Remove the KVM tab: proxy, routes, config and state fields, UI

Not needed — the KVMs are reached over WireGuard.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This commit is contained in:
Mitchell-Johnson
2026-11-09 23:52:38 -08:00
co-authored by Claude Opus 5.5
parent 5edad2de6a
commit 4b238ea93e
11 changed files with 13 additions and 845 deletions
-420
View File
@@ -1,420 +0,0 @@
package api
// IP-KVMs: a device's own web page, shown inside Ham Lab.
//
// The whole difficulty is that Ham Lab is served over TLS and a KVM usually is not, so a
// browser refuses to put the device's page in an iframe — mixed content, blocked before
// anything loads. The fix is to serve the device from Ham Lab's own origin, which also
// means it inherits Ham Lab's login instead of needing a second one, and makes the iframe
// same-origin.
//
// Proxying an arbitrary web app under a path prefix is the hard part, and nothing here
// knows anything about any particular device. A device UI asks for its assets by absolute
// path — "/assets/app.js", "/api/whatever" — which a prefix cannot rewrite away. So the
// prefix is only the entry point: any request Ham Lab does not serve itself is routed to
// whichever KVM the asking page belongs to, worked out from the Referer, and from a cookie
// when there is no Referer (a WebSocket upgrade, say). Ham Lab's own routes always win, so
// a device can never shadow the console.
import (
"crypto/rand"
"encoding/hex"
"encoding/json"
"errors"
"io"
"log"
"net/http"
"net/http/httputil"
"net/url"
"strings"
"sync"
"time"
"hamlab/internal/config"
"hamlab/internal/store"
)
const kvmPrefix = "/kvm/"
const kvmCookie = "hamlab_kvm"
type kvmProxies struct {
mu sync.Mutex
m map[string]*httputil.ReverseProxy
}
func (s *Server) kvm(id string) (config.KVM, bool) {
var found config.KVM
ok := false
s.cfg.View(func(c *config.Config) {
for _, k := range c.KVMs {
if k.ID == id {
found, ok = k, true
}
}
})
return found, ok
}
// kvmProxy is the reverse proxy for one device, made once and kept.
func (s *Server) kvmProxy(k config.KVM) (*httputil.ReverseProxy, error) {
s.kvms.mu.Lock()
defer s.kvms.mu.Unlock()
if s.kvms.m == nil {
s.kvms.m = map[string]*httputil.ReverseProxy{}
}
if p, ok := s.kvms.m[k.ID]; ok {
return p, nil
}
target, err := url.Parse(k.URL)
if err != nil || target.Host == "" {
return nil, errors.New("this KVM's address is not a URL")
}
prefix := kvmPrefix + k.ID
p := &httputil.ReverseProxy{
Director: func(r *http.Request) {
r.URL.Scheme, r.URL.Host = target.Scheme, target.Host
// Entry through the prefix keeps the path after it; anything else arrived by its
// own absolute path and is passed through untouched.
if rest, ok := strings.CutPrefix(r.URL.Path, prefix); ok {
if rest == "" {
rest = "/"
}
r.URL.Path = rest
}
r.URL.RawPath = ""
r.Host = target.Host
// Whether the console itself is on TLS: the response rewriter needs to know, and by
// then only the outbound request is in hand.
if secure(r) {
r.Header.Set(kvmSecureHeader, "1")
} else {
r.Header.Del(kvmSecureHeader)
}
// The device gets its own host and none of Ham Lab's session.
r.Header.Del("Origin")
stripCookie(r, cookieName, kvmCookie)
// What is left is the device's own login. A browser that has it teaches the hub; one
// that has not is lent what the hub remembers, so the device sees a signed-in client.
if own := r.Cookies(); len(own) > 0 {
s.rememberKVMCookies(k.ID, own)
} else {
for name, val := range s.kvmCookies(k.ID) {
r.AddCookie(&http.Cookie{Name: name, Value: val})
}
}
},
FlushInterval: -1, // a video stream must not be buffered
ModifyResponse: func(resp *http.Response) error {
// The device's own framing and transport policy would stop it being embedded, or
// send a browser off to plain HTTP. Ham Lab is the origin now, and says what it
// serves; its own headers are added on the way out.
for _, h := range []string{"X-Frame-Options", "Content-Security-Policy", "Content-Security-Policy-Report-Only", "Strict-Transport-Security", "Referrer-Policy"} {
resp.Header.Del(h)
}
// A cookie the device sets by header is kept for Ham Lab's origin — so its Domain
// (the device's) goes, Secure follows the console rather than the device, and the
// hub remembers it too.
if set := resp.Cookies(); len(set) > 0 {
https := resp.Request != nil && resp.Request.Header.Get(kvmSecureHeader) == "1"
resp.Header.Del("Set-Cookie")
for _, c := range set {
c.Domain = ""
if c.Path == "" {
c.Path = "/"
}
c.Secure = c.Secure && https
if v := c.String(); v != "" {
resp.Header.Add("Set-Cookie", v)
}
}
s.rememberKVMCookies(k.ID, set)
}
// A redirect to the device's own root has to come back through the prefix.
if loc := resp.Header.Get("Location"); loc != "" {
if u, err := url.Parse(loc); err == nil && (u.Host == "" || u.Host == target.Host) && strings.HasPrefix(u.Path, "/") && !strings.HasPrefix(u.Path, prefix) {
u.Scheme, u.Host = "", ""
u.Path = prefix + u.Path
resp.Header.Set("Location", u.String())
}
}
return nil
},
ErrorHandler: func(w http.ResponseWriter, r *http.Request, err error) {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusBadGateway)
_ = json.NewEncoder(w).Encode(map[string]string{"error": k.Name + " unreachable: " + err.Error()})
},
}
s.kvms.m[k.ID] = p
return p, nil
}
// kvmSecureHeader rides on the outbound request to say whether the console was reached
// over TLS; the device ignores it.
const kvmSecureHeader = "X-Hamlab-Secure"
// kvmCookies is what the hub remembers of a device's own cookies — its login, in practice.
func (s *Server) kvmCookies(id string) map[string]string {
var out map[string]string
s.store.View(func(st *store.State) {
if m := st.KVMCookies[id]; len(m) > 0 {
out = make(map[string]string, len(m))
for k, v := range m {
out[k] = v
}
}
})
return out
}
// rememberKVMCookies keeps the cookies a browser (or the device's own Set-Cookie) carries
// for a KVM, so that a browser without them can be lent them. A cookie emptied or expired
// by the device is forgotten. Written only when something changed: this runs on every
// proxied request.
func (s *Server) rememberKVMCookies(id string, cs []*http.Cookie) {
have := s.kvmCookies(id)
changed := false
for _, c := range cs {
if c.Name == "" || c.Name == cookieName || c.Name == kvmCookie {
continue
}
gone := c.Value == "" || c.MaxAge < 0 || (!c.Expires.IsZero() && c.Expires.Before(time.Now()))
if gone {
if _, ok := have[c.Name]; ok {
changed = true
}
continue
}
if have[c.Name] != c.Value {
changed = true
}
}
if !changed {
return
}
_ = s.store.Update(func(st *store.State) {
if st.KVMCookies == nil {
st.KVMCookies = map[string]map[string]string{}
}
m := st.KVMCookies[id]
if m == nil {
m = map[string]string{}
}
for _, c := range cs {
if c.Name == "" || c.Name == cookieName || c.Name == kvmCookie {
continue
}
if c.Value == "" || c.MaxAge < 0 || (!c.Expires.IsZero() && c.Expires.Before(time.Now())) {
delete(m, c.Name)
} else {
m[c.Name] = c.Value
}
}
if len(m) == 0 {
delete(st.KVMCookies, id)
} else {
st.KVMCookies[id] = m
}
})
}
// forgetKVMCookies drops a device's remembered login — when the device is removed.
func (s *Server) forgetKVMCookies(id string) {
_ = s.store.Update(func(st *store.State) { delete(st.KVMCookies, id) })
}
// lendKVMCookies hands the browser the device cookies the hub remembers and it lacks, as
// the device's own page would have set them: readable by its scripts, for Ham Lab's whole
// origin, kept for half a year. The device's SPA checks for its token client-side before it
// ever asks the server, so lending it only on the wire would still land on the login form.
func (s *Server) lendKVMCookies(w http.ResponseWriter, r *http.Request, id string) {
for name, val := range s.kvmCookies(id) {
if _, err := r.Cookie(name); err == nil {
continue
}
http.SetCookie(w, &http.Cookie{Name: name, Value: val, Path: "/", MaxAge: 180 * 24 * 3600, Secure: secure(r), SameSite: http.SameSiteLaxMode})
}
}
// stripCookie removes named cookies from a request, so Ham Lab's session is never handed to
// a device and the device never sees which KVM the browser is looking at.
func stripCookie(r *http.Request, names ...string) {
cs := r.Cookies()
kept := cs[:0]
for _, c := range cs {
drop := false
for _, n := range names {
if c.Name == n {
drop = true
}
}
if !drop {
kept = append(kept, c)
}
}
r.Header.Del("Cookie")
for _, c := range kept {
r.AddCookie(c)
}
}
func (s *Server) forgetKVMProxy(id string) {
s.kvms.mu.Lock()
delete(s.kvms.m, id)
s.kvms.mu.Unlock()
}
// serveKVM is the entry point: /kvm/<id>/… . It also drops a cookie naming the device, so
// that requests the page makes later by absolute path can be traced back to it.
func (s *Server) serveKVM(w http.ResponseWriter, r *http.Request) {
id := r.PathValue("id")
k, ok := s.kvm(id)
if !ok {
jsonErr(w, 404, "no such KVM")
return
}
p, err := s.kvmProxy(k)
if err != nil {
jsonErr(w, 400, err.Error())
return
}
http.SetCookie(w, &http.Cookie{Name: kvmCookie, Value: id, Path: "/", HttpOnly: true, Secure: secure(r), SameSite: http.SameSiteLaxMode})
s.lendKVMCookies(w, r, id)
p.ServeHTTP(w, r)
}
// kvmFor works out which device a request belongs to when it arrived by absolute path
// rather than through the prefix: the Referer names the page that asked, and a cookie
// covers what has no Referer at all. Nothing device-specific: it never has to know which
// paths a given KVM uses.
func (s *Server) kvmFor(r *http.Request) (config.KVM, bool) {
if ref := r.Header.Get("Referer"); ref != "" {
if u, err := url.Parse(ref); err == nil {
if rest, ok := strings.CutPrefix(u.Path, kvmPrefix); ok {
if id, _, _ := strings.Cut(rest, "/"); id != "" {
if k, ok := s.kvm(id); ok {
return k, true
}
}
}
}
// asked for by a page that is not a KVM: not ours to answer
return config.KVM{}, false
}
if c, err := r.Cookie(kvmCookie); err == nil && c.Value != "" {
return s.kvm(c.Value)
}
return config.KVM{}, false
}
// kvmFallback answers a request Ham Lab does not serve itself, when it came from inside a
// KVM's page. It returns false when the request has nothing to do with a KVM, and the
// caller carries on with its own 404.
func (s *Server) kvmFallback(w http.ResponseWriter, r *http.Request) bool {
k, ok := s.kvmFor(r)
if !ok {
return false
}
p, err := s.kvmProxy(k)
if err != nil {
return false
}
p.ServeHTTP(w, r)
return true
}
func machineLabel(m string) string {
if m == "" {
return "this host"
}
return m
}
// ---- the list ----
func (s *Server) listKVMs(w http.ResponseWriter, _ *http.Request) {
out := []config.KVM{}
s.cfg.View(func(c *config.Config) { out = append(out, c.KVMs...) })
jsonOK(w, 200, out)
}
func (s *Server) addKVM(w http.ResponseWriter, r *http.Request) {
var body struct{ Name, URL, Machine string }
if err := json.NewDecoder(io.LimitReader(r.Body, 4096)).Decode(&body); err != nil {
jsonErr(w, 400, "bad request")
return
}
raw := strings.TrimSpace(body.URL)
if raw != "" && !strings.Contains(raw, "://") {
raw = "http://" + raw // what you would type: an address, not a scheme
}
u, err := url.Parse(raw)
if err != nil || (u.Scheme != "http" && u.Scheme != "https") || u.Host == "" {
jsonErr(w, 400, "address: http(s)://host, or just the host")
return
}
name := strings.TrimSpace(body.Name)
if name == "" {
name = u.Host
}
if len(name) > maxNameLen {
jsonErr(w, 400, "that name is too long")
return
}
b := make([]byte, 6)
if _, err := rand.Read(b); err != nil {
jsonErr(w, 500, err.Error())
return
}
machine := strings.TrimSpace(body.Machine)
k := config.KVM{ID: hex.EncodeToString(b), Name: name, URL: u.Scheme + "://" + u.Host + strings.TrimSuffix(u.Path, "/"), Machine: machine, Added: time.Now()}
// One per machine: a second one for the same host replaces the first rather than sitting
// beside it, since the tab shows the machine you are looking at.
var replaced string
if err := s.cfg.Update(func(c *config.Config) {
kept := c.KVMs[:0]
for _, old := range c.KVMs {
if old.Machine == machine {
replaced = old.ID
continue
}
kept = append(kept, old)
}
c.KVMs = append(kept, k)
}); err != nil {
jsonErr(w, 500, err.Error())
return
}
if replaced != "" {
s.forgetKVMProxy(replaced)
}
log.Printf("kvm %q added for %s (%s) by %s", k.Name, machineLabel(machine), k.URL, clientIP(r))
jsonOK(w, 201, k)
}
func (s *Server) removeKVM(w http.ResponseWriter, r *http.Request) {
id := r.PathValue("id")
found := false
if err := s.cfg.Update(func(c *config.Config) {
kept := c.KVMs[:0]
for _, k := range c.KVMs {
if k.ID == id {
found = true
continue
}
kept = append(kept, k)
}
c.KVMs = kept
}); err != nil {
jsonErr(w, 500, err.Error())
return
}
if !found {
jsonErr(w, 404, "no such KVM")
return
}
s.forgetKVMProxy(id)
s.forgetKVMCookies(id)
log.Printf("kvm %s removed by %s", id, clientIP(r))
w.WriteHeader(204)
}
-123
View File
@@ -1,123 +0,0 @@
package api
import (
"net/http"
"net/http/httptest"
"net/url"
"path/filepath"
"strings"
"testing"
"hamlab/internal/auth"
"hamlab/internal/config"
"hamlab/internal/store"
)
// A KVM's own login is a cookie its page sets in one browser. The hub remembers it from the
// requests that carry it, lends it to a browser that lacks it — both on the wire to the
// device and back to the browser, since the device's page checks for it client-side — and
// forgets it when the device says it is gone or the KVM is removed.
func TestKVMCookiesAreRememberedAndLent(t *testing.T) {
var seen []string // the Cookie header the fake device received, per request
device := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
seen = append(seen, r.Header.Get("Cookie"))
if r.URL.Path == "/api/auth/login" {
// a device that sets its token by header, with its own domain and Secure
http.SetCookie(w, &http.Cookie{Name: "nano-kvm-token", Value: "tok-1", Domain: "10.0.0.217", Secure: true})
}
if r.URL.Path == "/api/auth/logout" {
http.SetCookie(w, &http.Cookie{Name: "nano-kvm-token", Value: "", MaxAge: -1})
}
w.WriteHeader(200)
}))
defer device.Close()
dir := t.TempDir()
cfg := config.Default(filepath.Join(dir, "config.json"))
if err := cfg.Update(func(c *config.Config) {
c.KVMs = []config.KVM{{ID: "abc123", Name: "test", URL: device.URL, Machine: ""}}
}); err != nil {
t.Fatal(err)
}
st, err := store.Open(filepath.Join(dir, "state.json"))
if err != nil {
t.Fatal(err)
}
s := &Server{cfg: cfg, store: st, sessions: auth.NewSessions(st)}
k, _ := s.kvm("abc123")
p, err := s.kvmProxy(k)
if err != nil {
t.Fatal(err)
}
ask := func(path string, cookies ...*http.Cookie) *httptest.ResponseRecorder {
r := httptest.NewRequest("GET", path, nil)
r.SetPathValue("id", "abc123")
for _, c := range cookies {
r.AddCookie(c)
}
w := httptest.NewRecorder()
if strings.HasPrefix(path, kvmPrefix) {
s.serveKVM(w, r)
} else {
p.ServeHTTP(w, r)
}
return w
}
// 1. the device sets its token by header: it reaches the browser without the device's
// domain or Secure (plain-http console), and the hub remembers it
w := ask("/api/auth/login", &http.Cookie{Name: cookieName, Value: "hamlab-session"})
var set *http.Cookie
for _, c := range w.Result().Cookies() {
if c.Name == "nano-kvm-token" {
set = c
}
}
if set == nil || set.Domain != "" || set.Secure || set.Value != "tok-1" || set.Path != "/" {
t.Fatalf("rewritten Set-Cookie = %+v, want nano-kvm-token=tok-1 for / without Domain or Secure", set)
}
if got := s.kvmCookies("abc123"); got["nano-kvm-token"] != "tok-1" {
t.Fatalf("remembered = %v, want the token", got)
}
if strings.Contains(seen[0], "hamlab_session") {
t.Fatalf("the device was handed Ham Lab's session: %q", seen[0])
}
// 2. a browser that has the cookie teaches a newer value
ask("/api/vm/info", &http.Cookie{Name: "nano-kvm-token", Value: "tok-2"}, &http.Cookie{Name: cookieName, Value: "x"})
if got := s.kvmCookies("abc123"); got["nano-kvm-token"] != "tok-2" {
t.Fatalf("remembered = %v, want tok-2", got)
}
if seen[1] != "nano-kvm-token=tok-2" {
t.Fatalf("device saw %q, want the browser's own cookie only", seen[1])
}
// 3. a browser without it is lent it: on the wire, and back as a Set-Cookie it can read
w = ask(kvmPrefix+"abc123/", &http.Cookie{Name: cookieName, Value: "x"})
if seen[2] != "nano-kvm-token=tok-2" {
t.Fatalf("device saw %q from a browser with no cookie, want the remembered token", seen[2])
}
lent := false
for _, c := range w.Result().Cookies() {
if c.Name == "nano-kvm-token" && c.Value == "tok-2" && !c.HttpOnly && c.Path == "/" && c.MaxAge > 0 {
lent = true
}
}
if !lent {
t.Fatalf("browser was not lent the token: %v", w.Result().Cookies())
}
// 4. the device logging out forgets it
ask("/api/auth/logout", &http.Cookie{Name: "nano-kvm-token", Value: "tok-2"})
if got := s.kvmCookies("abc123"); got != nil {
t.Fatalf("after logout remembered = %v, want nothing", got)
}
// 5. removing the KVM clears whatever is left
s.rememberKVMCookies("abc123", []*http.Cookie{{Name: "nano-kvm-token", Value: "tok-3"}})
s.forgetKVMCookies("abc123")
if got := s.kvmCookies("abc123"); got != nil {
t.Fatalf("after remove remembered = %v, want nothing", got)
}
_ = url.Parse
}
+4 -28
View File
@@ -75,7 +75,6 @@ type Server struct {
net *network.Watcher
update updateState
events eventLog
kvms kvmProxies
fsLocal files.FS
fsSudo files.FS // nil without passwordless sudo
thumbs *thumbSvc
@@ -351,18 +350,7 @@ func (s *Server) routes() *http.ServeMux {
m.HandleFunc("PUT /api/prefs/sampler", s.auth(s.putSampler))
m.HandleFunc("GET /api/prefs/history", s.auth(s.getHistoryWindow))
m.HandleFunc("PUT /api/prefs/history", s.auth(s.putHistoryWindow))
m.HandleFunc("GET /api/kvms", s.auth(s.listKVMs))
m.HandleFunc("POST /api/kvms", s.auth(s.addKVM))
m.HandleFunc("DELETE /api/kvms/{id}", s.auth(s.removeKVM))
m.HandleFunc("/kvm/{id}/{rest...}", s.auth(s.serveKVM))
m.HandleFunc("/kvm/{id}", s.auth(s.serveKVM))
// A path Ham Lab does not serve may still belong to a KVM's page, which asks for its
// own assets by absolute path. Ham Lab's own routes matched first, so this can only
// catch what would otherwise have been a 404.
m.HandleFunc("/api/", s.auth(func(w http.ResponseWriter, r *http.Request) {
if s.kvmFallback(w, r) {
return
}
jsonErr(w, 404, "not found")
}))
m.HandleFunc("/", s.static)
@@ -386,16 +374,10 @@ func sensorPath(p string) bool {
func (s *Server) Handler() http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
h := w.Header()
// The console must never be framed. Two exceptions: an embedded widget exists to be
// (a page that can only read sensors, and only with a read-only token in its URL),
// and a proxied KVM is framed by the console itself — 'none' forbids that even from
// the same origin, so those paths say 'self' instead of opening up.
switch {
case r.URL.Path == "/embed/widget":
case strings.HasPrefix(r.URL.Path, kvmPrefix):
h.Set("X-Frame-Options", "SAMEORIGIN")
h.Set("Content-Security-Policy", "frame-ancestors 'self'")
default:
// The console must never be framed. The one exception is an embedded widget, which
// exists to be (a page that can only read sensors, and only with a read-only token in
// its URL).
if r.URL.Path != "/embed/widget" {
h.Set("X-Frame-Options", "DENY")
h.Set("Content-Security-Policy", "frame-ancestors 'none'")
}
@@ -2654,12 +2636,6 @@ func (s *Server) static(w http.ResponseWriter, r *http.Request) {
return
}
}
// A path with no file of ours behind it may belong to a KVM's page, which asks for its
// own assets by absolute path. Checked here rather than in the router because this
// handler is the catch-all — and gated on a session, since this handler is public.
if s.signedIn(r) && s.kvmFallback(w, r) {
return
}
// SPA fallback
w.Header().Set("Cache-Control", "no-cache")
http.ServeFileFS(w, r, s.ui, "index.html")
-18
View File
@@ -77,23 +77,6 @@ type UpdateSource struct {
Check string `json:"check,omitempty"`
}
// KVM is an IP-KVM: a device with a web page that gives screen, keyboard and mouse access
// to a machine, including when that machine has no OS running. Ham Lab holds the list on
// the hub and proxies each one, because a KVM matters exactly when the machine it is
// attached to cannot answer for itself.
type KVM struct {
ID string `json:"id"`
Name string `json:"name"`
// URL is the device's own address, as you would type it into a browser on the LAN.
URL string `json:"url"`
// Machine is the host this KVM is attached to, and is the key: one KVM per machine, shown
// on that machine's KVM tab. Empty means the hub itself. The list lives on the hub even
// for a node's KVM, because a KVM earns its keep when the machine is down and cannot
// answer for itself.
Machine string `json:"machine"`
Added time.Time `json:"added"`
}
type Config struct {
Listen string `json:"listen"`
// PasswordHash is the single login of installs before users existed. On load it becomes
@@ -103,7 +86,6 @@ type Config struct {
TLS string `json:"tls,omitempty"` // "auto" → self-signed cert in the data dir; "" → plain HTTP
Tokens []Token `json:"tokens,omitempty"`
Nodes []Node `json:"nodes,omitempty"`
KVMs []KVM `json:"kvms,omitempty"`
// Updates: where a newer build comes from. See UpdateSource.
Updates UpdateSource `json:"update,omitempty"`
+3 -7
View File
@@ -68,13 +68,9 @@ type State struct {
// Mounts remembers where a container's bind mounts pointed, so a stack deployed by an
// orchestrator that has since been removed can still be found on disk. See
// internal/api/stacks.go.
Mounts []RememberedMount `json:"mounts,omitempty"`
// KVMCookies is each KVM's own login, as the cookies its page set in a browser: kept so
// the next browser — or this one after it has forgotten them — is signed into the device
// already. See internal/api/kvm.go.
KVMCookies map[string]map[string]string `json:"kvm_cookies,omitempty"`
SamplerMs int `json:"sampler_ms,omitempty"` // how often this machine samples; the hub keeps every machine on the console's refresh rate
HistorySec int `json:"history_sec,omitempty"` // how far back the graphs reach; the hub keeps every machine on the same one
Mounts []RememberedMount `json:"mounts,omitempty"`
SamplerMs int `json:"sampler_ms,omitempty"` // how often this machine samples; the hub keeps every machine on the console's refresh rate
HistorySec int `json:"history_sec,omitempty"` // how far back the graphs reach; the hub keeps every machine on the same one
// Transcode is where videos played in the Files viewer are made (internal/api/play.go):
// a machine and a device on it. nil is the machine the file is on, its best device.
Transcode *Transcode `json:"transcode,omitempty"`