Manage Headers for the Authentication forwarding.

middlewares/auth/forward.go

@@ -0,0 +1,97 @@
+package auth
+
+import (
+	"io/ioutil"
+	"net"
+	"net/http"
+	"strings"
+
+	"github.com/containous/traefik/log"
+	"github.com/containous/traefik/types"
+	"github.com/vulcand/oxy/forward"
+	"github.com/vulcand/oxy/utils"
+)
+
+// Forward the authentication to a external server
+func Forward(config *types.Forward, w http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+	httpClient := http.Client{}
+
+	if config.TLS != nil {
+		tlsConfig, err := config.TLS.CreateTLSConfig()
+		if err != nil {
+			log.Debugf("Impossible to configure TLS to call %s. Cause %s", config.Address, err)
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		httpClient.Transport = &http.Transport{
+			TLSClientConfig: tlsConfig,
+		}
+	}
+
+	forwardReq, err := http.NewRequest(http.MethodGet, config.Address, nil)
+	if err != nil {
+		log.Debugf("Error calling %s. Cause %s", config.Address, err)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	writeHeader(r, forwardReq, config.TrustForwardHeader)
+
+	forwardResponse, forwardErr := httpClient.Do(forwardReq)
+	if forwardErr != nil {
+		log.Debugf("Error calling %s. Cause: %s", config.Address, forwardErr)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	body, readError := ioutil.ReadAll(forwardResponse.Body)
+	if readError != nil {
+		log.Debugf("Error reading body %s. Cause: %s", config.Address, readError)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	defer forwardResponse.Body.Close()
+
+	if forwardResponse.StatusCode < http.StatusOK || forwardResponse.StatusCode >= http.StatusMultipleChoices {
+		log.Debugf("Remote error %s. StatusCode: %d", config.Address, forwardResponse.StatusCode)
+		w.WriteHeader(forwardResponse.StatusCode)
+		w.Write(body)
+		return
+	}
+
+	r.RequestURI = r.URL.RequestURI()
+	next(w, r)
+}
+
+func writeHeader(req *http.Request, forwardReq *http.Request, trustForwardHeader bool) {
+	utils.CopyHeaders(forwardReq.Header, req.Header)
+
+	if clientIP, _, err := net.SplitHostPort(req.RemoteAddr); err == nil {
+		if trustForwardHeader {
+			if prior, ok := req.Header[forward.XForwardedFor]; ok {
+				clientIP = strings.Join(prior, ", ") + ", " + clientIP
+			}
+		}
+		forwardReq.Header.Set(forward.XForwardedFor, clientIP)
+	}
+
+	if xfp := req.Header.Get(forward.XForwardedProto); xfp != "" && trustForwardHeader {
+		forwardReq.Header.Set(forward.XForwardedProto, xfp)
+	} else if req.TLS != nil {
+		forwardReq.Header.Set(forward.XForwardedProto, "https")
+	} else {
+		forwardReq.Header.Set(forward.XForwardedProto, "http")
+	}
+
+	if xfp := req.Header.Get(forward.XForwardedPort); xfp != "" && trustForwardHeader {
+		forwardReq.Header.Set(forward.XForwardedPort, xfp)
+	}
+
+	if xfh := req.Header.Get(forward.XForwardedHost); xfh != "" && trustForwardHeader {
+		forwardReq.Header.Set(forward.XForwardedHost, xfh)
+	} else if req.Host != "" {
+		forwardReq.Header.Set(forward.XForwardedHost, req.Host)
+	} else {
+		forwardReq.Header.Del(forward.XForwardedHost)
+	}
+}