web/ui: fix asset generation for Go modules installs

Signed-off-by: Simon Pasquier <spasquie@redhat.com>

web/ui/ui.go

@@ -16,8 +16,6 @@
 package ui
 
 import (
-	"go/build"
-	"log"
 	"net/http"
 	"os"
 	"strings"
@@ -26,16 +24,8 @@ import (
 	"github.com/shurcooL/httpfs/union"
 )
 
-func importPathToDir(importPath string) string {
-	p, err := build.Import(importPath, "", build.FindOnly)
-	if err != nil {
-		log.Fatalln(err)
-	}
-	return p.Dir
-}
-
 var static http.FileSystem = filter.Keep(
-	http.Dir(importPathToDir("github.com/prometheus/prometheus/web/ui/static")),
+	http.Dir("./static"),
 	func(path string, fi os.FileInfo) bool {
 		return fi.IsDir() ||
 			(!strings.HasSuffix(path, "map.js") &&
@@ -46,7 +36,7 @@ var static http.FileSystem = filter.Keep(
 )
 
 var templates http.FileSystem = filter.Keep(
-	http.Dir(importPathToDir("github.com/prometheus/prometheus/web/ui/templates")),
+	http.Dir("./templates"),
 	func(path string, fi os.FileInfo) bool {
 		return fi.IsDir() || strings.HasSuffix(path, ".html")
 	},