// namespacingFilter adds a filter that adds the namespace of the request to the context. Not all requests will have namespaces,
// but any that do will have the appropriate value added.
func namespacingFilter(handler http.Handler, contextMapper kapi.RequestContextMapper) http.Handler {
infoResolver := &apiserver.RequestInfoResolver{APIPrefixes: sets.NewString("api", "osapi", "oapi", "apis"), GrouplessAPIPrefixes: sets.NewString("api", "osapi", "oapi")}
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
ctx, ok := contextMapper.Get(req)
if !ok {
http.Error(w, "Unable to find request context", http.StatusInternalServerError)
return
}
if _, exists := kapi.NamespaceFrom(ctx); !exists {
if requestInfo, err := infoResolver.GetRequestInfo(req); err == nil {
// only set the namespace if the apiRequestInfo was resolved
// keep in mind that GetAPIRequestInfo will fail on non-api requests, so don't fail the entire http request on that
// kind of failure.
// TODO reconsider special casing this. Having the special case hereallow us to fully share the kube
// APIRequestInfoResolver without any modification or customization.
namespace := requestInfo.Namespace
if (requestInfo.Resource == "projects") && (len(requestInfo.Name) > 0) {
namespace = requestInfo.Name
}
ctx = kapi.WithNamespace(ctx, namespace)
contextMapper.Update(req, ctx)
}
}
handler.ServeHTTP(w, req)
})
}
// NewRequestAuthenticator creates an http handler that tries to authenticate the given request as a user, and then
// stores any such user found onto the provided context for the request. If authentication fails or returns an error
// the failed handler is used. On success, "Authorization" header is removed from the request and handler
// is invoked to serve the request.
func NewRequestAuthenticator(mapper api.RequestContextMapper, auth authenticator.Request, failed http.Handler, handler http.Handler) (http.Handler, error) {
return api.NewRequestContextFilter(
mapper,
http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
user, ok, err := auth.AuthenticateRequest(req)
if err != nil || !ok {
if err != nil {
glog.Errorf("Unable to authenticate the request due to an error: %v", err)
}
failed.ServeHTTP(w, req)
return
}
// authorization header is not required anymore in case of a successful authentication.
req.Header.Del("Authorization")
if ctx, ok := mapper.Get(req); ok {
mapper.Update(req, api.WithUser(ctx, user))
}
authenticatedUserCounter.WithLabelValues(compressUsername(user.GetName())).Inc()
handler.ServeHTTP(w, req)
}),
)
}
// WithAuthentication creates an http handler that tries to authenticate the given request as a user, and then
// stores any such user found onto the provided context for the request. If authentication fails or returns an error
// the failed handler is used. On success, handler is invoked to serve the request.
func WithAuthentication(handler http.Handler, mapper api.RequestContextMapper, auth authenticator.Request, failed http.Handler) http.Handler {
if auth == nil {
glog.Warningf("Authentication is disabled")
return handler
}
return api.WithRequestContext(
http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
user, ok, err := auth.AuthenticateRequest(req)
if err != nil || !ok {
if err != nil {
glog.Errorf("Unable to authenticate the request due to an error: %v", err)
}
failed.ServeHTTP(w, req)
return
}
if ctx, ok := mapper.Get(req); ok {
mapper.Update(req, api.WithUser(ctx, user))
}
authenticatedUserCounter.WithLabelValues(compressUsername(user.GetName())).Inc()
handler.ServeHTTP(w, req)
}),
mapper,
)
}
func WithActingAs(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",
// ResourceName: requestedSubject,
ResourceRequest: true,
}
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)
})
}
// WithAuthorizationCheck passes all authorized requests on to handler, and returns a forbidden error otherwise.
func WithAuthorizationCheck(handler http.Handler, getAttribs RequestAttributeGetter, a authorizer.Authorizer, mapper api.RequestContextMapper) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
tenant, err := a.Authorize(getAttribs.GetAttribs(req))
if err == nil {
if ctx, ok := mapper.Get(req); ok {
mapper.Update(req, api.WithTenant(ctx, tenant))
}
handler.ServeHTTP(w, req)
return
}
forbidden(w, req)
})
}
// WithRequestInfo attaches a RequestInfo to the context.
func WithRequestInfo(handler http.Handler, resolver *request.RequestInfoResolver, requestContextMapper api.RequestContextMapper) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
ctx, ok := requestContextMapper.Get(req)
if !ok {
internalError(w, req, errors.New("no context found for request"))
return
}
info, err := resolver.GetRequestInfo(req)
if err != nil {
internalError(w, req, fmt.Errorf("failed to create RequestInfo: %v", err))
return
}
requestContextMapper.Update(req, request.WithRequestInfo(ctx, info))
handler.ServeHTTP(w, req)
})
}
// NewRequestAuthenticator creates an http handler that tries to authenticate the given request as a user, and then
// stores any such user found onto the provided context for the request. If authentication fails or returns an error
// the failed handler is used. On success, handler is invoked to serve the request.
func NewRequestAuthenticator(mapper api.RequestContextMapper, auth authenticator.Request, failed http.Handler, handler http.Handler) (http.Handler, error) {
return api.NewRequestContextFilter(
mapper,
http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
user, ok, err := auth.AuthenticateRequest(req)
if err != nil || !ok {
if err != nil {
glog.Errorf("Unable to authenticate the request due to an error: %v", err)
}
failed.ServeHTTP(w, req)
return
}
if ctx, ok := mapper.Get(req); ok {
mapper.Update(req, api.WithUser(ctx, user))
}
handler.ServeHTTP(w, req)
}),
)
}
// authenticationHandlerFilter creates a filter object that will enforce authentication directly
func authenticationHandlerFilter(handler http.Handler, authenticator authenticator.Request, contextMapper kapi.RequestContextMapper) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
user, ok, err := authenticator.AuthenticateRequest(req)
if err != nil || !ok {
http.Error(w, "Unauthorized", http.StatusUnauthorized)
return
}
ctx, ok := contextMapper.Get(req)
if !ok {
http.Error(w, "Unable to find request context", http.StatusInternalServerError)
return
}
if err := contextMapper.Update(req, kapi.WithUser(ctx, user)); err != nil {
glog.V(4).Infof("Error setting authenticated context: %v", err)
http.Error(w, "Unable to set authenticated request context", http.StatusInternalServerError)
return
}
handler.ServeHTTP(w, req)
})
}
// WithImpersonation is a filter that will inspect and check requests that attempt to change the user.Info for their requests
func WithImpersonation(handler http.Handler, requestContextMapper api.RequestContextMapper, a authorizer.Authorizer) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
impersonationRequests, err := buildImpersonationRequests(req.Header)
if err != nil {
glog.V(4).Infof("%v", err)
internalError(w, req, err)
return
}
if len(impersonationRequests) == 0 {
handler.ServeHTTP(w, req)
return
}
ctx, exists := requestContextMapper.Get(req)
if !exists {
internalError(w, req, errors.New("no context found for request"))
return
}
requestor, exists := api.UserFrom(ctx)
if !exists {
internalError(w, req, errors.New("no user found for request"))
return
}
// if groups are not specified, then we need to look them up differently depending on the type of user
// if they are specified, then they are the authority
groupsSpecified := len(req.Header[authenticationapi.ImpersonateGroupHeader]) > 0
// make sure we're allowed to impersonate each thing we're requesting. While we're iterating through, start building username
// and group information
username := ""
groups := []string{}
userExtra := map[string][]string{}
for _, impersonationRequest := range impersonationRequests {
actingAsAttributes := &authorizer.AttributesRecord{
User: requestor,
Verb: "impersonate",
APIGroup: impersonationRequest.GetObjectKind().GroupVersionKind().Group,
Namespace: impersonationRequest.Namespace,
Name: impersonationRequest.Name,
ResourceRequest: true,
}
switch impersonationRequest.GetObjectKind().GroupVersionKind().GroupKind() {
case api.Kind("ServiceAccount"):
actingAsAttributes.Resource = "serviceaccounts"
username = serviceaccount.MakeUsername(impersonationRequest.Namespace, impersonationRequest.Name)
if !groupsSpecified {
// if groups aren't specified for a service account, we know the groups because its a fixed mapping. Add them
groups = serviceaccount.MakeGroupNames(impersonationRequest.Namespace, impersonationRequest.Name)
}
case api.Kind("User"):
actingAsAttributes.Resource = "users"
username = impersonationRequest.Name
case api.Kind("Group"):
actingAsAttributes.Resource = "groups"
groups = append(groups, impersonationRequest.Name)
case authenticationapi.Kind("UserExtra"):
extraKey := impersonationRequest.FieldPath
extraValue := impersonationRequest.Name
actingAsAttributes.Resource = "userextras"
actingAsAttributes.Subresource = extraKey
userExtra[extraKey] = append(userExtra[extraKey], extraValue)
default:
glog.V(4).Infof("unknown impersonation request type: %v", impersonationRequest)
forbidden(actingAsAttributes, w, req, fmt.Sprintf("unknown impersonation request type: %v", impersonationRequest))
return
}
allowed, reason, err := a.Authorize(actingAsAttributes)
if err != nil || !allowed {
glog.V(4).Infof("Forbidden: %#v, Reason: %s, Error: %v", req.RequestURI, reason, err)
forbidden(actingAsAttributes, w, req, reason)
return
}
}
newUser := &user.DefaultInfo{
Name: username,
Groups: groups,
Extra: userExtra,
}
requestContextMapper.Update(req, api.WithUser(ctx, newUser))
oldUser, _ := api.UserFrom(ctx)
httplog.LogOf(req, w).Addf("%v is acting as %v", oldUser, newUser)
// clear all the impersonation headers from the request
req.Header.Del(authenticationapi.ImpersonateUserHeader)
req.Header.Del(authenticationapi.ImpersonateGroupHeader)
for headerName := range req.Header {
if strings.HasPrefix(headerName, authenticationapi.ImpersonateUserExtraHeaderPrefix) {
req.Header.Del(headerName)
}
}
handler.ServeHTTP(w, req)
})
}