Automatically load the available devices

main.go

@@ -36,6 +36,17 @@ func (i SMARTctlManagerCollector) Collect(ch chan<- prometheus.Metric) {
 
 func init() {
 	options = loadOptions()
+
+	if len(options.SMARTctl.Devices) == 0 {
+		logger.Debug("No devices specified, trying to load them automatically")
+		json := readSMARTctlDevices()
+		devices := json.Get("devices").Array()
+		for _, d := range devices {
+			device := d.Get("name").String()
+			logger.Debug("Found device: %s", device)
+			options.SMARTctl.Devices = append(options.SMARTctl.Devices, device)
+		}
+	}
 }
 
 func main() {

readjson.go

@@ -55,6 +55,15 @@ func readSMARTctl(device string) gjson.Result {
 	return parseJSON(string(out))
 }
 
+func readSMARTctlDevices() gjson.Result {
+	logger.Debug("Collecting devices")
+	out, err := exec.Command(options.SMARTctl.SMARTctlLocation, "--json", "--scan-open").Output()
+	if err != nil {
+		logger.Warning("S.M.A.R.T. output reading error: %s", err)
+	}
+	return parseJSON(string(out))
+}
+
 // Select json source and parse
 func readData(device string) gjson.Result {
 	if options.SMARTctl.FakeJSON {

smartctl_exporter.yaml

@@ -4,8 +4,8 @@ smartctl_exporter:
   fake_json: no
   smartctl_location: /usr/sbin/smartctl
   collect_not_more_than_period: 20s
-  devices:
-  - /dev/nvme0
-  - /dev/nvme1
-  - /dev/nvme2
-  - /dev/nvme3
+#  devices:
+#  - /dev/nvme0
+#  - /dev/nvme1
+#  - /dev/nvme2
+#  - /dev/nvme3