mode ZanzanaMode
+}
+
+func (cfg *Cfg) readZanzanaSettings() {
+	s := ZanzanaSettings{}
+
+	sec := cfg.Raw.Section("zanzana")
+	s.Mode = ZanzanaMode(sec.Key("mode").MustString("embedded"))
+
+	validModes := []ZanzanaMode{ZanzanaModeEmbedded, ZanzanaModeClient}
+
+	if !slices.Contains(validModes, s.Mode) {
+		cfg.Logger.Warn("Invalid zanzana mode", "expected", validModes, "got", s.Mode)
+		s.Mode = "embedded"
+	}
+
+	s.Addr = sec.Key("address").MustString("")
+
+	cfg.Zanzana = s
+}