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_content/tour: fix links, fix CSP policy for tour
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Some links were missing the /tour/ at the front.

The tour also has links like <a href="javascript:next()">, which require
us to set unsafe-inline (or else enumerate the SHA256 of every link)
in the CSP header.

Also make the local server a bit more tour-friendly.

Fixes golang/go#49880.

Change-Id: Ice746571db1a34e1c02b4b2a16c4e9f30dc164d1
Reviewed-on: https://go-review.googlesource.com/c/website/+/368034
Trust: Russ Cox <[email protected]>
Run-TryBot: Russ Cox <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Jamal Carvalho <[email protected]>
Website-Publish: Russ Cox <[email protected]>
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4 changes: 2 additions & 2 deletions _content/tour/basics.article
Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,7 @@ By convention, the package name is the same as the last element of the import pa
#appengine: deterministic, so each time you run the example program
#appengine: `rand.Intn` will return the same number.
#appengine:
#appengine: (To see a different number, seed the number generator; see [[https://golang.org/pkg/math/rand/#Seed][`rand.Seed`]].
#appengine: (To see a different number, seed the number generator; see [[/pkg/math/rand/#Seed][`rand.Seed`]].
#appengine: Time is constant in the playground, so you will need to use something else as the seed.)

.play basics/packages.go
Expand Down Expand Up @@ -232,4 +232,4 @@ Try printing `needInt(Big)` too.

You finished this lesson!

You can go back to the list of [[/list][modules]] to find what to learn next, or continue with the [[javascript:click('.next-page')][next lesson]].
You can go back to the list of [[/tour/list][modules]] to find what to learn next, or continue with the [[javascript:click('.next-page')][next lesson]].
22 changes: 11 additions & 11 deletions _content/tour/concurrency.article
Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,7 @@ starts a new goroutine running

The evaluation of `f`, `x`, `y`, and `z` happens in the current goroutine and the execution of `f` happens in the new goroutine.

Goroutines run in the same address space, so access to shared memory must be synchronized. The [[https://golang.org/pkg/sync/][`sync`]] package provides useful primitives, although you won't need them much in Go as there are other primitives. (See the next slide.)
Goroutines run in the same address space, so access to shared memory must be synchronized. The [[/pkg/sync/][`sync`]] package provides useful primitives, although you won't need them much in Go as there are other primitives. (See the next slide.)

.play concurrency/goroutines.go

Expand Down Expand Up @@ -145,7 +145,7 @@ one goroutine can access a variable at a time to avoid conflicts?
This concept is called _mutual_exclusion_, and the conventional name for the data structure that provides it is _mutex_.

Go's standard library provides mutual exclusion with
[[https://golang.org/pkg/sync/#Mutex][`sync.Mutex`]] and its two methods:
[[/pkg/sync/#Mutex][`sync.Mutex`]] and its two methods:

- `Lock`
- `Unlock`
Expand All @@ -171,18 +171,18 @@ safe for concurrent use!
* Where to Go from here...

#appengine: You can get started by
#appengine: [[https://golang.org/dl/][installing Go]].
#appengine: [[/dl/][installing Go]].

#appengine: Once you have Go installed, the
The
[[https://golang.org/doc/][Go Documentation]] is a great place to
[[/doc/][Go Documentation]] is a great place to
#appengine: continue.
start.
It contains references, tutorials, videos, and more.

To learn how to organize and work with Go code, read [[https://golang.org/doc/code][How to Write Go Code]].
To learn how to organize and work with Go code, read [[/doc/code][How to Write Go Code]].

If you need help with the standard library, see the [[https://golang.org/pkg/][package reference]]. For help with the language itself, you might be surprised to find the [[https://golang.org/ref/spec][Language Spec]] is quite readable.
If you need help with the standard library, see the [[/pkg/][package reference]]. For help with the language itself, you might be surprised to find the [[/ref/spec][Language Spec]] is quite readable.

To further explore Go's concurrency model, watch
[[https://www.youtube.com/watch?v=f6kdp27TYZs][Go Concurrency Patterns]]
Expand All @@ -191,18 +191,18 @@ and
[[https://www.youtube.com/watch?v=QDDwwePbDtw][Advanced Go Concurrency Patterns]]
([[https://go.dev/talks/2013/advconc.slide][slides]])
and read the
[[https://golang.org/doc/codewalk/sharemem/][Share Memory by Communicating]]
[[/doc/codewalk/sharemem/][Share Memory by Communicating]]
codewalk.

To get started writing web applications, watch
[[https://vimeo.com/53221558][A simple programming environment]]
([[https://go.dev/talks/2012/simple.slide][slides]])
and read the
[[https://golang.org/doc/articles/wiki/][Writing Web Applications]] tutorial.
[[/doc/articles/wiki/][Writing Web Applications]] tutorial.

The [[https://golang.org/doc/codewalk/functions/][First Class Functions in Go]] codewalk gives an interesting perspective on Go's function types.
The [[/doc/codewalk/functions/][First Class Functions in Go]] codewalk gives an interesting perspective on Go's function types.

The [[https://blog.golang.org/][Go Blog]] has a large archive of informative Go articles.
The [[/blog/][Go Blog]] has a large archive of informative Go articles.

Visit [[https://golang.org][golang.org]] for more.
Visit [[/][the Go home page]] for more.

6 changes: 3 additions & 3 deletions _content/tour/flowcontrol.article
Original file line number Diff line number Diff line change
Expand Up @@ -100,7 +100,7 @@ Next, change the loop condition to stop once the value has stopped
changing (or only changes by a very small amount).
See if that's more or fewer than 10 iterations.
Try other initial guesses for z, like x, or x/2.
How close are your function's results to the [[https://golang.org/pkg/math/#Sqrt][math.Sqrt]] in the standard library?
How close are your function's results to the [[/pkg/math/#Sqrt][math.Sqrt]] in the standard library?

(*Note:* If you are interested in the details of the algorithm, the z² − x above
is how far away z² is from where it needs to be (x), and the division by 2z is the derivative
Expand Down Expand Up @@ -167,12 +167,12 @@ Deferred function calls are pushed onto a stack. When a function returns, its
deferred calls are executed in last-in-first-out order.

To learn more about defer statements read this
[[https://blog.golang.org/defer-panic-and-recover][blog post]].
[[/blog/defer-panic-and-recover][blog post]].

.play flowcontrol/defer-multi.go

* Congratulations!

You finished this lesson!

You can go back to the list of [[/list][modules]] to find what to learn next, or continue with the [[javascript:click('.next-page')][next lesson]].
You can go back to the list of [[/tour/list][modules]] to find what to learn next, or continue with the [[javascript:click('.next-page')][next lesson]].
24 changes: 12 additions & 12 deletions _content/tour/methods.article
Original file line number Diff line number Diff line change
Expand Up @@ -269,7 +269,7 @@ of the same interface type and value as `i`.

* Stringers

One of the most ubiquitous interfaces is [[//golang.org/pkg/fmt/#Stringer][`Stringer`]] defined by the [[//golang.org/pkg/fmt/][`fmt`]] package.
One of the most ubiquitous interfaces is [[/pkg/fmt/#Stringer][`Stringer`]] defined by the [[/pkg/fmt/][`fmt`]] package.

type Stringer interface {
String() string
Expand Down Expand Up @@ -318,7 +318,7 @@ A nil `error` denotes success; a non-nil `error` denotes failure.

* Exercise: Errors

Copy your `Sqrt` function from the [[/flowcontrol/8][earlier exercise]] and modify it to return an `error` value.
Copy your `Sqrt` function from the [[/tour/flowcontrol/8][earlier exercise]] and modify it to return an `error` value.

`Sqrt` should return a non-nil error value when given a negative number, as it doesn't support complex numbers.

Expand Down Expand Up @@ -354,7 +354,7 @@ populated and an error value. It returns an `io.EOF` error when the stream
ends.

The example code creates a
[[//golang.org/pkg/strings/#Reader][`strings.Reader`]]
[[/pkg/strings/#Reader][`strings.Reader`]]
and consumes its output 8 bytes at a time.

.play methods/reader.go
Expand All @@ -368,9 +368,9 @@ Implement a `Reader` type that emits an infinite stream of the ASCII character

* Exercise: rot13Reader

A common pattern is an [[https://golang.org/pkg/io/#Reader][io.Reader]] that wraps another `io.Reader`, modifying the stream in some way.
A common pattern is an [[/pkg/io/#Reader][io.Reader]] that wraps another `io.Reader`, modifying the stream in some way.

For example, the [[https://golang.org/pkg/compress/gzip/#NewReader][gzip.NewReader]] function takes an `io.Reader` (a stream of compressed data) and returns a `*gzip.Reader` that also implements `io.Reader` (a stream of the decompressed data).
For example, the [[/pkg/compress/gzip/#NewReader][gzip.NewReader]] function takes an `io.Reader` (a stream of compressed data) and returns a `*gzip.Reader` that also implements `io.Reader` (a stream of the decompressed data).

Implement a `rot13Reader` that implements `io.Reader` and reads from an `io.Reader`, modifying the stream by applying the [[https://en.wikipedia.org/wiki/ROT13][rot13]] substitution cipher to all alphabetical characters.

Expand All @@ -381,7 +381,7 @@ Make it an `io.Reader` by implementing its `Read` method.

* Images

[[https://golang.org/pkg/image/#Image][Package image]] defines the `Image` interface:
[[/pkg/image/#Image][Package image]] defines the `Image` interface:

package image

Expand All @@ -392,20 +392,20 @@ Make it an `io.Reader` by implementing its `Read` method.
}

*Note*: the `Rectangle` return value of the `Bounds` method is actually an
[[https://golang.org/pkg/image/#Rectangle][`image.Rectangle`]], as the
[[/pkg/image/#Rectangle][`image.Rectangle`]], as the
declaration is inside package `image`.

(See [[https://golang.org/pkg/image/#Image][the documentation]] for all the details.)
(See [[/pkg/image/#Image][the documentation]] for all the details.)

The `color.Color` and `color.Model` types are also interfaces, but we'll ignore that by using the predefined implementations `color.RGBA` and `color.RGBAModel`. These interfaces and types are specified by the [[https://golang.org/pkg/image/color/][image/color package]]
The `color.Color` and `color.Model` types are also interfaces, but we'll ignore that by using the predefined implementations `color.RGBA` and `color.RGBAModel`. These interfaces and types are specified by the [[/pkg/image/color/][image/color package]]

.play methods/images.go

* Exercise: Images

Remember the [[/moretypes/18][picture generator]] you wrote earlier? Let's write another one, but this time it will return an implementation of `image.Image` instead of a slice of data.
Remember the [[/tour/moretypes/18][picture generator]] you wrote earlier? Let's write another one, but this time it will return an implementation of `image.Image` instead of a slice of data.

Define your own `Image` type, implement [[https://golang.org/pkg/image/#Image][the necessary methods]], and call `pic.ShowImage`.
Define your own `Image` type, implement [[/pkg/image/#Image][the necessary methods]], and call `pic.ShowImage`.

`Bounds` should return a `image.Rectangle`, like `image.Rect(0,`0,`w,`h)`.

Expand All @@ -419,4 +419,4 @@ Define your own `Image` type, implement [[https://golang.org/pkg/image/#Image][t

You finished this lesson!

You can go back to the list of [[/list][modules]] to find what to learn next, or continue with the [[javascript:click('.next-page')][next lesson]].
You can go back to the list of [[/tour/list][modules]] to find what to learn next, or continue with the [[javascript:click('.next-page')][next lesson]].
8 changes: 4 additions & 4 deletions _content/tour/moretypes.article
Original file line number Diff line number Diff line change
Expand Up @@ -214,7 +214,7 @@ Slices can contain any type, including other slices.
* Appending to a slice

It is common to append new elements to a slice, and so Go provides a built-in
`append` function. The [[https://golang.org/pkg/builtin/#append][documentation]]
`append` function. The [[/pkg/builtin/#append][documentation]]
of the built-in package describes `append`.

func append(s []T, vs ...T) []T
Expand All @@ -229,7 +229,7 @@ If the backing array of `s` is too small to fit all the given values a bigger
array will be allocated. The returned slice will point to the newly allocated
array.

(To learn more about slices, read the [[https://blog.golang.org/go-slices-usage-and-internals][Slices: usage and internals]] article.)
(To learn more about slices, read the [[/blog/go-slices-usage-and-internals][Slices: usage and internals]] article.)

.play moretypes/append.go

Expand Down Expand Up @@ -324,7 +324,7 @@ If `key` is not in the map, then `elem` is the zero value for the map's element

Implement `WordCount`. It should return a map of the counts of each “word” in the string `s`. The `wc.Test` function runs a test suite against the provided function and prints success or failure.

You might find [[https://golang.org/pkg/strings/#Fields][strings.Fields]] helpful.
You might find [[/pkg/strings/#Fields][strings.Fields]] helpful.

.play moretypes/exercise-maps.go

Expand Down Expand Up @@ -358,4 +358,4 @@ returns successive [[https://en.wikipedia.org/wiki/Fibonacci_number][fibonacci n

You finished this lesson!

You can go back to the list of [[/list][modules]] to find what to learn next, or continue with the [[javascript:click('.next-page')][next lesson]].
You can go back to the list of [[/tour/list][modules]] to find what to learn next, or continue with the [[javascript:click('.next-page')][next lesson]].
12 changes: 6 additions & 6 deletions _content/tour/welcome.article
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@ https://golang.org

* Hello, 世界

Welcome to a tour of the [[https://golang.org/][Go programming language]].
Welcome to a tour of the [[/][Go programming language]].

The tour is divided into a list of modules that you can
access by clicking on
Expand Down Expand Up @@ -36,7 +36,7 @@ Edit the program and run it again.

When you click on [[javascript:highlightAndClick("#format")][Format]]
(shortcut: `Ctrl` + `Enter`), the text in the editor is formatted using the
[[https://golang.org/cmd/gofmt/][gofmt]] tool. You can switch syntax highlighting on and off
[[/cmd/gofmt/][gofmt]] tool. You can switch syntax highlighting on and off
by clicking on the [[javascript:highlightAndClick(".syntax-checkbox")][syntax]] button.

When you're ready to move on, click the [[javascript:highlightAndClick(".next-page")][right arrow]] below or type the `PageDown` key.
Expand Down Expand Up @@ -68,12 +68,12 @@ Click the [[javascript:highlightAndClick(".next-page")]["next"]] button or type
#appengine: your own machine.
#appengine:
#appengine: To run the tour locally, you'll need to first
#appengine: [[https://golang.org/doc/install][install Go]] and then run:
#appengine: [[/doc/install][install Go]] and then run:
#appengine:
#appengine: go install golang.org/x/website/tour@latest
#appengine:
#appengine: This will place a `tour` binary in your
#appengine: [[https://golang.org/cmd/go/#hdr-GOPATH_and_Modules][GOPATH]]'s `bin` directory.
#appengine: [[/cmd/go/#hdr-GOPATH_and_Modules][GOPATH]]'s `bin` directory.
#appengine: When you run the tour program, it will open a web browser displaying
#appengine: your local version of the tour.
#appengine:
Expand All @@ -82,7 +82,7 @@ Click the [[javascript:highlightAndClick(".next-page")]["next"]] button or type
#appengine: * The Go Playground
#appengine:
#appengine: This tour is built atop the [[https://play.golang.org/][Go Playground]], a
#appengine: web service that runs on [[https://golang.org/][golang.org]]'s servers.
#appengine: web service that runs on [[/][golang.org]]'s servers.
#appengine:
#appengine: The service receives a Go program, compiles, links, and runs the program inside
#appengine: a sandbox, then returns the output.
Expand All @@ -95,7 +95,7 @@ Click the [[javascript:highlightAndClick(".next-page")]["next"]] button or type
#appengine:
#appengine: The playground uses the latest stable release of Go.
#appengine:
#appengine: Read "[[https://blog.golang.org/playground][Inside the Go Playground]]" to learn more.
#appengine: Read "[[/blog/playground][Inside the Go Playground]]" to learn more.
#appengine:
#appengine: .play welcome/sandbox.go

Expand Down
11 changes: 9 additions & 2 deletions cmd/golangorg/csp.go
Original file line number Diff line number Diff line change
Expand Up @@ -22,12 +22,19 @@ func buildCSP(kind string) string {
for _, k := range ks {
sb.WriteString(k)
sb.WriteString(" ")
sb.WriteString(strings.Join(csp[k], " "))
for _, v := range csp[k] {
if (kind == "tour" || kind == "talks") && strings.HasPrefix(v, "'sha256-") {
// Must drop sha256 entries to use unsafe-inline.
continue
}
sb.WriteString(v)
sb.WriteString(" ")
}
if kind == "tour" && k == "script-src" {
sb.WriteString(" ")
sb.WriteString(unsafeEval)
}
if kind == "talks" && k == "script-src" {
if (kind == "talks" || kind == "tour") && k == "script-src" {
sb.WriteString(" ")
sb.WriteString(unsafeInline)
}
Expand Down
22 changes: 16 additions & 6 deletions cmd/golangorg/server.go
Original file line number Diff line number Diff line change
Expand Up @@ -443,7 +443,13 @@ func hostPathHandler(h http.Handler) http.Handler {

elem, rest := strings.TrimPrefix(r.URL.Path, "/"), ""
if i := strings.Index(elem, "/"); i >= 0 {
elem, rest = elem[:i], elem[i+1:]
if elem[:i] == "tour" {
// The Angular router serving /tour/ fails badly when it sees /go.dev/tour/.
// Just take http://localhost/tour/ as meaning /go.dev/tour/ instead of redirecting.
elem, rest = "go.dev", elem
} else {
elem, rest = elem[:i], elem[i+1:]
}
}
if !validHosts[elem] {
u := "/go.dev" + r.URL.EscapedPath()
Expand All @@ -461,7 +467,7 @@ func hostPathHandler(h http.Handler) http.Handler {

log.Print(r.URL.String())

lw := &linkRewriter{ResponseWriter: w, host: r.Host}
lw := &linkRewriter{ResponseWriter: w, host: r.Host, tour: strings.HasPrefix(r.URL.Path, "/tour/")}
h.ServeHTTP(lw, r)
lw.Flush()
})
Expand All @@ -474,14 +480,15 @@ func hostPathHandler(h http.Handler) http.Handler {
type linkRewriter struct {
http.ResponseWriter
host string
tour bool // is this go.dev/tour/?
buf []byte
ct string // content-type
}

func (r *linkRewriter) WriteHeader(code int) {
loc := r.Header().Get("Location")
delete(r.Header(), "Content-Length") // we might change the content
if strings.HasPrefix(loc, "/") {
if strings.HasPrefix(loc, "/") && !strings.HasPrefix(loc, "/tour/") {
r.Header().Set("Location", "/"+r.host+loc)
} else if u, _ := url.Parse(loc); u != nil && validHosts[u.Host] {
r.Header().Set("Location", "/"+u.Host+"/"+strings.TrimPrefix(u.Path, "/")+u.RawQuery)
Expand All @@ -506,9 +513,12 @@ func (r *linkRewriter) Write(data []byte) (int, error) {
}

func (r *linkRewriter) Flush() {
repl := []string{
`href="/`, `href="/` + r.host + `/`,
`src="/`, `src="/` + r.host + `/`,
var repl []string
if !r.tour {
repl = []string{
`href="/`, `href="/` + r.host + `/`,
`src="/`, `src="/` + r.host + `/`,
}
}
for host := range validHosts {
repl = append(repl, `href="https://`+host, `href="/`+host)
Expand Down

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