1 files changed, 215 insertions, 0 deletions
diff --git a/website/cmd/server/main.go b/website/cmd/server/main.go
new file mode 100644
index 000000000..c401b6abd
--- /dev/null
+++ b/website/cmd/server/main.go
@@ -0,0 +1,215 @@
+// Copyright 2019 The gVisor Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Server is the main gvisor.dev binary.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"regexp"
+	"strings"
+)
+
+var redirects = map[string]string{
+	// GitHub redirects.
+	"/change":    "https://github.com/google/gvisor",
+	"/issue":     "https://github.com/google/gvisor/issues",
+	"/issue/new": "https://github.com/google/gvisor/issues/new",
+	"/pr":        "https://github.com/google/gvisor/pulls",
+
+	// For links.
+	"/faq": "/docs/user_guide/faq/",
+
+	// From 2020-05-12 to 2020-06-30, the FAQ URL was uppercase. Redirect that
+	// back to maintain any links.
+	"/docs/user_guide/FAQ/": "/docs/user_guide/faq/",
+
+	// Redirects to compatibility docs.
+	"/c":             "/docs/user_guide/compatibility/",
+	"/c/linux/amd64": "/docs/user_guide/compatibility/linux/amd64/",
+
+	// Redirect for old URLs.
+	"/docs/user_guide/compatibility/amd64/": "/docs/user_guide/compatibility/linux/amd64/",
+	"/docs/user_guide/compatibility/amd64":  "/docs/user_guide/compatibility/linux/amd64/",
+	"/docs/user_guide/kubernetes/":          "/docs/user_guide/quick_start/kubernetes/",
+	"/docs/user_guide/kubernetes":           "/docs/user_guide/quick_start/kubernetes/",
+	"/docs/user_guide/oci/":                 "/docs/user_guide/quick_start/oci/",
+	"/docs/user_guide/oci":                  "/docs/user_guide/quick_start/oci/",
+	"/docs/user_guide/docker/":              "/docs/user_guide/quick_start/docker/",
+	"/docs/user_guide/docker":               "/docs/user_guide/quick_start/docker/",
+
+	// Deprecated, but links continue to work.
+	"/cl": "https://gvisor-review.googlesource.com",
+}
+
+var prefixHelpers = map[string]string{
+	"change": "https://github.com/google/gvisor/commit/%s",
+	"issue":  "https://github.com/google/gvisor/issues/%s",
+	"pr":     "https://github.com/google/gvisor/pull/%s",
+
+	// Redirects to compatibility docs.
+	"c/linux/amd64": "/docs/user_guide/compatibility/linux/amd64/#%s",
+
+	// Deprecated, but links continue to work.
+	"cl": "https://gvisor-review.googlesource.com/c/gvisor/+/%s",
+}
+
+var (
+	validID    = regexp.MustCompile(`^[A-Za-z0-9-]*/?$`)
+	goGetHTML5 = `<!doctype html><html><head><meta charset=utf-8>
+<meta name="go-import" content="gvisor.dev/gvisor git https://github.com/google/gvisor">
+<meta name="go-import" content="gvisor.dev/website git https://github.com/google/gvisor-website">
+<title>Go-get</title></head><body></html>`
+)
+
+// cronHandler wraps an http.Handler to check that the request is from the App
+// Engine Cron service.
+// See: https://cloud.google.com/appengine/docs/standard/go112/scheduling-jobs-with-cron-yaml#validating_cron_requests
+func cronHandler(h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Header.Get("X-Appengine-Cron") != "true" {
+			http.NotFound(w, r)
+			return
+		}
+		// Fallthrough.
+		h.ServeHTTP(w, r)
+	})
+}
+
+// wrappedHandler wraps an http.Handler.
+//
+// If the query parameters include go-get=1, then we redirect to a single
+// static page that allows us to serve arbitrary Go packages.
+func wrappedHandler(h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gg, ok := r.URL.Query()["go-get"]
+		if ok && len(gg) == 1 && gg[0] == "1" {
+			// Serve a trivial html page.
+			w.Write([]byte(goGetHTML5))
+			return
+		}
+		// Fallthrough.
+		h.ServeHTTP(w, r)
+	})
+}
+
+// redirectWithQuery redirects to the given target url preserving query parameters.
+func redirectWithQuery(w http.ResponseWriter, r *http.Request, target string) {
+	url := target
+	if qs := r.URL.RawQuery; qs != "" {
+		url += "?" + qs
+	}
+	http.Redirect(w, r, url, http.StatusFound)
+}
+
+// hostRedirectHandler redirects the www. domain to the naked domain.
+func hostRedirectHandler(h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if strings.HasPrefix(r.Host, "www.") {
+			// Redirect to the naked domain.
+			r.URL.Scheme = "https"  // Assume https.
+			r.URL.Host = r.Host[4:] // Remove the 'www.'
+			http.Redirect(w, r, r.URL.String(), http.StatusMovedPermanently)
+			return
+		}
+
+		if *projectID != "" && r.Host == *projectID+".appspot.com" && *customHost != "" {
+			// Redirect to the custom domain.
+			r.URL.Scheme = "https" // Assume https.
+			r.URL.Host = *customHost
+			http.Redirect(w, r, r.URL.String(), http.StatusMovedPermanently)
+			return
+		}
+		h.ServeHTTP(w, r)
+	})
+}
+
+// prefixRedirectHandler returns a handler that redirects to the given formated url.
+func prefixRedirectHandler(prefix, baseURL string) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if p := r.URL.Path; p == prefix {
+			// Redirect /prefix/ to /prefix.
+			http.Redirect(w, r, p[:len(p)-1], http.StatusFound)
+			return
+		}
+		id := r.URL.Path[len(prefix):]
+		if !validID.MatchString(id) {
+			http.Error(w, "Not found", http.StatusNotFound)
+			return
+		}
+		target := fmt.Sprintf(baseURL, id)
+		redirectWithQuery(w, r, target)
+	})
+}
+
+// redirectHandler returns a handler that redirects to the given url.
+func redirectHandler(target string) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		redirectWithQuery(w, r, target)
+	})
+}
+
+// redirectRedirects registers redirect http handlers.
+func registerRedirects(mux *http.ServeMux) {
+	if mux == nil {
+		mux = http.DefaultServeMux
+	}
+
+	for prefix, baseURL := range prefixHelpers {
+		p := "/" + prefix + "/"
+		mux.Handle(p, hostRedirectHandler(wrappedHandler(prefixRedirectHandler(p, baseURL))))
+	}
+
+	for path, redirect := range redirects {
+		mux.Handle(path, hostRedirectHandler(wrappedHandler(redirectHandler(redirect))))
+	}
+}
+
+// registerStatic registers static file handlers
+func registerStatic(mux *http.ServeMux, staticDir string) {
+	if mux == nil {
+		mux = http.DefaultServeMux
+	}
+	mux.Handle("/", hostRedirectHandler(wrappedHandler(http.FileServer(http.Dir(staticDir)))))
+}
+
+func envFlagString(name, def string) string {
+	if val := os.Getenv(name); val != "" {
+		return val
+	}
+	return def
+}
+
+var (
+	addr      = flag.String("http", envFlagString("HTTP", ":"+envFlagString("PORT", "8080")), "HTTP service address")
+	staticDir = flag.String("static-dir", envFlagString("STATIC_DIR", "_site"), "static files directory")
+
+	// Uses the standard GOOGLE_CLOUD_PROJECT environment variable set by App Engine.
+	projectID  = flag.String("project-id", envFlagString("GOOGLE_CLOUD_PROJECT", ""), "The App Engine project ID.")
+	customHost = flag.String("custom-domain", envFlagString("CUSTOM_DOMAIN", "gvisor.dev"), "The application's custom domain.")
+)
+
+func main() {
+	flag.Parse()
+
+	registerRedirects(nil)
+	registerStatic(nil, *staticDir)
+
+	log.Printf("Listening on %s...", *addr)
+	log.Fatal(http.ListenAndServe(*addr, nil))
+}