Added deviceCount

Removed Unsupported messages as prometheus fails on that.

nvidia_smi_exporter.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"os"
 	"os/exec"
+	"strconv"
 	"strings"
 )
 
@@ -39,13 +40,21 @@ func metrics(response http.ResponseWriter, request *http.Request) {
 		"utilization.memory", "memory.total", "memory.free", "memory.used", "eccerrorsaggregate.total", "eccuncorrectedvolatile.total"}
 
 	result := ""
+	max_id := ""
 	for _, row := range records {
 		name := fmt.Sprintf("%s[%s]", row[0], row[1])
 		for idx, value := range row[2:] {
 			result = fmt.Sprintf(
 				"%s%s{gpu=\"%s\"} %s\n", result,
 				metricList[idx], name, value)
+			max_id = row[1]
 		}
+		deviceCount := 0
+		deviceCount, err = strconv.Atoi(max_id)
+		result = fmt.Sprintf(
+			"%sdeviceCount %d\n", result, deviceCount+1)
+		result = strings.Replace(result, "[Not Supported]", "-1", -1)
+
 	}
 
 	fmt.Fprintf(response, strings.Replace(result, ".", "_", -1))