_content: create explicit lib/godoc tree

For historical reasons, files in _content/, like _content/play.js,
were served as https://golang.org/lib/godoc/play.js.
Remove some complex setup by moving them to names that
match the actual serving location, such as _content/lib/godoc/play.js.

Change-Id: Ib92c3db7566b24da40e803781aca590f6bc22c8b
Reviewed-on: https://go-review.googlesource.com/c/website/+/293414
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

cmd/golangorg/local.go

@@ -27,7 +27,7 @@ func earlySetup() {
 		os.Exit(2)
 	}
 	dir := filepath.Join(file, "../../../_content")
-	if _, err := os.Stat(filepath.Join(dir, "godoc.html")); err != nil {
+	if _, err := os.Stat(filepath.Join(dir, "lib/godoc/godoc.html")); err != nil {
 		log.Printf("warning: cannot find template dir; using embedded copy")
 		return
 	}

cmd/golangorg/main.go

@@ -26,7 +26,6 @@ import (
 	"log"
 	"net/http"
 	"os"
-	"path/filepath"
 	"regexp"
 	"runtime"
 
@@ -84,21 +83,14 @@ func main() {
 	rootfs := gatefs.New(vfs.OS(*goroot), fsGate)
 	fs.Bind("/", rootfs, "/", vfs.BindReplace)
 
-	// Try serving files in /doc from a local copy before trying the main
+	// Try serving files from _content before trying the main
 	// go repository. This lets us update some documentation outside the
 	// Go release cycle. This includes root.html, which redirects to "/".
 	// See golang.org/issue/29206.
 	if *templateDir != "" {
-		fs.Bind("/doc", vfs.OS(*templateDir), "/doc", vfs.BindBefore)
-		fs.Bind("/lib/godoc", vfs.OS(*templateDir), "/", vfs.BindBefore)
-		root := filepath.Join(*templateDir, "..")
-		fs.Bind("/robots.txt", vfs.OS(root), "/robots.txt", vfs.BindBefore)
-		fs.Bind("/favicon.ico", vfs.OS(root), "/favicon.ico", vfs.BindBefore)
+		fs.Bind("/", vfs.OS(*templateDir), "/", vfs.BindBefore)
 	} else {
-		fs.Bind("/doc", vfs.FromFS(website.Content), "/doc", vfs.BindBefore)
-		fs.Bind("/lib/godoc", vfs.FromFS(website.Content), "/", vfs.BindReplace)
-		fs.Bind("/robots.txt", vfs.FromFS(website.Root), "/robots.txt", vfs.BindBefore)
-		fs.Bind("/favicon.ico", vfs.FromFS(website.Root), "/favicon.ico", vfs.BindBefore)
+		fs.Bind("/", vfs.FromFS(website.Content), "/", vfs.BindBefore)
 	}
 
 	corpus := godoc.NewCorpus(fs)

cmd/golangorg/release_test.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.16
 // +build go1.16
 
 package main
@@ -27,8 +28,7 @@ func TestReleaseHistory(t *testing.T) {
 	origFS, origPres := fs, pres
 	defer func() { fs, pres = origFS, origPres }()
 	fs = vfs.NameSpace{}
-	fs.Bind("/doc", vfs.FromFS(website.Content), "/doc", vfs.BindBefore)
-	fs.Bind("/lib/godoc", vfs.FromFS(website.Content), "/", vfs.BindReplace)
+	fs.Bind("/", vfs.FromFS(website.Content), "/", vfs.BindReplace)
 	pres = godoc.NewPresentation(godoc.NewCorpus(fs))
 	readTemplates(pres)
 	mux := registerHandlers(pres)

content.go

@@ -26,7 +26,3 @@ func subdir(fsys fs.FS, path string) fs.FS {
 	}
 	return s
 }
-
-// Root is the website root files: favicon.ico and robots.txt.
-//go:embed favicon.ico robots.txt
-var Root embed.FS