update

cmd/dkvsrv/main.go

@@ -3,7 +3,6 @@ package main
 import (
 	"encoding/json"
 	"fmt"
-	"github.com/flipkart-incubator/dkv/meta"
 	"io"
 	"io/ioutil"
 	"log"
@@ -16,12 +15,14 @@ import (
 	"strings"
 	"syscall"
 
+	"github.com/flipkart-incubator/dkv/internal"
+	"github.com/flipkart-incubator/dkv/meta"
+
 	"github.com/gorilla/mux"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"gopkg.in/ini.v1"
 
-	"github.com/flipkart-incubator/dkv/internal"
 	"github.com/flipkart-incubator/dkv/internal/discovery"
 	"github.com/flipkart-incubator/dkv/internal/master"
 	"github.com/flipkart-incubator/dkv/internal/opts"
@@ -525,7 +526,7 @@ func setupHttpServer() {
 	//Admin UI
 	liveMode := meta.Release == "Development"
 	fileSystem := internal.GetWWWFileSystem(liveMode)
-	router.PathPrefix("/admin/").Handler(http.StripPrefix("/admin/", http.FileServer(fileSystem)))
+	router.PathPrefix("/admin/").Handler(http.StripPrefix("/admin/", internal.NoCache(http.FileServer(fileSystem))))
 
 	http.Handle("/", router)
 	http.ListenAndServe(config.HttpListenAddr, nil)

internal/www.go

@@ -9,6 +9,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"time"
 )
 
 //go:embed www
@@ -47,3 +48,41 @@ func GetWWWFileSystem(develMode bool) http.FileSystem {
 
 	return http.FS(fSys)
 }
+
+var epoch = time.Unix(0, 0).Format(time.RFC1123)
+
+var noCacheHeaders = map[string]string{
+	"Expires":         epoch,
+	"Cache-Control":   "no-cache, private, max-age=0",
+	"Pragma":          "no-cache",
+	"X-Accel-Expires": "0",
+}
+
+var etagHeaders = []string{
+	"ETag",
+	"If-Modified-Since",
+	"If-Match",
+	"If-None-Match",
+	"If-Range",
+	"If-Unmodified-Since",
+}
+
+func NoCache(h http.Handler) http.Handler {
+	fn := func(w http.ResponseWriter, r *http.Request) {
+		// Delete any ETag headers that may have been set
+		for _, v := range etagHeaders {
+			if r.Header.Get(v) != "" {
+				r.Header.Del(v)
+			}
+		}
+
+		// Set our NoCache headers
+		for k, v := range noCacheHeaders {
+			w.Header().Set(k, v)
+		}
+
+		h.ServeHTTP(w, r)
+	}
+
+	return http.HandlerFunc(fn)
+}