Refactored proxy middleware

middleware/proxy/proxy.go

@@ -2,7 +2,6 @@
 package proxy
 
 import (
-	"log"
 	"net/http"
 	"net/http/httputil"
 	"net/url"
@@ -11,60 +10,75 @@ import (
 	"github.com/mholt/caddy/middleware"
 )
 
+// Proxy represents a middleware instance that can proxy requests.
+type Proxy struct {
+	Next  middleware.Handler
+	Rules []Rule
+}
+
+// ServeHTTP satisfies the middleware.Handler interface.
+func (p Proxy) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
+
+	for _, rule := range p.Rules {
+		if middleware.Path(r.URL.Path).Matches(rule.From) {
+			var base string
+
+			if strings.HasPrefix(rule.To, "http") { // includes https
+				// destination includes a scheme! no need to guess
+				base = rule.To
+			} else {
+				// no scheme specified; assume same as request
+				var scheme string
+				if r.TLS == nil {
+					scheme = "http"
+				} else {
+					scheme = "https"
+				}
+				base = scheme + "://" + rule.To
+			}
+
+			baseUrl, err := url.Parse(base)
+			if err != nil {
+				return http.StatusInternalServerError, err
+			}
+			r.Host = baseUrl.Host
+
+			// TODO: Construct this before; not during every request, if possible
+			proxy := httputil.NewSingleHostReverseProxy(baseUrl)
+			proxy.ServeHTTP(w, r)
+			return 0, nil
+		}
+	}
+
+	return p.Next.ServeHTTP(w, r)
+}
+
 // New creates a new instance of proxy middleware.
 func New(c middleware.Controller) (middleware.Middleware, error) {
-	var rules []proxyRule
+	rules, err := parse(c)
-
+	if err != nil {
-	for c.Next() {
+		return nil, err
-		rule := proxyRule{}
-
-		if !c.Args(&rule.from, &rule.to) {
-			return nil, c.ArgErr()
-		}
-
-		rules = append(rules, rule)
 	}
 
 	return func(next middleware.Handler) middleware.Handler {
-		return middleware.HandlerFunc(func(w http.ResponseWriter, r *http.Request) (int, error) {
+		return Proxy{Next: next, Rules: rules}
-
-			for _, rule := range rules {
-				if middleware.Path(r.URL.Path).Matches(rule.from) {
-					var base string
-
-					if strings.HasPrefix(rule.to, "http") { // includes https
-						// destination includes a scheme! no need to guess
-						base = rule.to
-					} else {
-						// no scheme specified; assume same as request
-						var scheme string
-						if r.TLS == nil {
-							scheme = "http"
-						} else {
-							scheme = "https"
-						}
-						base = scheme + "://" + rule.to
-					}
-
-					baseUrl, err := url.Parse(base)
-					if err != nil {
-						log.Fatal(err)
-					}
-					r.Host = baseUrl.Host
-
-					// TODO: Construct this before; not during every request, if possible
-					proxy := httputil.NewSingleHostReverseProxy(baseUrl)
-					proxy.ServeHTTP(w, r)
-					return 0, nil
-				}
-			}
-
-			return next.ServeHTTP(w, r)
-		})
 	}, nil
 }
 
-type proxyRule struct {
+func parse(c middleware.Controller) ([]Rule, error) {
-	from string
+	var rules []Rule
-	to   string
+
+	for c.Next() {
+		var rule Rule
+		if !c.Args(&rule.From, &rule.To) {
+			return rules, c.ArgErr()
+		}
+		rules = append(rules, rule)
+	}
+
+	return rules, nil
+}
+
+type Rule struct {
+	From, To string
 }

middleware/websockets/websockets.go

@@ -108,7 +108,7 @@ func New(c middleware.Controller) (middleware.Middleware, error) {
 			Path:      path,
 			Command:   cmd,
 			Arguments: args,
-			Respawn:   respawn,
+			Respawn:   respawn, // TODO: This isn't used currently
 		})
 	}