fixup! Skip metrics when standby JSON cached

Describe now exports a static superset of descriptors to avoid unregistered descriptor errors when metrics are conditionally skipped.

Author: yonran

main.go

@@ -57,7 +57,9 @@ type SMARTctlManagerCollector struct {
 
 // Describe sends the super-set of all possible descriptors of metrics
 func (i *SMARTctlManagerCollector) Describe(ch chan<- *prometheus.Desc) {
-	prometheus.DescribeByCollect(i, ch)
+	for _, desc := range allMetricDescs {
+		ch <- desc
+	}
 }
 
 // Collect is called by the Prometheus registry when collecting metrics.

metrics.go

@@ -362,4 +362,45 @@ var (
 		},
 		nil,
 	)
+	allMetricDescs = []*prometheus.Desc{
+		metricSmartctlVersion,
+		metricDeviceModel,
+		metricDeviceCount,
+		metricDeviceCapacityBlocks,
+		metricDeviceCapacityBytes,
+		metricDeviceTotalCapacityBytes,
+		metricDeviceBlockSize,
+		metricDeviceInterfaceSpeed,
+		metricDeviceAttribute,
+		metricDevicePowerOnSeconds,
+		metricDeviceRotationRate,
+		metricDeviceTemperature,
+		metricDevicePowerCycleCount,
+		metricDevicePercentageUsed,
+		metricDeviceAvailableSpare,
+		metricDeviceAvailableSpareThreshold,
+		metricDeviceCriticalWarning,
+		metricDeviceMediaErrors,
+		metricDeviceNumErrLogEntries,
+		metricDeviceBytesRead,
+		metricDeviceBytesWritten,
+		metricDeviceSmartStatus,
+		metricDeviceExitStatus,
+		metricDeviceState,
+		metricDevicePowerMode,
+		metricDeviceStatistics,
+		metricDeviceErrorLogCount,
+		metricDeviceSelfTestLogCount,
+		metricDeviceSelfTestLogErrorCount,
+		metricDeviceERCSeconds,
+		metricSCSIGrownDefectList,
+		metricReadErrorsCorrectedByRereadsRewrites,
+		metricReadErrorsCorrectedByEccFast,
+		metricReadErrorsCorrectedByEccDelayed,
+		metricReadTotalUncorrectedErrors,
+		metricWriteErrorsCorrectedByRereadsRewrites,
+		metricWriteErrorsCorrectedByEccFast,
+		metricWriteErrorsCorrectedByEccDelayed,
+		metricWriteTotalUncorrectedErrors,
+	}
 )