feat: labels map en config (role) → extra_label en métricas + stream labels en logs

config.go

@@ -16,6 +16,9 @@ type Config struct {
 	User        string `json:"user"`         // basic-auth user, shared by metrics and logs (empty disables auth)
 	Pass        string `json:"pass"`         // basic-auth password
 	IntervalSec int    `json:"interval_sec"` // metrics push period in seconds (default 15)
+	// Extra labels attached to every metric series and log stream of this node,
+	// e.g. {"role": "vps"}. Enables filtering in Grafana (per-role dashboards).
+	Labels map[string]string `json:"labels"`
 	// Android/Termux exec workaround: the standard Go binary cannot exec
 	// subprocesses there (seccomp blocks pidfd_open with SIGSYS). When set, the
 	// agent reads battery JSON from this file (written by a shell helper) instead
@@ -81,3 +84,17 @@ func loadConfig(path string) (Config, error) {
 	}
 	return cfg, nil
 }
+
+// extraLabels returns the labels attached to every series/stream: the node's
+// instance plus any custom labels (e.g. role). The optional extra map is merged
+// last (used to add per-stream labels like job/unit for logs).
+func (cfg Config) extraLabels(extra map[string]string) map[string]string {
+	m := map[string]string{"instance": cfg.Node}
+	for k, v := range cfg.Labels {
+		m[k] = v
+	}
+	for k, v := range extra {
+		m[k] = v
+	}
+	return m
+}

logs.go

@@ -159,7 +159,7 @@ func shipJournald(ctx context.Context, cfg Config, binPath string) {
 				ts[i] = it.ts
 				ln[i] = it.line
 			}
-			labels := map[string]string{"instance": cfg.Node, "job": "journald", "unit": unit}
+			labels := cfg.extraLabels(map[string]string{"job": "journald", "unit": unit})
 			if err := infra.PushLokiStream(cfg.LokiURL, cfg.User, cfg.Pass, labels, ts, ln); err != nil {
 				log.Printf("logs: push error (unit=%s, %d lines): %v", unit, len(items), err)
 			}
@@ -195,7 +195,7 @@ func shipFileTail(ctx context.Context, cfg Config, path, job string) {
 	if fi, err := os.Stat(path); err == nil {
 		offset = fi.Size() // skip pre-existing history on first start
 	}
-	labels := map[string]string{"instance": cfg.Node, "job": job}
+	labels := cfg.extraLabels(map[string]string{"job": job})
 
 	ticker := time.NewTicker(3 * time.Second)
 	defer ticker.Stop()

main.go

@@ -130,7 +130,7 @@ func pushOnce(cfg Config) error {
 	// cfg.BatteryFile and we parse that here; elsewhere we collect directly.
 	samples = append(samples, batterySamples(cfg)...)
 	body := infra.FormatPromExposition(samples, time.Now().UnixMilli())
-	if err := infra.PushPromRemote(cfg.HubURL, cfg.User, cfg.Pass, body, map[string]string{"instance": cfg.Node}); err != nil {
+	if err := infra.PushPromRemote(cfg.HubURL, cfg.User, cfg.Pass, body, cfg.extraLabels(nil)); err != nil {
 		return err
 	}
 	log.Printf("pushed %d samples", len(samples))