Anonymous: Add configurable device limit (#79265)

* Anonymous: Add device limiter

* break auth if limit reached

* fix typo

* refactored const to make it clearer with expiration

* anon device limit for config

---------

Co-authored-by: Eric Leijonmarck <eric.leijonmarck@gmail.com>

pkg/api/dtos/frontend_settings.go

@@ -192,6 +192,7 @@ type FrontendSettingsDTO struct {
 
 	FeatureToggles                   map[string]bool                `json:"featureToggles"`
 	AnonymousEnabled                 bool                           `json:"anonymousEnabled"`
+	AnonymousDeviceLimit             int64                          `json:"anonymousDeviceLimit"`
 	RendererAvailable                bool                           `json:"rendererAvailable"`
 	RendererVersion                  string                         `json:"rendererVersion"`
 	SecretsManagerPluginEnabled      bool                           `json:"secretsManagerPluginEnabled"`

pkg/api/frontendsettings.go

@@ -195,6 +195,7 @@ func (hs *HTTPServer) getFrontendSettings(c *contextmodel.ReqContext) (*dtos.Fro
 
 		FeatureToggles:                   hs.Features.GetEnabled(c.Req.Context()),
 		AnonymousEnabled:                 hs.Cfg.AnonymousEnabled,
+		AnonymousDeviceLimit:             hs.Cfg.AnonymousDeviceLimit,
 		RendererAvailable:                hs.RenderService.IsAvailable(c.Req.Context()),
 		RendererVersion:                  hs.RenderService.Version(),
 		SecretsManagerPluginEnabled:      secretsManagerPluginEnabled,