node exporter: add hostname dependent docker count and default value for smartd script

network/node-exporter-smartmon.sh

@@ -11,7 +11,12 @@ for dev in $(smartctl --scan-open | awk '{print $1}'); do
         | head -1 \
         | awk '{print $(NF-1)}')
 
-    echo $name: $LAST
     # Skip devices without self-test history
+    if [[ "${LAST}" == "-" ]]; then
+        HOURS=$(smartctl -a "$DEV" 2>/dev/null | awk '/Power_On_Hours/ {print $10}')
+        LAST=${HOURS:- -1} 
+    fi
+    echo $name: $LAST
     echo "smart_last_selftest_poweron_hours{device=\"$name\"} $LAST" >> "$OUT"
+
 done