Beispiel #1
0
func (r *ProxyHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	proxyHandlerTraceID := rand.Int63()

	var verb string
	var apiResource string
	var httpCode int
	reqStart := time.Now()
	defer metrics.Monitor(&verb, &apiResource, net.GetHTTPClient(req), w.Header().Get("Content-Type"), httpCode, reqStart)

	requestInfo, err := r.requestInfoResolver.GetRequestInfo(req)
	if err != nil || !requestInfo.IsResourceRequest {
		notFound(w, req)
		httpCode = http.StatusNotFound
		return
	}
	verb = requestInfo.Verb
	namespace, resource, parts := requestInfo.Namespace, requestInfo.Resource, requestInfo.Parts

	ctx, ok := r.context.Get(req)
	if !ok {
		ctx = api.NewContext()
	}
	ctx = api.WithNamespace(ctx, namespace)
	if len(parts) < 2 {
		notFound(w, req)
		httpCode = http.StatusNotFound
		return
	}
	id := parts[1]
	remainder := ""
	if len(parts) > 2 {
		proxyParts := parts[2:]
		remainder = strings.Join(proxyParts, "/")
		if strings.HasSuffix(req.URL.Path, "/") {
			// The original path had a trailing slash, which has been stripped
			// by KindAndNamespace(). We should add it back because some
			// servers (like etcd) require it.
			remainder = remainder + "/"
		}
	}
	storage, ok := r.storage[resource]
	if !ok {
		httplog.LogOf(req, w).Addf("'%v' has no storage object", resource)
		notFound(w, req)
		httpCode = http.StatusNotFound
		return
	}
	apiResource = resource

	gv := unversioned.GroupVersion{Group: requestInfo.APIGroup, Version: requestInfo.APIVersion}

	redirector, ok := storage.(rest.Redirector)
	if !ok {
		httplog.LogOf(req, w).Addf("'%v' is not a redirector", resource)
		httpCode = errorNegotiated(errors.NewMethodNotSupported(api.Resource(resource), "proxy"), r.serializer, gv, w, req)
		return
	}

	location, roundTripper, err := redirector.ResourceLocation(ctx, id)
	if err != nil {
		httplog.LogOf(req, w).Addf("Error getting ResourceLocation: %v", err)
		httpCode = errorNegotiated(err, r.serializer, gv, w, req)
		return
	}
	if location == nil {
		httplog.LogOf(req, w).Addf("ResourceLocation for %v returned nil", id)
		notFound(w, req)
		httpCode = http.StatusNotFound
		return
	}

	if roundTripper != nil {
		glog.V(5).Infof("[%x: %v] using transport %T...", proxyHandlerTraceID, req.URL, roundTripper)
	}

	// Default to http
	if location.Scheme == "" {
		location.Scheme = "http"
	}
	// Add the subpath
	if len(remainder) > 0 {
		location.Path = singleJoiningSlash(location.Path, remainder)
	}
	// Start with anything returned from the storage, and add the original request's parameters
	values := location.Query()
	for k, vs := range req.URL.Query() {
		for _, v := range vs {
			values.Add(k, v)
		}
	}
	location.RawQuery = values.Encode()

	newReq, err := http.NewRequest(req.Method, location.String(), req.Body)
	if err != nil {
		httpCode = errorNegotiated(err, r.serializer, gv, w, req)
		return
	}
	httpCode = http.StatusOK
	newReq.Header = req.Header
	newReq.ContentLength = req.ContentLength
	// Copy the TransferEncoding is for future-proofing. Currently Go only supports "chunked" and
	// it can determine the TransferEncoding based on ContentLength and the Body.
	newReq.TransferEncoding = req.TransferEncoding

	// TODO convert this entire proxy to an UpgradeAwareProxy similar to
	// https://github.com/openshift/origin/blob/master/pkg/util/httpproxy/upgradeawareproxy.go.
	// That proxy needs to be modified to support multiple backends, not just 1.
	if r.tryUpgrade(w, req, newReq, location, roundTripper, gv) {
		return
	}

	// Redirect requests of the form "/{resource}/{name}" to "/{resource}/{name}/"
	// This is essentially a hack for http://issue.k8s.io/4958.
	// Note: Keep this code after tryUpgrade to not break that flow.
	if len(parts) == 2 && !strings.HasSuffix(req.URL.Path, "/") {
		var queryPart string
		if len(req.URL.RawQuery) > 0 {
			queryPart = "?" + req.URL.RawQuery
		}
		w.Header().Set("Location", req.URL.Path+"/"+queryPart)
		w.WriteHeader(http.StatusMovedPermanently)
		return
	}

	start := time.Now()
	glog.V(4).Infof("[%x] Beginning proxy %s...", proxyHandlerTraceID, req.URL)
	defer func() {
		glog.V(4).Infof("[%x] Proxy %v finished %v.", proxyHandlerTraceID, req.URL, time.Now().Sub(start))
	}()

	proxy := httputil.NewSingleHostReverseProxy(&url.URL{Scheme: location.Scheme, Host: location.Host})
	alreadyRewriting := false
	if roundTripper != nil {
		_, alreadyRewriting = roundTripper.(*proxyutil.Transport)
		glog.V(5).Infof("[%x] Not making a reriting transport for proxy %s...", proxyHandlerTraceID, req.URL)
	}
	if !alreadyRewriting {
		glog.V(5).Infof("[%x] making a transport for proxy %s...", proxyHandlerTraceID, req.URL)
		prepend := path.Join(r.prefix, resource, id)
		if len(namespace) > 0 {
			prepend = path.Join(r.prefix, "namespaces", namespace, resource, id)
		}
		pTransport := &proxyutil.Transport{
			Scheme:       req.URL.Scheme,
			Host:         req.URL.Host,
			PathPrepend:  prepend,
			RoundTripper: roundTripper,
		}
		roundTripper = pTransport
	}
	proxy.Transport = roundTripper
	proxy.FlushInterval = 200 * time.Millisecond
	proxy.ServeHTTP(w, newReq)
}
Beispiel #2
0
func WithImpersonation(handler http.Handler, requestContextMapper api.RequestContextMapper, a authorizer.Authorizer) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		requestedSubject := req.Header.Get("Impersonate-User")
		if len(requestedSubject) == 0 {
			handler.ServeHTTP(w, req)
			return
		}

		ctx, exists := requestContextMapper.Get(req)
		if !exists {
			forbidden(w, req)
			return
		}
		requestor, exists := api.UserFrom(ctx)
		if !exists {
			forbidden(w, req)
			return
		}

		actingAsAttributes := &authorizer.AttributesRecord{
			User:            requestor,
			Verb:            "impersonate",
			APIGroup:        api.GroupName,
			Resource:        "users",
			Name:            requestedSubject,
			ResourceRequest: true,
		}
		if namespace, name, err := serviceaccount.SplitUsername(requestedSubject); err == nil {
			actingAsAttributes.Resource = "serviceaccounts"
			actingAsAttributes.Namespace = namespace
			actingAsAttributes.Name = name
		}

		err := a.Authorize(actingAsAttributes)
		if err != nil {
			forbidden(w, req)
			return
		}

		switch {
		case strings.HasPrefix(requestedSubject, serviceaccount.ServiceAccountUsernamePrefix):
			namespace, name, err := serviceaccount.SplitUsername(requestedSubject)
			if err != nil {
				forbidden(w, req)
				return
			}
			requestContextMapper.Update(req, api.WithUser(ctx, serviceaccount.UserInfo(namespace, name, "")))

		default:
			newUser := &user.DefaultInfo{
				Name: requestedSubject,
			}
			requestContextMapper.Update(req, api.WithUser(ctx, newUser))
		}

		newCtx, _ := requestContextMapper.Get(req)
		oldUser, _ := api.UserFrom(ctx)
		newUser, _ := api.UserFrom(newCtx)
		httplog.LogOf(req, w).Addf("%v is acting as %v", oldUser, newUser)

		handler.ServeHTTP(w, req)
	})
}