canonical host

README

@@ -43,7 +43,6 @@ gobyexample.com signups
   * return status code
   * serve static files
   * force https
-  * force canonical host
   * not found page
   * error page
 * string formatting
@@ -66,6 +65,10 @@ gobyexample.com signups
 * init functions
 * using gofmt
 * scrolls style logging
+* range and close http://tour.golang.org/#66
+* string replacement - sub & gsub
+* benchmarking
+* profiling
 
 * setting up go env, hello world
 * deploying to heroku

src/33-methods.go

@@ -33,3 +33,6 @@ func main() {
 	rectangle := Rectangle {x1: 3, x2: 10, y1: 5, y2: 7}
 	fmt.Println(rectangle.area())
 }
+
+// == todo
+// pointer vs value receivers

src/xx-http-server-canonical-host.go

@@ -0,0 +1,34 @@
+package main
+
+import ("net/http"; "fmt"; "strings")
+
+func hello(res http.ResponseWriter, req *http.Request) {
+    res.Header().Set("Content-Type", "text/plain")
+	fmt.Fprintln(res, "Hello canonical world")
+}
+
+func wrapCanonicalHost(f http.HandlerFunc, canonicalHost string) http.HandlerFunc {
+	return func(res http.ResponseWriter, req *http.Request) {
+		hostPort := strings.Split(req.Host, ":")
+		host := hostPort[0]
+		if host != canonicalHost {
+			fmt.Println("redirecting from", host, "to", canonicalHost)
+			hostPort[0] = canonicalHost
+			url := "http://" + strings.Join(hostPort, ":") + req.URL.String()
+			http.Redirect(res, req, url, 301)
+		}
+		f(res, req)
+	}
+}
+
+func main() {
+	handler := wrapCanonicalHost(hello, "localhost")
+    http.HandleFunc("/", handler)
+    http.ListenAndServe(":5000", nil)
+}
+
+// == running
+// $ go run xx-http-server-canonical-host.go
+//
+// $ curl -i -L http://127.0.0.1:5000/go
+// $ curl -i -L http://127.0.0.1:5000/go