added load balance support and verbose level

src/go-proxy/http_route.go

@@ -0,0 +1,160 @@
+package main
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"strings"
+	"time"
+
+	"github.com/golang/glog"
+)
+
+type HTTPRoute struct {
+	Url      *url.URL
+	Path     string
+	PathMode string
+	Proxy    *httputil.ReverseProxy
+}
+
+func isValidProxyPathMode(mode string) bool {
+	switch mode {
+	case ProxyPathMode_Forward, ProxyPathMode_Sub, ProxyPathMode_RemovedPath:
+		return true
+	default:
+		return false
+	}
+}
+
+func NewHTTPRoute(config *ProxyConfig) (*HTTPRoute, error) {
+	url, err := url.Parse(fmt.Sprintf("%s://%s:%s", config.Scheme, config.Host, config.Port))
+	if err != nil {
+		glog.Infoln(err)
+		return nil, err
+	}
+
+	proxy := httputil.NewSingleHostReverseProxy(url)
+	proxy.Transport = transport
+
+	if !isValidProxyPathMode(config.PathMode) {
+		return nil, fmt.Errorf("invalid path mode: %s", config.PathMode)
+	}
+
+	route := &HTTPRoute{
+		Url:      url,
+		Path:     config.Path,
+		Proxy:    proxy,
+		PathMode: config.PathMode,
+	}
+
+	proxy.Director = nil
+
+	initRewrite := func(pr *httputil.ProxyRequest) {
+		pr.SetURL(url)
+		pr.SetXForwarded()
+	}
+	rewrite := initRewrite
+
+	switch {
+	case config.Path == "", config.PathMode == ProxyPathMode_Forward:
+		break
+	case config.PathMode == ProxyPathMode_Sub:
+		rewrite = func(pr *httputil.ProxyRequest) {
+			initRewrite(pr)
+			// disable compression
+			pr.Out.Header.Set("Accept-Encoding", "identity")
+			pr.Out.URL.Path = strings.TrimPrefix(pr.Out.URL.Path, config.Path)
+		}
+		route.Proxy.ModifyResponse = func(r *http.Response) error {
+			contentType, ok := r.Header["Content-Type"]
+			if !ok || len(contentType) == 0 {
+				glog.Infof("unknown content type for %s", r.Request.URL.String())
+				return nil
+			}
+			if !strings.HasPrefix(contentType[0], "text/html") {
+				return nil
+			}
+			err := utils.respRemovePath(r, config.Path)
+			if err != nil {
+				err = fmt.Errorf("failed to remove path prefix %s: %v", config.Path, err)
+				r.Status = err.Error()
+				r.StatusCode = http.StatusInternalServerError
+			}
+			return err
+		}
+	default:
+		rewrite = func(pr *httputil.ProxyRequest) {
+			initRewrite(pr)
+			pr.Out.URL.Path = strings.TrimPrefix(pr.Out.URL.Path, config.Path)
+		}
+	}
+
+	if glog.V(3) {
+		route.Proxy.Rewrite = func(pr *httputil.ProxyRequest) {
+			rewrite(pr)
+			r := pr.In
+			glog.Infof("[Request] %s %s%s", r.Method, r.Host, r.URL.Path)
+			glog.V(4).InfoDepthf(1, "Headers: %v", r.Header)
+		}
+	} else {
+		route.Proxy.Rewrite = rewrite
+	}
+
+	return route, nil
+}
+
+func (p *httpLoadBalancePool) Pick() *HTTPRoute {
+	// round-robin
+	index := int(p.curentIndex.Load())
+	defer p.curentIndex.Add(1)
+	return p.pool[index%len(p.pool)]
+}
+
+func redirectToTLS(w http.ResponseWriter, r *http.Request) {
+	// Redirect to the same host but with HTTPS
+	var redirectCode int
+	if r.Method == http.MethodGet {
+		redirectCode = http.StatusMovedPermanently
+	} else {
+		redirectCode = http.StatusPermanentRedirect
+	}
+	http.Redirect(w, r, fmt.Sprintf("https://%s%s?%s", r.Host, r.URL.Path, r.URL.RawQuery), redirectCode)
+}
+
+func findHTTPRoute(host string, path string) (*HTTPRoute, error) {
+	subdomain := strings.Split(host, ".")[0]
+	routeMap, ok := routes.HTTPRoutes.UnsafeGet(subdomain)
+	if !ok {
+		return nil, fmt.Errorf("no matching route for subdomain %s", subdomain)
+	}
+	return routeMap.FindMatch(path)
+}
+
+func httpProxyHandler(w http.ResponseWriter, r *http.Request) {
+	route, err := findHTTPRoute(r.Host, r.URL.Path)
+	if err != nil {
+		err = fmt.Errorf("[Request] failed %s %s%s, error: %v",
+			r.Method,
+			r.Host,
+			r.URL.Path,
+			err,
+		)
+		glog.Error(err)
+		http.Error(w, err.Error(), http.StatusNotFound)
+		return
+	}
+	route.Proxy.ServeHTTP(w, r)
+}
+
+// TODO: default + per proxy
+var transport = &http.Transport{
+	Proxy: http.ProxyFromEnvironment,
+	DialContext: (&net.Dialer{
+		Timeout:   60 * time.Second,
+		KeepAlive: 60 * time.Second,
+	}).DialContext,
+	MaxIdleConns:        1000,
+	MaxIdleConnsPerHost: 1000,
+}