feat: Interface-Durchsatz-Chart — Backend berechnet RX/TX-Rate (bps), Frontend zeigt Dual-Sparkline per Klick auf Interface

backend/db/postgres.go

@@ -15,8 +15,15 @@ import (
 	_ "github.com/jackc/pgx/v5/stdlib"
 )
 
+type ifaceSnapshot struct {
+	rxBytes float64
+	txBytes float64
+	ts      time.Time
+}
+
 type Database struct {
-	db *sql.DB
+	db           *sql.DB
+	lastIfaceSnap map[string]map[string]ifaceSnapshot // agentID -> ifaceName -> snapshot
 }
 
 type DBConfig struct {
@@ -49,7 +56,7 @@ func New(cfg DBConfig) (*Database, error) {
 		return nil, fmt.Errorf("Datenbank-Verbindung fehlgeschlagen: %w", err)
 	}
 
-	d := &Database{db: db}
+	d := &Database{db: db, lastIfaceSnap: make(map[string]map[string]ifaceSnapshot)}
 	if err := d.migrate(); err != nil {
 		return nil, fmt.Errorf("Migration fehlgeschlagen: %w", err)
 	}
@@ -415,13 +422,32 @@ func (d *Database) writeMetrics(tx *sql.Tx, agentID string, ts time.Time, data *
 		}
 	}
 
-	// Network Interfaces
+	// Network Interfaces — kumulierte Bytes + abgeleitete Rate (bytes/s)
+	if _, ok := d.lastIfaceSnap[agentID]; !ok {
+		d.lastIfaceSnap[agentID] = make(map[string]ifaceSnapshot)
+	}
 	for _, iface := range data.NetworkInterfaces {
-		if iface.RxBytes > 0 || iface.TxBytes > 0 {
-			tags, _ := json.Marshal(map[string]string{"interface": iface.Name})
-			stmt.Exec(ts, agentID, "interface_rx_bytes", float64(iface.RxBytes), string(tags))
-			stmt.Exec(ts, agentID, "interface_tx_bytes", float64(iface.TxBytes), string(tags))
+		rx := float64(iface.RxBytes)
+		tx := float64(iface.TxBytes)
+		tags, _ := json.Marshal(map[string]string{"interface": iface.Name})
+		tagsStr := string(tags)
+		if rx > 0 || tx > 0 {
+			stmt.Exec(ts, agentID, "interface_rx_bytes", rx, tagsStr)
+			stmt.Exec(ts, agentID, "interface_tx_bytes", tx, tagsStr)
 		}
+		// Rate berechnen wenn vorheriger Snapshot vorhanden
+		if prev, ok := d.lastIfaceSnap[agentID][iface.Name]; ok {
+			elapsed := ts.Sub(prev.ts).Seconds()
+			if elapsed > 0 && elapsed < 300 { // max 5 min Lücke ignorieren
+				rxRate := (rx - prev.rxBytes) / elapsed
+				txRate := (tx - prev.txBytes) / elapsed
+				if rxRate >= 0 && txRate >= 0 { // negative Werte ignorieren (Reboot)
+					stmt.Exec(ts, agentID, "interface_rx_bps", rxRate, tagsStr)
+					stmt.Exec(ts, agentID, "interface_tx_bps", txRate, tagsStr)
+				}
+			}
+		}
+		d.lastIfaceSnap[agentID][iface.Name] = ifaceSnapshot{rxBytes: rx, txBytes: tx, ts: ts}
 	}
 
 	// PF States
@@ -858,7 +884,7 @@ func (d *Database) DeleteConfigBackup(agentID string, backupID int64) (bool, err
 // --- Metrics Abfragen ---
 
 // GetMetrics holt Metriken fuer einen Agent in einem Zeitraum
-func (d *Database) GetMetrics(agentID, metric string, from, to time.Time, limit int) ([]map[string]interface{}, error) {
+func (d *Database) GetMetrics(agentID, metric, tagsFilter string, from, to time.Time, limit int) ([]map[string]interface{}, error) {
 	if limit <= 0 {
 		limit = 1000
 	}
@@ -872,6 +898,11 @@ func (d *Database) GetMetrics(agentID, metric string, from, to time.Time, limit
 		args = append(args, metric)
 	}
 
+	if tagsFilter != "" {
+		query += fmt.Sprintf(" AND tags @> $%d::jsonb", len(args)+1)
+		args = append(args, tagsFilter)
+	}
+
 	query += " ORDER BY time DESC LIMIT $" + fmt.Sprintf("%d", len(args)+1)
 	args = append(args, limit)