add battery charge monitoring

beszel/internal/agent/battery.go

@@ -0,0 +1,18 @@
+package agent
+
+import "github.com/distatus/battery"
+
+// getBatteryStats returns the current battery percent and charge state
+func getBatteryStats() (batteryPercent uint8, batteryState uint8, err error) {
+	bat, err := battery.Get(0)
+	if err != nil {
+		return batteryPercent, batteryState, err
+	}
+	full := bat.Design
+	if full == 0 {
+		full = bat.Full
+	}
+	batteryPercent = uint8(bat.Current / full * 100)
+	batteryState = uint8(bat.State.Raw)
+	return batteryPercent, batteryState, nil
+}