nvme_metrics.py: use device basename instead of full path

Avoid breaking label convention of nvme_metrics.sh, which uses just the
device basename, e.g. "nvme0n1" instead of "/dev/nvme0n1".

Author: dswarbrick

nvme_metrics.py

@@ -158,47 +158,48 @@ def main():
 
     for device in device_list["Devices"]:
         device_path = device["DevicePath"]
+        device_name = os.path.basename(device_path)
 
         metrics["device_info"].labels(
-            device_path,
+            device_name,
             device["ModelNumber"],
             device["Firmware"],
             device["SerialNumber"].strip(),
         )
 
-        metrics["sector_size"].labels(device_path).set(device["SectorSize"])
-        metrics["physical_size"].labels(device_path).set(device["PhysicalSize"])
-        metrics["used_bytes"].labels(device_path).set(device["UsedBytes"])
+        metrics["sector_size"].labels(device_name).set(device["SectorSize"])
+        metrics["physical_size"].labels(device_name).set(device["PhysicalSize"])
+        metrics["used_bytes"].labels(device_name).set(device["UsedBytes"])
 
         smart_log = exec_nvme_json("smart-log", device_path)
 
         # Various counters in the NVMe specification are 128-bit, which would have to discard
         # resolution if converted to a JSON number (i.e., float64_t). Instead, nvme-cli marshals
         # them as strings. As such, they need to be explicitly cast to int or float when using them
         # in Counter metrics.
-        metrics["data_units_read"].labels(device_path).inc(int(smart_log["data_units_read"]))
-        metrics["data_units_written"].labels(device_path).inc(int(smart_log["data_units_written"]))
-        metrics["host_read_commands"].labels(device_path).inc(int(smart_log["host_read_commands"]))
-        metrics["host_write_commands"].labels(device_path).inc(
+        metrics["data_units_read"].labels(device_name).inc(int(smart_log["data_units_read"]))
+        metrics["data_units_written"].labels(device_name).inc(int(smart_log["data_units_written"]))
+        metrics["host_read_commands"].labels(device_name).inc(int(smart_log["host_read_commands"]))
+        metrics["host_write_commands"].labels(device_name).inc(
             int(smart_log["host_write_commands"])
         )
-        metrics["avail_spare"].labels(device_path).set(smart_log["avail_spare"] / 100)
-        metrics["spare_thresh"].labels(device_path).set(smart_log["spare_thresh"] / 100)
-        metrics["percent_used"].labels(device_path).set(smart_log["percent_used"] / 100)
-        metrics["critical_warning"].labels(device_path).set(smart_log["critical_warning"])
-        metrics["media_errors"].labels(device_path).inc(int(smart_log["media_errors"]))
-        metrics["num_err_log_entries"].labels(device_path).inc(
+        metrics["avail_spare"].labels(device_name).set(smart_log["avail_spare"] / 100)
+        metrics["spare_thresh"].labels(device_name).set(smart_log["spare_thresh"] / 100)
+        metrics["percent_used"].labels(device_name).set(smart_log["percent_used"] / 100)
+        metrics["critical_warning"].labels(device_name).set(smart_log["critical_warning"])
+        metrics["media_errors"].labels(device_name).inc(int(smart_log["media_errors"]))
+        metrics["num_err_log_entries"].labels(device_name).inc(
             int(smart_log["num_err_log_entries"])
         )
-        metrics["power_cycles"].labels(device_path).inc(int(smart_log["power_cycles"]))
-        metrics["power_on_hours"].labels(device_path).inc(int(smart_log["power_on_hours"]))
-        metrics["controller_busy_time"].labels(device_path).inc(
+        metrics["power_cycles"].labels(device_name).inc(int(smart_log["power_cycles"]))
+        metrics["power_on_hours"].labels(device_name).inc(int(smart_log["power_on_hours"]))
+        metrics["controller_busy_time"].labels(device_name).inc(
             int(smart_log["controller_busy_time"])
         )
-        metrics["unsafe_shutdowns"].labels(device_path).inc(int(smart_log["unsafe_shutdowns"]))
+        metrics["unsafe_shutdowns"].labels(device_name).inc(int(smart_log["unsafe_shutdowns"]))
 
         # NVMe reports temperature in kelvins; convert it to degrees Celsius.
-        metrics["temperature"].labels(device_path).set(smart_log["temperature"] - 273)
+        metrics["temperature"].labels(device_name).set(smart_log["temperature"] - 273)
 
 
 if __name__ == "__main__":