Check Update

README.md

@@ -286,6 +286,15 @@ https://git.dr2.site/penguinehis/DragonCoreSSH-NewWEB.git
 
 Depois ele recompila o binário e atualiza o painel web e os scripts auxiliares, mantendo as configurações e dados existentes.
 
+O painel do superadmin também mostra um cartão **Atualizações do painel** na tela inicial. Ele compara o commit compilado no servidor com o commit mais recente da branch configurada no Git. A verificação usa cache de 5 minutos; o botão **Verificar agora** força uma nova consulta.
+
+Variáveis opcionais do serviço para apontar a verificação para outro Git/branch:
+
+```text
+DRAGON_UPDATE_REPO_URL=https://git.dr2.site/penguinehis/DragonCoreSSH-NewWEB.git
+DRAGON_UPDATE_BRANCH=main
+```
+
 O update preserva:
 
 ```text
@@ -788,6 +797,15 @@ https://git.dr2.site/penguinehis/DragonCoreSSH-NewWEB.git
 
 Then it rebuilds the binary and updates the web panel and helper scripts while keeping existing configuration and user data.
 
+The superadmin dashboard also shows a **Panel Updates** card. It compares the commit compiled into the running server with the latest commit on the configured Git branch. Results are cached for 5 minutes; **Check now** forces a fresh lookup.
+
+Optional service variables for a different repository/branch:
+
+```text
+DRAGON_UPDATE_REPO_URL=https://git.dr2.site/penguinehis/DragonCoreSSH-NewWEB.git
+DRAGON_UPDATE_BRANCH=main
+```
+
 The update preserves:
 
 ```text

admin/assets/app.css

@@ -638,3 +638,14 @@ select:disabled {
   color:#f3f7ff;
   font-size:.78rem;
 }
+
+/* Git update status card */
+.update-commit{
+  font-family:ui-monospace,SFMono-Regular,Consolas,"Liberation Mono",monospace;
+  font-size:1rem!important;
+  letter-spacing:.01em!important;
+  overflow-wrap:anywhere;
+}
+.update-check-time{font-size:.9rem!important;letter-spacing:0!important;}
+.update-statusbar{align-items:center;gap:12px;flex-wrap:wrap;}
+.btn-xs{padding:5px 8px!important;font-size:.67rem!important;border-radius:9px!important;}

admin/assets/js/01-core.js

@@ -96,6 +96,22 @@ Object.assign(I18N_ALIASES, {
   "Public Key — share with dnstt clients":"Public Key — share with dnstt clients","Chave pública — compartilhe com clientes DNSTT":"Public Key — share with dnstt clients",
   "Máx. sessões UDP por cliente":"Max UDP Sessions Per Client","(não é o total de usuários do servidor)":"(not total server users)","Nome do serviço":"Service Name","Modo":"Mode","Protocolo":"Protocol","Porta":"Port","IP de listen":"Listen IP","Método":"Method","Caminho":"Path","Destino":"Dest","ID curto":"Short ID","Nome do servidor":"Server Name","Caminho do arquivo cert":"Cert File Path","Caminho do arquivo key":"Key File Path","Fonte do certificado:":"Certificate source:","Autoassinado":"Self-Signed","Colar PEM":"Paste PEM","Caminho do arquivo":"File Path","Salvar PEM":"Save PEM","Intervalo de reinício automático":"Auto Restart Interval","Atraso para reiniciar":"Restart Grace Delay","0s/off desativa":"0s/off disables","Chave pública":"Public Key","Nome do domínio":"Domain Name"
 });
+Object.assign(I18N_TEXT["en-US"], {
+  "Panel Updates":"Panel Updates","Checking…":"Checking…","Open Git":"Open Git","Check now":"Check now","Installed version":"Installed version","Latest Git version":"Latest Git version","Branch":"Branch","Last checked":"Last checked",
+  "Comparing the installed version with the Git repository.":"Comparing the installed version with the Git repository.","To update:":"To update:","Copy command":"Copy command","Up to date":"Up to date","Update available":"Update available","Local changes":"Local changes","Unknown":"Unknown",
+  "The installed version matches the latest commit on {branch}.":"The installed version matches the latest commit on {branch}.","A newer commit is available on {branch}.":"A newer commit is available on {branch}.","This build contains local changes, so it cannot be compared safely.":"This build contains local changes, so it cannot be compared safely.",
+  "Could not check for updates: {error}":"Could not check for updates: {error}","The update status could not be determined.":"The update status could not be determined.","Checking repository…":"Checking repository…","Update check timed out.":"Update check timed out.","Could not reach the Git repository.":"Could not reach the Git repository.","Current build commit is unavailable.":"Current build commit is unavailable.","Unknown update-check error.":"Unknown update-check error.","Copied":"Copied"
+});
+Object.assign(I18N_TEXT["pt-BR"], {
+  "Panel Updates":"Atualizações do painel","Checking…":"Verificando…","Open Git":"Abrir Git","Check now":"Verificar agora","Installed version":"Versão instalada","Latest Git version":"Última versão no Git","Branch":"Branch","Last checked":"Última verificação",
+  "Comparing the installed version with the Git repository.":"Comparando a versão instalada com o repositório Git.","To update:":"Para atualizar:","Copy command":"Copiar comando","Up to date":"Atualizado","Update available":"Atualização disponível","Local changes":"Alterações locais","Unknown":"Desconhecido",
+  "The installed version matches the latest commit on {branch}.":"A versão instalada corresponde ao commit mais recente da branch {branch}.","A newer commit is available on {branch}.":"Existe um commit mais recente disponível na branch {branch}.","This build contains local changes, so it cannot be compared safely.":"Esta compilação contém alterações locais e não pode ser comparada com segurança.",
+  "Could not check for updates: {error}":"Não foi possível verificar atualizações: {error}","The update status could not be determined.":"Não foi possível determinar o status da atualização.","Checking repository…":"Verificando o repositório…","Update check timed out.":"A verificação de atualização excedeu o tempo limite.","Could not reach the Git repository.":"Não foi possível acessar o repositório Git.","Current build commit is unavailable.":"O commit da compilação atual não está disponível.","Unknown update-check error.":"Erro desconhecido ao verificar atualização.","Copied":"Copiado"
+});
+Object.assign(I18N_ALIASES, {
+  "Atualizações do painel":"Panel Updates","Verificando…":"Checking…","Abrir Git":"Open Git","Verificar agora":"Check now","Versão instalada":"Installed version","Última versão no Git":"Latest Git version","Última verificação":"Last checked",
+  "Comparando a versão instalada com o repositório Git.":"Comparing the installed version with the Git repository.","Para atualizar:":"To update:","Copiar comando":"Copy command","Atualizado":"Up to date","Atualização disponível":"Update available","Alterações locais":"Local changes","Desconhecido":"Unknown"
+});
 const I18N_REVERSE = Object.fromEntries(SUPPORTED_LANGS.map(lang => [lang, Object.fromEntries(Object.entries(I18N_TEXT[lang] || {}).map(([k, v]) => [v, k]))]));
 let currentLang = detectInitialLanguage();
 let i18nTranslating = false;

admin/assets/js/02-shell.js

@@ -124,6 +124,7 @@ function initAfterLogin() {
 
   if (currentRole === "superadmin") {
     loadDashboardStats();
+    if (typeof loadUpdateStatus === "function") loadUpdateStatus();
     statsTimer = setInterval(() => {
       loadDashboardStats();
       if (currentTab === "stats") loadStats();

admin/assets/js/11-update-status.js

@@ -0,0 +1,119 @@
+// ─── Git update status ───────────────────────────────────────────────────────
+const DRAGON_UPDATE_COMMAND = "sudo bash /opt/sshpanel/update.sh";
+
+function updateStatusErrorText(error) {
+  switch (String(error || "")) {
+    case "remote update check timed out":
+      return t("Update check timed out.");
+    case "could not read the remote Git branch":
+      return t("Could not reach the Git repository.");
+    case "current build commit is unavailable":
+      return t("Current build commit is unavailable.");
+    default:
+      return error || t("Unknown update-check error.");
+  }
+}
+
+function setUpdateState(label, tone = "") {
+  const chip = document.getElementById("updateStateChip");
+  if (!chip) return;
+  chip.className = "chip" + (tone ? ` ${tone}` : "");
+  chip.textContent = label;
+}
+
+function setCommitValue(elementID, shortValue, fullValue) {
+  const el = document.getElementById(elementID);
+  if (!el) return;
+  el.textContent = shortValue || "--";
+  el.title = fullValue || "";
+}
+
+function renderUpdateStatus(data) {
+  setCommitValue("updateCurrentCommit", data.current_commit_short, data.current_commit);
+  setCommitValue("updateLatestCommit", data.latest_commit_short, data.latest_commit);
+
+  const branch = document.getElementById("updateBranch");
+  if (branch) branch.textContent = data.branch || "main";
+
+  const checked = document.getElementById("updateCheckedAt");
+  if (checked) {
+    const date = data.checked_at ? new Date(data.checked_at) : null;
+    checked.textContent = date && Number.isFinite(date.getTime()) ? date.toLocaleString() : "--";
+  }
+
+  const repoLink = document.getElementById("updateRepoLink");
+  if (repoLink && data.repo_web_url) repoLink.href = data.repo_web_url;
+
+  const text = document.getElementById("updateStatusText");
+  const commandWrap = document.getElementById("updateCommandWrap");
+  commandWrap?.classList.toggle("hidden", !data.update_available);
+
+  if (data.status === "up_to_date") {
+    setUpdateState(t("Up to date"), "green");
+    if (text) text.textContent = t("The installed version matches the latest commit on {branch}.", { branch: data.branch || "main" });
+    return;
+  }
+
+  if (data.status === "update_available") {
+    setUpdateState(t("Update available"), "warn");
+    if (text) text.textContent = t("A newer commit is available on {branch}.", { branch: data.branch || "main" });
+    return;
+  }
+
+  if (data.status === "local_changes") {
+    setUpdateState(t("Local changes"), "warn");
+    if (text) text.textContent = t("This build contains local changes, so it cannot be compared safely.");
+    return;
+  }
+
+  setUpdateState(t("Unknown"), "red");
+  if (text) {
+    text.textContent = data.error
+      ? t("Could not check for updates: {error}", { error: updateStatusErrorText(data.error) })
+      : t("The update status could not be determined.");
+  }
+}
+
+async function loadUpdateStatus(force = false) {
+  if (currentRole !== "superadmin") return;
+
+  const button = document.getElementById("checkUpdateBtn");
+  const text = document.getElementById("updateStatusText");
+  if (button) button.disabled = true;
+  setUpdateState(t("Checking…"));
+  if (text) text.textContent = t("Checking repository…");
+
+  try {
+    const path = "/api/system/update-status" + (force ? "?refresh=1" : "");
+    const res = await api(path);
+    if (!res.ok) throw new Error(`HTTP ${res.status}`);
+    renderUpdateStatus(await res.json());
+  } catch (error) {
+    setUpdateState(t("Unknown"), "red");
+    if (text) text.textContent = t("Could not check for updates: {error}", { error: error.message || t("Network error.") });
+  } finally {
+    if (button) button.disabled = false;
+  }
+}
+
+document.getElementById("checkUpdateBtn")?.addEventListener("click", () => loadUpdateStatus(true));
+document.getElementById("copyUpdateCommandBtn")?.addEventListener("click", async () => {
+  try {
+    await navigator.clipboard.writeText(DRAGON_UPDATE_COMMAND);
+  } catch {
+    const input = document.createElement("textarea");
+    input.value = DRAGON_UPDATE_COMMAND;
+    input.style.position = "fixed";
+    input.style.opacity = "0";
+    document.body.appendChild(input);
+    input.select();
+    document.execCommand("copy");
+    input.remove();
+  }
+  const button = document.getElementById("copyUpdateCommandBtn");
+  if (button) {
+    const oldText = button.textContent;
+    button.textContent = t("Copied");
+    setTimeout(() => { button.textContent = oldText; }, 1400);
+  }
+});

admin/index.html

@@ -16,7 +16,7 @@
   setTimeout(function(){document.documentElement.classList.remove("i18n-pending");},2500);
 })();
 </script>
-<link rel="stylesheet" href="assets/app.css?v=20260511visualsafesave1"/>
+<link rel="stylesheet" href="assets/app.css?v=20260711updatecheck1"/>
 </head>
 <body>
 <div class="app">
@@ -158,6 +158,26 @@
       </div>
     </div>
 
+    <div class="card superadmin-only hidden" id="updateStatusCard" style="margin-top:18px;">
+      <div class="card-hdr">
+        <div class="card-title">Panel Updates <span class="chip" id="updateStateChip">Checking…</span></div>
+        <div class="card-actions">
+          <a class="btn btn-ghost btn-sm" id="updateRepoLink" href="https://git.dr2.site/penguinehis/DragonCoreSSH-NewWEB" target="_blank" rel="noopener noreferrer">Open Git</a>
+          <button class="btn btn-ghost btn-sm" type="button" id="checkUpdateBtn">Check now</button>
+        </div>
+      </div>
+      <div class="metrics">
+        <div class="metric"><div class="m-label">Installed version</div><div class="m-val update-commit" id="updateCurrentCommit">--</div></div>
+        <div class="metric"><div class="m-label">Latest Git version</div><div class="m-val update-commit" id="updateLatestCommit">--</div></div>
+        <div class="metric"><div class="m-label">Branch</div><div class="m-val update-commit" id="updateBranch">main</div></div>
+        <div class="metric"><div class="m-label">Last checked</div><div class="m-val update-check-time" id="updateCheckedAt">--</div></div>
+      </div>
+      <div class="statusbar update-statusbar">
+        <span id="updateStatusText">Comparing the installed version with the Git repository.</span>
+        <span class="hint hidden" id="updateCommandWrap">To update: <code>sudo bash /opt/sshpanel/update.sh</code> <button class="btn btn-ghost btn-xs" type="button" id="copyUpdateCommandBtn">Copy command</button></span>
+      </div>
+    </div>
+
     <div class="grid2 dashboard-lower">
       <div class="card hidden" id="dnsttDashboardCard">
         <div class="card-hdr">
@@ -1241,15 +1261,16 @@
 <!-- app.js was split into ordered modules for maintainability. They are plain
      classic scripts sharing one global scope; `defer` preserves execution order,
      so behavior is identical to the old single file. Keep this load order. -->
-<script defer src="assets/js/01-core.js?v=20260704ytquicfix1"></script>
+<script defer src="assets/js/01-core.js?v=20260711updatecheck1"></script>
-<script defer src="assets/js/02-shell.js?v=20260704ytquicfix1"></script>
+<script defer src="assets/js/02-shell.js?v=20260711updatecheck1"></script>
-<script defer src="assets/js/03-ssh-users.js?v=20260704ytquicfix1"></script>
+<script defer src="assets/js/03-ssh-users.js?v=20260711updatecheck1"></script>
-<script defer src="assets/js/04-xray.js?v=20260704ytquicfix1"></script>
+<script defer src="assets/js/04-xray.js?v=20260711updatecheck1"></script>
-<script defer src="assets/js/05-resellers.js?v=20260704ytquicfix1"></script>
+<script defer src="assets/js/05-resellers.js?v=20260711updatecheck1"></script>
-<script defer src="assets/js/06-servers.js?v=20260704ytquicfix1"></script>
+<script defer src="assets/js/06-servers.js?v=20260711updatecheck1"></script>
-<script defer src="assets/js/07-stats-logs.js?v=20260704ytquicfix1"></script>
+<script defer src="assets/js/07-stats-logs.js?v=20260711updatecheck1"></script>
-<script defer src="assets/js/08-server-config.js?v=20260704ytquicfix1"></script>
+<script defer src="assets/js/08-server-config.js?v=20260711updatecheck1"></script>
-<script defer src="assets/js/09-xray-wizard.js?v=20260704ytquicfix1"></script>
+<script defer src="assets/js/09-xray-wizard.js?v=20260711updatecheck1"></script>
-<script defer src="assets/js/10-boot.js?v=20260704ytquicfix1"></script>
+<script defer src="assets/js/11-update-status.js?v=20260711updatecheck1"></script>
+<script defer src="assets/js/10-boot.js?v=20260711updatecheck1"></script>
 </body>
 </html>

install.sh

@@ -15,6 +15,7 @@ LOG_TMPFS_SIZE="${LOG_TMPFS_SIZE:-15m}"
 PANEL_LOG_MAX_BYTES="${PANEL_LOG_MAX_BYTES:-1048576}"
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 GO_VERSION="${GO_VERSION:-$(awk '$1 == "go" {print $2; exit}' "$SCRIPT_DIR/go.mod" 2>/dev/null || echo "1.22.5")}"
+REPO_URL="${REPO_URL:-https://git.dr2.site/penguinehis/DragonCoreSSH-NewWEB.git}"
 MKDIR_BIN="$(command -v mkdir 2>/dev/null || true)"
 [[ -n "$MKDIR_BIN" ]] || MKDIR_BIN="/bin/mkdir"
 # ────────────────────────────────────────────────────────────────────────────
@@ -264,10 +265,25 @@ info "[5/10] Building SSH Panel binary…"
 cd "$SCRIPT_DIR"
 export GOPATH=/tmp/gopath_sshpanel
 export GOCACHE=/tmp/gocache_sshpanel
+BUILD_COMMIT="$(git -C "$SCRIPT_DIR" rev-parse HEAD 2>/dev/null || true)"
+BUILD_BRANCH="$(git -C "$SCRIPT_DIR" rev-parse --abbrev-ref HEAD 2>/dev/null || true)"
+BUILD_TIME="$(date -u +%Y-%m-%dT%H:%M:%SZ)"
+BUILD_REPO_URL="$(git -C "$SCRIPT_DIR" config --get remote.origin.url 2>/dev/null || true)"
+[[ -n "$BUILD_COMMIT" ]] || BUILD_COMMIT="unknown"
+[[ -n "$BUILD_BRANCH" && "$BUILD_BRANCH" != "HEAD" ]] || BUILD_BRANCH="main"
+[[ -n "$BUILD_REPO_URL" ]] || BUILD_REPO_URL="$REPO_URL"
+
 go mod download
 go mod tidy
-go build -ldflags="-s -w" -o "$INSTALL_DIR/sshpanel" .
+go build -ldflags="-s -w -X main.buildCommit=$BUILD_COMMIT -X main.buildBranch=$BUILD_BRANCH -X main.buildTime=$BUILD_TIME" -o "$INSTALL_DIR/sshpanel" .
+printf '%s\n' "$BUILD_COMMIT" > "$INSTALL_DIR/.installed_commit"
+printf '%s\n' "$BUILD_BRANCH" > "$INSTALL_DIR/.installed_branch"
+printf '%s\n' "$BUILD_TIME" > "$INSTALL_DIR/.installed_build_time"
+printf '%s\n' "$BUILD_REPO_URL" > "$INSTALL_DIR/.installed_repo_url"
+chmod 0644 "$INSTALL_DIR/.installed_commit" "$INSTALL_DIR/.installed_branch" "$INSTALL_DIR/.installed_build_time"
+chmod 0600 "$INSTALL_DIR/.installed_repo_url"
 info "  Binary: $INSTALL_DIR/sshpanel"
+info "  Build commit: $BUILD_COMMIT ($BUILD_BRANCH)"
 cp -r "$SCRIPT_DIR/admin/"* "$INSTALL_DIR/admin/"
 info "  Admin panel copied"
 if [[ -f "$SCRIPT_DIR/update.sh" ]]; then

main.go

@@ -1567,6 +1567,7 @@ func startAdminAPI(store *Store, addr string, adminDir string) {
 	mux.Handle("/api/vnstat/reset", saSession(http.HandlerFunc(handleVnstatReset(store))))
 	mux.Handle("/api/system/logs", saSession(http.HandlerFunc(handleSystemLogs)))
 	mux.Handle("/api/system/logs/reset", saSession(http.HandlerFunc(handleSystemLogsReset)))
+	mux.Handle("/api/system/update-status", saSession(http.HandlerFunc(handleUpdateStatus)))
 	mux.Handle("/api/dnstt", saSession(http.HandlerFunc(handleDnsttStats)))
 	mux.Handle("/api/dnstt/logs", saSession(http.HandlerFunc(handleDnsttLogs)))
 

update.sh

@@ -36,6 +36,10 @@ MKDIR_BIN="$(command -v mkdir 2>/dev/null || true)"
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 SOURCE_DIR=""
 RESTART_NEEDED=false
+BUILD_COMMIT=""
+BUILD_BRANCH=""
+BUILD_TIME=""
+BUILD_REPO_URL=""
 
 [[ $EUID -ne 0 ]] && error "Run as root: sudo bash $0"
 
@@ -288,9 +292,18 @@ build_binary() {
   cd "$SOURCE_DIR"
   export GOPATH=/tmp/gopath_sshpanel
   export GOCACHE=/tmp/gocache_sshpanel
+
+  BUILD_COMMIT="$(git -C "$SOURCE_DIR" rev-parse HEAD 2>/dev/null || true)"
+  BUILD_BRANCH="${UPDATE_REF:-$(git -C "$SOURCE_DIR" rev-parse --abbrev-ref HEAD 2>/dev/null || true)}"
+  BUILD_TIME="$(date -u +%Y-%m-%dT%H:%M:%SZ)"
+  BUILD_REPO_URL="$REPO_URL"
+  [[ -n "$BUILD_COMMIT" ]] || BUILD_COMMIT="unknown"
+  [[ -n "$BUILD_BRANCH" && "$BUILD_BRANCH" != "HEAD" ]] || BUILD_BRANCH="main"
+
   go mod download
   go mod tidy
-  go build -ldflags="-s -w" -o /tmp/sshpanel_new .
+  go build -ldflags="-s -w -X main.buildCommit=$BUILD_COMMIT -X main.buildBranch=$BUILD_BRANCH -X main.buildTime=$BUILD_TIME" -o /tmp/sshpanel_new .
+  info "  Build commit: $BUILD_COMMIT ($BUILD_BRANCH)"
   info "  Build complete."
 }
 
@@ -332,6 +345,14 @@ apply_update() {
   chmod 755 "$INSTALL_DIR/sshpanel"
   info "  Binary updated."
 
+  printf '%s\n' "$BUILD_COMMIT" > "$INSTALL_DIR/.installed_commit"
+  printf '%s\n' "$BUILD_BRANCH" > "$INSTALL_DIR/.installed_branch"
+  printf '%s\n' "$BUILD_TIME" > "$INSTALL_DIR/.installed_build_time"
+  printf '%s\n' "$BUILD_REPO_URL" > "$INSTALL_DIR/.installed_repo_url"
+  chmod 0644 "$INSTALL_DIR/.installed_commit" "$INSTALL_DIR/.installed_branch" "$INSTALL_DIR/.installed_build_time"
+  chmod 0600 "$INSTALL_DIR/.installed_repo_url"
+  info "  Build metadata updated."
+
   rsync -a --delete "$SOURCE_DIR/admin/" "$INSTALL_DIR/admin/"
   info "  Admin panel updated."
 

update_status.go

@@ -0,0 +1,259 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"net/url"
+	"os"
+	"os/exec"
+	"runtime/debug"
+	"strings"
+	"sync"
+	"time"
+)
+
+const (
+	defaultUpdateRepoURL = "https://git.dr2.site/penguinehis/DragonCoreSSH-NewWEB.git"
+	defaultUpdateBranch  = "main"
+	updateStatusCacheTTL = 5 * time.Minute
+	updateCheckTimeout   = 12 * time.Second
+)
+
+// These values are injected by install.sh/update.sh with -ldflags. The
+// runtime/debug fallback keeps the endpoint useful for normal git builds.
+var (
+	buildCommit  = ""
+	buildBranch  = ""
+	buildTime    = ""
+	buildRepoURL = ""
+)
+
+type updateStatusResponse struct {
+	Status             string `json:"status"`
+	UpToDate           bool   `json:"up_to_date"`
+	UpdateAvailable    bool   `json:"update_available"`
+	LocalModified      bool   `json:"local_modified"`
+	CurrentCommit      string `json:"current_commit,omitempty"`
+	CurrentCommitShort string `json:"current_commit_short,omitempty"`
+	LatestCommit       string `json:"latest_commit,omitempty"`
+	LatestCommitShort  string `json:"latest_commit_short,omitempty"`
+	Branch             string `json:"branch"`
+	BuildTime          string `json:"build_time,omitempty"`
+	RepoURL            string `json:"repo_url"`
+	RepoWebURL         string `json:"repo_web_url"`
+	CheckedAt          string `json:"checked_at"`
+	Cached             bool   `json:"cached"`
+	Error              string `json:"error,omitempty"`
+}
+
+var updateStatusCache struct {
+	sync.Mutex
+	checkedAt time.Time
+	response  updateStatusResponse
+}
+
+func handleUpdateStatus(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Cache-Control", "no-store")
+
+	if r.Method != http.MethodGet {
+		w.WriteHeader(http.StatusMethodNotAllowed)
+		_ = json.NewEncoder(w).Encode(map[string]string{"error": "method not allowed"})
+		return
+	}
+
+	force := r.URL.Query().Get("refresh") == "1"
+	resp := getUpdateStatus(r.Context(), force)
+	_ = json.NewEncoder(w).Encode(resp)
+}
+
+func getUpdateStatus(parent context.Context, force bool) updateStatusResponse {
+	updateStatusCache.Lock()
+	defer updateStatusCache.Unlock()
+
+	if !force && !updateStatusCache.checkedAt.IsZero() && time.Since(updateStatusCache.checkedAt) < updateStatusCacheTTL {
+		resp := updateStatusCache.response
+		resp.Cached = true
+		return resp
+	}
+
+	resp := checkRemoteUpdate(parent)
+	updateStatusCache.checkedAt = time.Now()
+	updateStatusCache.response = resp
+	return resp
+}
+
+func checkRemoteUpdate(parent context.Context) updateStatusResponse {
+	repoURL := firstNonEmpty(
+		strings.TrimSpace(os.Getenv("DRAGON_UPDATE_REPO_URL")),
+		readSingleLineFile("/opt/sshpanel/.installed_repo_url"),
+		strings.TrimSpace(buildRepoURL),
+		defaultUpdateRepoURL,
+	)
+	branch := firstNonEmpty(
+		strings.TrimSpace(os.Getenv("DRAGON_UPDATE_BRANCH")),
+		strings.TrimSpace(buildBranch),
+		readSingleLineFile("/opt/sshpanel/.installed_branch"),
+		defaultUpdateBranch,
+	)
+	currentCommit, localModified, resolvedBuildTime := resolveCurrentBuildInfo()
+	if resolvedBuildTime == "" {
+		resolvedBuildTime = readSingleLineFile("/opt/sshpanel/.installed_build_time")
+	}
+	if currentCommit == "" {
+		currentCommit = normalizeGitCommit(readSingleLineFile("/opt/sshpanel/.installed_commit"))
+	}
+
+	now := time.Now().UTC().Format(time.RFC3339)
+	resp := updateStatusResponse{
+		Status:             "unknown",
+		CurrentCommit:      currentCommit,
+		CurrentCommitShort: shortCommit(currentCommit),
+		Branch:             branch,
+		BuildTime:          resolvedBuildTime,
+		RepoURL:            safeRepoURL(repoURL),
+		RepoWebURL:         repoWebURL(repoURL),
+		CheckedAt:          now,
+		LocalModified:      localModified,
+	}
+
+	ctx, cancel := context.WithTimeout(parent, updateCheckTimeout)
+	defer cancel()
+
+	latestCommit, err := queryRemoteCommit(ctx, repoURL, branch)
+	if err != nil {
+		if errors.Is(ctx.Err(), context.DeadlineExceeded) {
+			resp.Error = "remote update check timed out"
+		} else {
+			resp.Error = "could not read the remote Git branch"
+		}
+		return resp
+	}
+
+	resp.LatestCommit = latestCommit
+	resp.LatestCommitShort = shortCommit(latestCommit)
+
+	if currentCommit == "" {
+		resp.Error = "current build commit is unavailable"
+		return resp
+	}
+
+	resp.Status, resp.UpToDate, resp.UpdateAvailable = classifyUpdateStatus(currentCommit, latestCommit, localModified)
+	return resp
+}
+
+func classifyUpdateStatus(currentCommit, latestCommit string, localModified bool) (status string, upToDate bool, updateAvailable bool) {
+	if currentCommit == "" || latestCommit == "" {
+		return "unknown", false, false
+	}
+	if strings.EqualFold(currentCommit, latestCommit) {
+		if localModified {
+			return "local_changes", false, false
+		}
+		return "up_to_date", true, false
+	}
+	return "update_available", false, true
+}
+
+func queryRemoteCommit(ctx context.Context, repoURL, branch string) (string, error) {
+	cmd := exec.CommandContext(ctx, "git", "ls-remote", "--exit-code", "--heads", repoURL, "refs/heads/"+branch)
+	cmd.Env = append(os.Environ(),
+		"GIT_TERMINAL_PROMPT=0",
+		"GIT_ASKPASS=/bin/false",
+	)
+	out, err := cmd.Output()
+	if err != nil {
+		return "", err
+	}
+	fields := strings.Fields(string(out))
+	if len(fields) < 2 {
+		return "", errors.New("invalid git ls-remote response")
+	}
+	commit := normalizeGitCommit(fields[0])
+	if commit == "" {
+		return "", errors.New("invalid remote commit")
+	}
+	return commit, nil
+}
+
+func resolveCurrentBuildInfo() (commit string, modified bool, builtAt string) {
+	commit = normalizeGitCommit(buildCommit)
+	builtAt = strings.TrimSpace(buildTime)
+
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return commit, false, builtAt
+	}
+	for _, setting := range info.Settings {
+		switch setting.Key {
+		case "vcs.revision":
+			if commit == "" {
+				commit = normalizeGitCommit(setting.Value)
+			}
+		case "vcs.modified":
+			modified = strings.EqualFold(setting.Value, "true")
+		case "vcs.time":
+			if builtAt == "" {
+				builtAt = strings.TrimSpace(setting.Value)
+			}
+		}
+	}
+	return commit, modified, builtAt
+}
+
+func normalizeGitCommit(value string) string {
+	value = strings.TrimSpace(value)
+	if strings.EqualFold(value, "unknown") || len(value) < 7 || len(value) > 64 {
+		return ""
+	}
+	for _, r := range value {
+		if !((r >= '0' && r <= '9') || (r >= 'a' && r <= 'f') || (r >= 'A' && r <= 'F')) {
+			return ""
+		}
+	}
+	return strings.ToLower(value)
+}
+
+func shortCommit(commit string) string {
+	if len(commit) <= 12 {
+		return commit
+	}
+	return commit[:12]
+}
+
+func readSingleLineFile(path string) string {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return ""
+	}
+	line := strings.TrimSpace(string(data))
+	if idx := strings.IndexByte(line, '\n'); idx >= 0 {
+		line = strings.TrimSpace(line[:idx])
+	}
+	return line
+}
+
+func firstNonEmpty(values ...string) string {
+	for _, value := range values {
+		if strings.TrimSpace(value) != "" {
+			return strings.TrimSpace(value)
+		}
+	}
+	return ""
+}
+
+func safeRepoURL(raw string) string {
+	u, err := url.Parse(strings.TrimSpace(raw))
+	if err != nil {
+		return strings.TrimSpace(raw)
+	}
+	u.User = nil
+	return u.String()
+}
+
+func repoWebURL(raw string) string {
+	value := safeRepoURL(raw)
+	return strings.TrimSuffix(value, ".git")
+}

update_status_test.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+)
+
+func TestNormalizeGitCommit(t *testing.T) {
+	valid := "CF49340B9A1234567890ABCDEF1234567890ABCD"
+	got := normalizeGitCommit(valid)
+	want := "cf49340b9a1234567890abcdef1234567890abcd"
+	if got != want {
+		t.Fatalf("normalizeGitCommit() = %q, want %q", got, want)
+	}
+	for _, value := range []string{"", "unknown", "xyz1234", "123 4567", "123456"} {
+		if got := normalizeGitCommit(value); got != "" {
+			t.Fatalf("normalizeGitCommit(%q) = %q, want empty", value, got)
+		}
+	}
+}
+
+func TestClassifyUpdateStatus(t *testing.T) {
+	const current = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+	const latest = "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb"
+
+	status, upToDate, updateAvailable := classifyUpdateStatus(current, current, false)
+	if status != "up_to_date" || !upToDate || updateAvailable {
+		t.Fatalf("same clean commit classified as %q, upToDate=%v updateAvailable=%v", status, upToDate, updateAvailable)
+	}
+
+	status, upToDate, updateAvailable = classifyUpdateStatus(current, current, true)
+	if status != "local_changes" || upToDate || updateAvailable {
+		t.Fatalf("modified commit classified as %q, upToDate=%v updateAvailable=%v", status, upToDate, updateAvailable)
+	}
+
+	status, upToDate, updateAvailable = classifyUpdateStatus(current, latest, false)
+	if status != "update_available" || upToDate || !updateAvailable {
+		t.Fatalf("different commit classified as %q, upToDate=%v updateAvailable=%v", status, upToDate, updateAvailable)
+	}
+}
+
+func TestRepoWebURLRemovesCredentialsAndGitSuffix(t *testing.T) {
+	got := repoWebURL("https://user:secret@git.example.test/owner/repo.git")
+	want := "https://git.example.test/owner/repo"
+	if got != want {
+		t.Fatalf("repoWebURL() = %q, want %q", got, want)
+	}
+}
+
+func TestQueryRemoteCommit(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("shell-script git stub is Unix-specific")
+	}
+	const want = "cf49340b9a1234567890abcdef1234567890abcd"
+	dir := t.TempDir()
+	gitPath := filepath.Join(dir, "git")
+	script := "#!/bin/sh\nprintf '%s\\trefs/heads/main\\n' '" + want + "'\n"
+	if err := os.WriteFile(gitPath, []byte(script), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	t.Setenv("PATH", dir+string(os.PathListSeparator)+os.Getenv("PATH"))
+
+	got, err := queryRemoteCommit(context.Background(), "https://git.example.test/owner/repo.git", "main")
+	if err != nil {
+		t.Fatalf("queryRemoteCommit() error = %v", err)
+	}
+	if got != want {
+		t.Fatalf("queryRemoteCommit() = %q, want %q", got, want)
+	}
+}