disable inviting new users to orgs if login form is disabled

pkg/api/frontendsettings.go

@@ -142,6 +142,7 @@ func getFrontendSettingsMap(c *middleware.Context) (map[string]interface{}, erro
 		"ldapEnabled":       setting.LdapEnabled,
 		"alertingEnabled":   setting.AlertingEnabled,
 		"googleAnalyticsId": setting.GoogleAnalyticsId,
+		"disableLoginForm":  setting.DisableLoginForm,
 		"buildInfo": map[string]interface{}{
 			"version":       setting.BuildVersion,
 			"commit":        setting.BuildCommit,

pkg/api/login.go

@@ -94,6 +94,10 @@ func LoginApiPing(c *middleware.Context) {
 }
 
 func LoginPost(c *middleware.Context, cmd dtos.LoginCommand) Response {
+	if setting.DisableLoginForm {
+		return ApiError(401, "Login is disabled", nil)
+	}
+
 	authQuery := login.LoginUserQuery{
 		Username: cmd.User,
 		Password: cmd.Password,

pkg/api/org_invite.go

@@ -38,6 +38,10 @@ func AddOrgInvite(c *middleware.Context, inviteDto dtos.AddInviteForm) Response
 		if err != m.ErrUserNotFound {
 			return ApiError(500, "Failed to query db for existing user check", err)
 		}
+
+		if setting.DisableLoginForm {
+			return ApiError(401, "User could not be found", nil)
+		}
 	} else {
 		return inviteExistingUserToOrg(c, userQuery.Result, &inviteDto)
 	}