fix: minor changes on update

.claude/settings.local.json

@@ -0,0 +1,15 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(go get *)",
+      "Bash(go build *)",
+      "Bash(go vet *)",
+      "Read(//usr/lib/**)",
+      "Read(//proc/**)",
+      "Bash(systemctl show *)",
+      "Bash(echo \"exit=$?\")",
+      "Bash(systemctl list-units *)",
+      "Bash(go test *)"
+    ]
+  }
+}

cmd/server/server.go

@@ -232,6 +232,8 @@ func runServer() {
 	meta.Register(api, mods)
 	meta.RegisterHealth(api, sessions)
 	meta.RegisterWhoami(api, sessions, roles, mods)
+	meta.ConfigPath = configPath
+	meta.RegisterUpdate(api)
 
 	auth.RegisterLogin(api, sessions, auditStore, cfg.SecureCookie())
 	auth.RegisterLogout(api, sessions, cfg.SecureCookie())

cmd/server/service.go

@@ -425,7 +425,8 @@ Usage:
   nadir token add <name>            Mint a machine credential (Bearer token), shown once
   nadir token rm <name>             Revoke a token (effective immediately, no restart)
   nadir token ls                    List token names and when they were created
-  nadir update                      Fetch the latest release from server.release_repo and restart
+  nadir update [--check|--force]    Fetch the latest release from server.release_repo and restart
+                                    (--check: report only; --force: re-download when already current)
   nadir help                        Show this help
 
 Most commands need root. Config path is specified via -f/--config or CONFIG_PATH (default ~/.config/config.yaml).

cmd/server/update.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"flag"
 	"fmt"
 	"io"
 	"net/http"
@@ -12,6 +13,7 @@ import (
 	"strings"
 	"time"
 
+	"nadir"
 	"nadir/internal/config"
 )
 
@@ -19,7 +21,12 @@ import (
 // releases/latest, pick the asset for the host's GOARCH, atomically replace
 // /usr/local/bin/nadir (or wherever the running binary lives), and restart
 // the systemd unit so the new code takes effect.
-func updateCmd(_ []string) error {
+func updateCmd(args []string) error {
+	fs := flag.NewFlagSet("update", flag.ExitOnError)
+	check := fs.Bool("check", false, "report the latest version without downloading")
+	force := fs.Bool("force", false, "re-download even when already at the latest version")
+	fs.Parse(args)
+
 	configPath, err := resolveConfigPath()
 	if err != nil {
 		return err
@@ -44,6 +51,21 @@ func updateCmd(_ []string) error {
 		return err
 	}
 
+	fmt.Printf("current: %s\nlatest:  %s\n", nadir.Version, rel.TagName)
+	upToDate := nadir.Version == rel.TagName
+	switch {
+	case *check:
+		if upToDate {
+			fmt.Println("already up to date.")
+		} else {
+			fmt.Println("update available; run `nadir update` to install.")
+		}
+		return nil
+	case upToDate && !*force:
+		fmt.Println("already up to date; pass --force to re-download.")
+		return nil
+	}
+
 	var assetURL, assetName string
 	for _, a := range rel.Assets {
 		if strings.HasSuffix(a.Name, suffix) {

internal/meta/update.go

@@ -0,0 +1,63 @@
+package meta
+
+import (
+	"context"
+	"os"
+	"os/exec"
+	"syscall"
+
+	"nadir/internal/config"
+	"nadir/internal/oscmd"
+
+	"github.com/danielgtaylor/huma/v2"
+)
+
+// ConfigPath is set at startup so the update handler can re-load config and
+// surface release_repo / parse errors to the caller instead of only stderr.
+var ConfigPath string
+
+// RegisterUpdate wires POST /api/meta/update. It runs the equivalent of
+// `sudo nadir update` in a detached session and returns 202 immediately; the
+// systemctl restart that ends the updater drops in-flight connections, so the
+// caller should poll /api/health to confirm the new version is up.
+//
+// Authorization: requires (meta, root). Only roles with a wildcard grant
+// (the default admin role) match, since "meta" isn't a real module with a
+// declared permission vocabulary.
+func RegisterUpdate(api huma.API) {
+	huma.Register(api, huma.Operation{
+		OperationID:   "meta-update",
+		Method:        "POST",
+		Path:          "/api/update",
+		Summary:       "Update nadir to the latest release",
+		Description:   "Equivalent to running `sudo nadir update` on the host: queries server.release_repo for the latest release, downloads the binary matching the host's architecture, atomically replaces the running binary, and restarts the systemd unit. Returns 202 immediately; the service restart drops in-flight connections, so poll /api/health to confirm the new version is up. Requires the wildcard admin role.",
+		Tags:          []string{"Meta"},
+		Metadata:      map[string]any{"module": "meta", "permission": "root"},
+		Errors:        []int{400, 401, 403, 500},
+		DefaultStatus: 202,
+	}, func(ctx context.Context, _ *struct{}) (*oscmd.StatusOutput, error) {
+		if ConfigPath != "" {
+			cfg, err := config.Load(ConfigPath)
+			if err != nil {
+				return nil, huma.Error500InternalServerError("config load failed", err)
+			}
+			if cfg.Server.ReleaseRepo == "" {
+				return nil, huma.Error400BadRequest("server.release_repo not set in " + ConfigPath)
+			}
+		}
+		exe, err := os.Executable()
+		if err != nil {
+			return nil, huma.Error500InternalServerError("could not resolve own binary path", err)
+		}
+		cmd := exec.Command(exe, "update")
+		// Detach from the server's process group so `systemctl restart nadir`
+		// (the final step of `nadir update`) doesn't kill its own updater.
+		cmd.SysProcAttr = &syscall.SysProcAttr{Setsid: true}
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		if err := cmd.Start(); err != nil {
+			return nil, huma.Error500InternalServerError("could not start updater", err)
+		}
+		return oscmd.OK(), nil
+	})
+}

internal/modules/system/info.go

@@ -159,9 +159,18 @@ func cpuInfo() CPUInfo {
 	c := CPUInfo{Model: cpuModel(string(data)), LogicalCPUs: runtime.NumCPU()}
 	c.MinMHz, c.MaxMHz, c.CurrentMHz = cpuFreqMHz("/sys/devices/system/cpu")
 	// ponytail: cpufreq sysfs is absent on many VMs and stock Ubuntu server
-	// kernels; fall back to /proc/cpuinfo "cpu MHz" so CurrentMHz isn't 0.
+	// kernels; fall back to /proc/cpuinfo "cpu MHz" — VMs have a fixed clock,
+	// so min == max == cur is the honest answer.
+	if mhz := cpuinfoMaxMHz(string(data)); mhz > 0 {
 		if c.CurrentMHz == 0 {
-		c.CurrentMHz = cpuinfoMaxMHz(string(data))
+			c.CurrentMHz = mhz
+		}
+		if c.MaxMHz == 0 {
+			c.MaxMHz = mhz
+		}
+		if c.MinMHz == 0 {
+			c.MinMHz = mhz
+		}
 	}
 	return c
 }