CDN: Adds support for serving assets over a CDN (#30691)

* CDN: Initial poc support for serving assets over a CDN

* Minor fix

* added build path and test

* fix lint error

* Added edition to cdn path

* Move master builds to a separate path

* Added error handling for the url parsing, changed setting name, and added docs

* Updated sample.ini

* Some property renames

* updated

* Minor update to html

* index template improvements

* Update docs/sources/administration/configuration.md

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

* Update docs/sources/administration/configuration.md

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

* Added ContentDeliveryPrefix to Licence service

* updated docs

* Updated test mock

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

pkg/api/dtos/index.go

@@ -25,6 +25,7 @@ type IndexViewData struct {
 	AppleTouchIcon          template.URL
 	AppTitle                string
 	Sentry                  *setting.Sentry
+	ContentDeliveryURL      string
 	// Nonce is a cryptographic identifier for use with Content Security Policy.
 	Nonce string
 }

pkg/api/index.go

@@ -428,6 +428,7 @@ func (hs *HTTPServer) setIndexViewData(c *models.ReqContext) (*dtos.IndexViewDat
 		NavTree:                 navTree,
 		Sentry:                  &hs.Cfg.Sentry,
 		Nonce:                   c.RequestNonce,
+		ContentDeliveryURL:      hs.Cfg.GetContentDeliveryURL((hs.License.Edition())),
 	}
 
 	if setting.DisableGravatar {