Start the Go rewrite: jsjson, awg-ctrl port, differential bench

- internal/jsjson: JSON.stringify-compatible encoder and order-preserving decoder,
  tested against fixtures produced by Node itself
- internal/ctrl: awg-ctrl in Go (params, vpn:// keys, users, peers, sync, 3.1
  upgrade, CAKE shaping, metrics, monitor job, Express-compatible HTTP layer)
- internal/iauth, internal/logx: internal Ed25519 tokens and logging
- tools/diffbench: Docker bench with stubbed awg/ip/tc/nft that runs one scenario
  against the TS and Go implementations for comparison

internal/ctrl/metrics.go

@@ -0,0 +1,183 @@
+package ctrl
+
+import (
+	"os"
+	"regexp"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+// Метрики для Prometheus. awg-ctrl отдаёт JSON, а текстовый формат собирает awg-ui: на ноде
+// агент пропускает только /api/*, и один формат на ядре и нодах проще сверять. Кэш на 5 с —
+// несколько скрейперов не должны гонять `awg show` чаще.
+const metricsTTL = 5 * time.Second
+
+type metricsCache struct {
+	mu   sync.Mutex
+	at   time.Time
+	data any
+}
+
+type metricsPeer struct {
+	Kind     string  `json:"kind"`
+	Name     string  `json:"name"`
+	IP       string  `json:"ip"`
+	Online   bool    `json:"online"`
+	Rx       float64 `json:"rx"`
+	Tx       float64 `json:"tx"`
+	Priority string  `json:"priority"`
+}
+
+type metricsHost struct {
+	CPU   map[string]float64 `json:"cpu"`
+	Cores int                `json:"cores"`
+	Load  []float64          `json:"load"`
+	Mem   struct {
+		Total     float64 `json:"total"`
+		Available float64 `json:"available"`
+	} `json:"mem"`
+}
+
+type linkStats struct {
+	RxBytes   float64 `json:"rx_bytes"`
+	TxBytes   float64 `json:"tx_bytes"`
+	RxPackets float64 `json:"rx_packets"`
+	TxPackets float64 `json:"tx_packets"`
+	RxDropped float64 `json:"rx_dropped"`
+	TxDropped float64 `json:"tx_dropped"`
+	RxErrors  float64 `json:"rx_errors"`
+	TxErrors  float64 `json:"tx_errors"`
+}
+
+type metricsBody struct {
+	Up    bool   `json:"up"`
+	Gen   string `json:"gen"`
+	Peers struct {
+		Total  int `json:"total"`
+		Online int `json:"online"`
+	} `json:"peers"`
+	RxBytes float64       `json:"rx_bytes"`
+	TxBytes float64       `json:"tx_bytes"`
+	Link    linkStats     `json:"link"`
+	Shaping ShapingStatus `json:"shaping"`
+	Host    *metricsHost  `json:"host"`
+	List    []metricsPeer `json:"list"`
+}
+
+func (s *Server) linkCounter(name string) float64 {
+	b, err := os.ReadFile("/sys/class/net/" + s.iface + "/statistics/" + name)
+	if err != nil {
+		return 0
+	}
+	return orZero(jsNumber(string(b)))
+}
+
+var cpuModes = []string{"user", "nice", "system", "idle", "iowait", "irq", "softirq", "steal"}
+
+// readHost: нагрузка хоста из /proc. Счётчики CPU кумулятивные (секунды по режимам, как у
+// node_exporter): долю считает Prometheus через rate(). Память — MemAvailable, а не MemFree:
+// кэш ядра свободен.
+func readHost() *metricsHost {
+	stat, err := os.ReadFile("/proc/stat")
+	if err != nil {
+		return nil
+	}
+	first := strings.Fields(strings.SplitN(string(stat), "\n", 2)[0])
+	if len(first) < 2 {
+		return nil
+	}
+	h := &metricsHost{CPU: map[string]float64{}, Cores: runtime.NumCPU()}
+	for i, m := range cpuModes {
+		v := 0.0
+		if i+1 < len(first) {
+			v = orZero(jsNumber(first[i+1]))
+		}
+		h.CPU[m] = v / 100 // USER_HZ = 100 на всех обычных ядрах
+	}
+	mem, err := os.ReadFile("/proc/meminfo")
+	if err != nil {
+		return nil
+	}
+	kb := func(k string) float64 {
+		m := regexp.MustCompile(`(?m)^` + k + `:\s+(\d+) kB`).FindStringSubmatch(string(mem))
+		if m == nil {
+			return 0
+		}
+		f, _ := strconv.ParseFloat(m[1], 64)
+		return f * 1024
+	}
+	h.Mem.Total, h.Mem.Available = kb("MemTotal"), kb("MemAvailable")
+	if la, err := os.ReadFile("/proc/loadavg"); err == nil {
+		f := strings.Fields(string(la))
+		for i := 0; i < 3 && i < len(f); i++ {
+			h.Load = append(h.Load, orZero(jsNumber(f[i])))
+		}
+	}
+	return h
+}
+
+func (s *Server) collectMetrics() (*metricsBody, error) {
+	st := s.interfaceStatus()
+	stats := map[string]peerStat{}
+	if st.Up {
+		stats = s.getPeersData()
+	}
+	rows, err := s.db.Query("SELECT name, ip, pub_key FROM users WHERE vpn_key != ''")
+	if err != nil {
+		return nil, err
+	}
+	b := &metricsBody{Up: st.Up, Gen: s.cfg().Gen, List: []metricsPeer{}}
+	for rows.Next() {
+		var n, ip, pub string
+		if err := rows.Scan(&n, &ip, &pub); err != nil {
+			rows.Close()
+			return nil, err
+		}
+		ps := stats[pub]
+		b.List = append(b.List, metricsPeer{"user", n, ip, ps.Online, orZero(ps.Rx), orZero(ps.Tx), s.shaping.PriorityOf(ip)})
+	}
+	rows.Close()
+	devs, err := s.peersAll()
+	if err != nil {
+		return nil, err
+	}
+	for _, p := range devs {
+		ps := stats[p.PubKey]
+		b.List = append(b.List, metricsPeer{"device", "", p.IP, ps.Online, orZero(ps.Rx), orZero(ps.Tx), s.shaping.PriorityOf(p.IP)})
+	}
+	b.Peers.Total = st.Peers
+	for _, ps := range stats {
+		if ps.Online {
+			b.Peers.Online++
+		}
+		b.RxBytes += orZero(ps.Rx)
+		b.TxBytes += orZero(ps.Tx)
+	}
+	b.Link = linkStats{
+		s.linkCounter("rx_bytes"), s.linkCounter("tx_bytes"), s.linkCounter("rx_packets"), s.linkCounter("tx_packets"),
+		s.linkCounter("rx_dropped"), s.linkCounter("tx_dropped"), s.linkCounter("rx_errors"), s.linkCounter("tx_errors"),
+	}
+	b.Shaping = s.shaping.Status()
+	b.Host = readHost()
+	return b, nil
+}
+
+// metricsCached отдаёт кэш на metricsTTL; ошибку не кэшируем.
+func (s *Server) metricsCached() (any, error) {
+	m := &s.metrics
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if m.data != nil && time.Since(m.at) <= metricsTTL {
+		return m.data, nil
+	}
+	d, err := s.collectMetrics()
+	if err != nil {
+		m.data = nil
+		return nil, err
+	}
+	m.at, m.data = time.Now(), d
+	return d, nil
+}