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)
}
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)
})
}
