allow to disable REST API

Fixes #987

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/httpd/httpd.go

@@ -410,6 +410,8 @@ type Binding struct {
 	// Enable the built-in client interface.
 	// You have to define TemplatesPath and StaticFilesPath for this to work
 	EnableWebClient bool `json:"enable_web_client" mapstructure:"enable_web_client"`
+	// Enable REST API
+	EnableRESTAPI bool `json:"enable_rest_api" mapstructure:"enable_rest_api"`
 	// Defines the login methods available for the WebAdmin and WebClient UIs:
 	//
 	// - 0 means any configured method: username/password login form and OIDC, if enabled
@@ -522,6 +524,9 @@ func (b *Binding) GetAddress() string {
 
 // IsValid returns true if the binding is valid
 func (b *Binding) IsValid() bool {
+	if !b.EnableRESTAPI && !b.EnableWebAdmin && !b.EnableWebClient {
+		return false
+	}
 	if b.Port > 0 {
 		return true
 	}