added No-Cache headers to server endpoints which should not cache. cl…

…oses go-spatial#176

CHANGELOG.md

@@ -1,13 +1,16 @@
 ## 0.5.0 (2017-12-XX)
-- Added: Command line `cache seed` and `cache purge` commands
-- Added: More robust command line interface
-- Added: Support for Amazon S3 as a cache backend
+
+- Added: Command line `cache seed` and `cache purge` commands (#64)
+- Added: Support for Amazon S3 as a cache backend (#64)
+- Added: More robust command line interface (#64)
+- Added: No-Cache headers to `/capabilities`, `/capabilities/:map_name` and `/maps/:map_name/style.json` endpoints. (#176)
 - Fixed: Possible Panic if a feature without an ID is added before a feature with an ID; when constructing Layers (#195)
 
 Breaking changes:
 - To use tegola as a web server, use the command `tegola serve --config=/path/to/config.toml`
 
 ## 0.4.2 (2017-11-28)
+
 - Fixed: Performance affected by unused log statements (#197, @remster)
 
 ## 0.4.1 (2017-11-21)

server/handle_capabilities.go

@@ -125,6 +125,14 @@ func (req HandleCapabilities) ServeHTTP(w http.ResponseWriter, r *http.Request)
 			capabilities.Maps = append(capabilities.Maps, cMap)
 		}
 
+		//	content type
+		w.Header().Add("Content-Type", "application/json")
+
+		//	cache control headers (no-cache)
+		w.Header().Add("Cache-Control", "no-cache, no-store, must-revalidate")
+		w.Header().Add("Pragma", "no-cache")
+		w.Header().Add("Expires", "0")
+
 		//	setup a new json encoder and encode our capabilities
 		json.NewEncoder(w).Encode(capabilities)
 	}

server/handle_map_capabilities.go

@@ -170,9 +170,14 @@ func (req HandleMapCapabilities) ServeHTTP(w http.ResponseWriter, r *http.Reques
 		//	set CORS header
 		w.Header().Add("Access-Control-Allow-Origin", "*")
 
-		//	mimetype for protocol buffers
+		//	content type
 		w.Header().Add("Content-Type", "application/json")
 
+		//	cache control headers (no-cache)
+		w.Header().Add("Cache-Control", "no-cache, no-store, must-revalidate")
+		w.Header().Add("Pragma", "no-cache")
+		w.Header().Add("Expires", "0")
+
 		if err = json.NewEncoder(w).Encode(tileJSON); err != nil {
 			log.Printf("error encoding tileJSON for map (%v)", req.mapName)
 		}

server/handle_map_style.go

@@ -152,6 +152,11 @@ func (req HandleMapStyle) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	//	mimetype for protocol buffers
 	w.Header().Add("Content-Type", "application/json")
 
+	//	cache control headers (no-cache)
+	w.Header().Add("Cache-Control", "no-cache, no-store, must-revalidate")
+	w.Header().Add("Pragma", "no-cache")
+	w.Header().Add("Expires", "0")
+
 	if err = json.NewEncoder(w).Encode(mapboxStyle); err != nil {
 		log.Printf("error encoding tileJSON for map (%v)", req.mapName)
 	}