internal/middleware: move the timeout middleware to its own package

This removes the direct dependency from cmd/pkgsite to the middleware
package. The middleware package has a lot of dependencies but most
middlewares are not used by cmd/pkgsite.

There are still some middlewares used by internal/frontend so the
indirect dependency still exists.

For #61399

Change-Id: I09eee46b2ff13e112d24df62073074eb5aa3e901
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/511315
Run-TryBot: Michael Matloob <matloob@golang.org>
Reviewed-by: Jamal Carvalho <jamal@golang.org>
kokoro-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

cmd/frontend/main.go

@@ -24,6 +24,7 @@ import (
  "golang.org/x/pkgsite/internal/frontend"
  "golang.org/x/pkgsite/internal/log"
  "golang.org/x/pkgsite/internal/middleware"
+ "golang.org/x/pkgsite/internal/middleware/timeout"
  "golang.org/x/pkgsite/internal/postgres"
  "golang.org/x/pkgsite/internal/proxy"
  "golang.org/x/pkgsite/internal/queue"
@@ -188,7 +189,7 @@ func main() {
  middleware.Experiment(experimenter),
  middleware.Panic(panicHandler),
  ermw,
- middleware.Timeout(54*time.Second),
+ timeout.Timeout(54*time.Second),
  )
  addr := cfg.HostAddr(*hostAddr)
  log.Infof(ctx, "Listening on addr %s", addr)

cmd/pkgsite/main.go

@@ -72,7 +72,7 @@ import (
  "golang.org/x/pkgsite/internal/fetchdatasource"
  "golang.org/x/pkgsite/internal/frontend"
  "golang.org/x/pkgsite/internal/log"
- "golang.org/x/pkgsite/internal/middleware"
+ "golang.org/x/pkgsite/internal/middleware/timeout"
  "golang.org/x/pkgsite/internal/proxy"
  "golang.org/x/pkgsite/internal/source"
  "golang.org/x/pkgsite/internal/stdlib"
@@ -170,7 +170,7 @@ func main() {
 
  router := http.NewServeMux()
  server.Install(router.Handle, nil, nil)
- mw := middleware.Timeout(54 * time.Second)
+ mw := timeout.Timeout(54 * time.Second)
  srv := &http.Server{Addr: addr, Handler: mw(router)}
  die("%v", srv.Serve(ln))
 }

cmd/worker/main.go

@@ -23,6 +23,7 @@ import (
  "golang.org/x/pkgsite/internal/index"
  "golang.org/x/pkgsite/internal/log"
  "golang.org/x/pkgsite/internal/middleware"
+ mtimeout "golang.org/x/pkgsite/internal/middleware/timeout"
  "golang.org/x/pkgsite/internal/proxy"
  "golang.org/x/pkgsite/internal/queue/gcpqueue"
  "golang.org/x/pkgsite/internal/source"
@@ -142,7 +143,7 @@ func main() {
 
  mw := middleware.Chain(
  middleware.RequestLog(cmdconfig.Logger(ctx, cfg, "worker-log")),
- middleware.Timeout(time.Duration(timeout)*time.Minute),
+ mtimeout.Timeout(time.Duration(timeout)*time.Minute),
  iap,
  middleware.Experiment(experimenter),
  )

internal/middleware/timeout.go → internal/middleware/timeout/timeout.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 middleware
+package timeout
 
 import (
  "context"
@@ -12,7 +12,7 @@ import (
 
 // Timeout returns a new Middleware that times out each request after the given
 // duration.
-func Timeout(d time.Duration) Middleware {
+func Timeout(d time.Duration) func(http.Handler) http.Handler {
  return func(h http.Handler) http.Handler {
  return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
  ctx, cancel := context.WithTimeout(r.Context(), d)

internal/middleware/timeout_test.go → internal/middleware/timeout/timeout_test.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 middleware
+package timeout
 
 import (
  "fmt"