tour: make the tour deployable on App Engine again

Move the main Go files into the same directory as the app.yaml file.
This changes the command location to be at golang.org/x/tour instead
of golang.org/x/tour/gotour. Add a placeholder command in gotour so
that those who use the previous installation command will know to
use the new one and it won't just seem like it has vanished.

Also update the documentation to take into account that the tour is
no longer distributed with releases as of golang.org/cl/131156

Fixes golang/go#28163

Change-Id: I60737f0cfaa93d12902a75fbc0924d96672a8c9b
Reviewed-on: https://go-review.googlesource.com/c/141857
Run-TryBot: Andrew Bonventre <andybons@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

README.md

@@ -1,16 +1,11 @@
 A Tour of Go is an introduction to the Go programming language.
 
-The easiest way to install the tour locally is to install
-[a binary release of Go](https://golang.org/dl/) and then run:
-
-	$ go tool tour
-
 To install the tour from source, first
 [set up a workspace](https://golang.org/doc/code.html) and then run:
 
-	$ go get golang.org/x/tour/gotour
+	$ go get golang.org/x/tour
 
-This will place a `gotour` binary in your workspace's `bin` directory.
+This will place a `tour` binary in your workspace's `bin` directory.
 
 Unless otherwise noted, the go-tour source files are distributed
 under the BSD-style license found in the LICENSE file.

app.yaml

@@ -1,5 +1,4 @@
-application: go-tour
-version: 1
+service: tour
 runtime: go
 api_version: go1
 
@@ -7,7 +6,7 @@ default_expiration: "7d"
 
 handlers:
 
-# Keep these static file handlers in sync with gotour/local.go.
+# Keep these static file handlers in sync with local.go.
 - url: /favicon.ico
   static_files: static/img/favicon.ico
   upload: static/img/favicon.ico

content/welcome.article

@@ -77,17 +77,10 @@ Click the [[javascript:highlightAndClick(".next-page")]["next"]] button or type
 #appengine: The stand-alone tour is faster, as it builds and runs the code samples
 #appengine: on your own machine.
 #appengine:
-#appengine: To run the tour locally first
-#appengine: [[https://golang.org/dl/][download and install Go]]
-#appengine: then start the tour from the command line:
+#appengine: To run the tour locally install and run the tour binary:
 #appengine:
-#appengine: 	go tool tour
-#appengine: 
-#appengine: Or, you can install and run this tour manually if you have any trouble
-#appengine: running the above command:
-#appengine: 
-#appengine:   go get golang.org/x/tour/gotour
-#appengine:   gotour
+#appengine:   go get golang.org/x/tour
+#appengine:   tour
 #appengine:
 #appengine: The tour program will open a web browser displaying
 #appengine: your local version of the tour.

gotour/main.go

@@ -0,0 +1,15 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"io"
+	"os"
+)
+
+func main() {
+	io.WriteString(os.Stderr, "golang.org/x/tour/gotour has moved to golang.org/x/tour\n")
+	os.Exit(1)
+}

local.go

@@ -106,7 +106,7 @@ func main() {
 	origin := &url.URL{Scheme: "http", Host: host + ":" + port}
 	http.Handle(socketPath, socket.NewHandler(origin))
 
-	// Keep these static file handlers in sync with ../app.yaml.
+	// Keep these static file handlers in sync with app.yaml.
 	static := http.FileServer(http.Dir(root))
 	http.Handle("/content/img/", static)
 	http.Handle("/static/", static)

tour.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package main // import "golang.org/x/tour/gotour"
+package main // import "golang.org/x/tour"
 
 import (
 	"bytes"