GZip compression for app HTTP endpoints and probe -> app communication.

app/router.go

@@ -1,11 +1,14 @@
 package main
 
 import (
+	"compress/gzip"
 	"encoding/gob"
+	"io"
 	"net/http"
 	"net/url"
 	"strings"
 
+	"github.com/PuerkitoBio/ghost/handlers"
 	"github.com/gorilla/mux"
 
 	"github.com/weaveworks/scope/render"
@@ -49,29 +52,49 @@ type collector interface {
 	xfer.Adder
 }
 
+func gzipHandler(h http.HandlerFunc) http.HandlerFunc {
+	return handlers.GZIPHandlerFunc(h, nil)
+}
+
 // Router returns the HTTP dispatcher, managing API and UI requests, and
 // accepting reports from probes.. It will always use the embedded HTML
 // resources for the UI.
 func Router(c collector) *mux.Router {
 	router := mux.NewRouter()
 	router.HandleFunc("/api/report", makeReportPostHandler(c)).Methods("POST")
+
 	get := router.Methods("GET").Subrouter()
-	get.HandleFunc("/api", apiHandler)
-	get.HandleFunc("/api/topology", makeTopologyList(c))
-	get.HandleFunc("/api/topology/{topology}", captureTopology(c, handleTopology))
-	get.HandleFunc("/api/topology/{topology}/ws", captureTopology(c, handleWs))
-	get.MatcherFunc(URLMatcher("/api/topology/{topology}/{id}")).HandlerFunc(captureTopology(c, handleNode))
-	get.MatcherFunc(URLMatcher("/api/topology/{topology}/{local}/{remote}")).HandlerFunc(captureTopology(c, handleEdge))
-	get.MatcherFunc(URLMatcher("/api/origin/host/{id}")).HandlerFunc(makeOriginHostHandler(c))
-	get.HandleFunc("/api/report", makeRawReportHandler(c))
+	get.HandleFunc("/api", gzipHandler(apiHandler))
+	get.HandleFunc("/api/topology", gzipHandler(makeTopologyList(c)))
+	get.HandleFunc("/api/topology/{topology}", gzipHandler(captureTopology(c, handleTopology)))
+	get.HandleFunc("/api/topology/{topology}/ws", captureTopology(c, handleWs)) // NB not gzip!
+	get.MatcherFunc(URLMatcher("/api/topology/{topology}/{id}")).HandlerFunc(gzipHandler(captureTopology(c, handleNode)))
+	get.MatcherFunc(URLMatcher("/api/topology/{topology}/{local}/{remote}")).HandlerFunc(gzipHandler(captureTopology(c, handleEdge)))
+	get.MatcherFunc(URLMatcher("/api/origin/host/{id}")).HandlerFunc(gzipHandler(makeOriginHostHandler(c)))
+	get.HandleFunc("/api/report", gzipHandler(makeRawReportHandler(c)))
 	get.PathPrefix("/").Handler(http.FileServer(FS(false))) // everything else is static
+
 	return router
 }
 
 func makeReportPostHandler(a xfer.Adder) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		var rpt report.Report
-		if err := gob.NewDecoder(r.Body).Decode(&rpt); err != nil {
+
+		var reader io.ReadCloser
+		defer func() { reader.Close() }()
+
+		reader = r.Body
+		var err error
+		if strings.Contains(r.Header.Get("Content-Encoding"), "gzip") {
+			reader, err = gzip.NewReader(r.Body)
+			if err != nil {
+				http.Error(w, err.Error(), http.StatusBadRequest)
+				return
+			}
+		}
+
+		if err := gob.NewDecoder(reader).Decode(&rpt); err != nil {
 			http.Error(w, err.Error(), http.StatusBadRequest)
 			return
 		}