[authz]: use authlib client (#91205)

authz: use authlib client

Co-authored-by: Gabriel MABILLE <gabriel.mabille@grafana.com>

pkg/services/authz/config.go

@@ -10,7 +10,7 @@ type Mode string
 
 func (s Mode) IsValid() bool {
 	switch s {
-	case ModeGRPC, ModeInProc:
+	case ModeGRPC, ModeInProc, ModeCloud:
 		return true
 	}
 	return false
@@ -19,12 +19,17 @@ func (s Mode) IsValid() bool {
 const (
 	ModeGRPC   Mode = "grpc"
 	ModeInProc Mode = "inproc"
+	ModeCloud  Mode = "cloud"
 )
 
 type Cfg struct {
 	remoteAddress string
 	listen        bool
 	mode          Mode
+
+	token            string
+	tokenExchangeURL string
+	tokenNamespace   string
 }
 
 func ReadCfg(cfg *setting.Cfg) (*Cfg, error) {
@@ -35,9 +40,20 @@ func ReadCfg(cfg *setting.Cfg) (*Cfg, error) {
 		return nil, fmt.Errorf("authorization: invalid mode %q", mode)
 	}
 
+	token := section.Key("token").MustString("")
+	tokenExchangeURL := section.Key("token_exchange_url").MustString("")
+	tokenNamespace := section.Key("token_namespace").MustString("stack-" + cfg.StackID)
+
+	if mode == ModeCloud && token == "" && tokenExchangeURL == "" {
+		return nil, fmt.Errorf("authorization:  missing token or tokenExchangeUrl")
+	}
+
 	return &Cfg{
-		remoteAddress: section.Key("remote_address").MustString(""),
-		listen:        section.Key("listen").MustBool(false),
-		mode:          mode,
+		remoteAddress:    section.Key("remote_address").MustString(""),
+		listen:           section.Key("listen").MustBool(false),
+		mode:             mode,
+		token:            token,
+		tokenExchangeURL: tokenExchangeURL,
+		tokenNamespace:   tokenNamespace,
 	}, nil
 }