check_nvme_health: Add NVMe disk remaining life check

Discovers NVMe devices via /sys/class/nvme and queries percent_used from
nvme-cli smart-log to report remaining drive life. Raises WARNING at <=20%
and CRITICAL at <=10% remaining life (configurable via -w/-c).

Author: lamaral

src/check_nvme_health.py

@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+"""InnoGames Monitoring Plugins - NVMe Health Check
+
+This script checks the health of NVMe disks by discovering devices via sysfs
+and querying SMART data with nvme-cli. It raises a warning or critical state
+when the remaining life falls below the configured thresholds.
+
+Copyright (c) 2026 InnoGames GmbH
+"""
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+import json
+import os
+import sys
+from argparse import ArgumentParser
+from subprocess import CalledProcessError, STDOUT, check_output
+
+
+class ExitCodes():
+    OK = 0
+    WARNING = 1
+    CRITICAL = 2
+    UNKNOWN = 3
+
+    @classmethod
+    def label(cls, code):
+        return {cls.OK: 'OK', cls.WARNING: 'WARNING', cls.CRITICAL: 'CRITICAL', cls.UNKNOWN: 'UNKNOWN'}[code]
+
+
+def parse_args():
+    parser = ArgumentParser(
+        description='Check NVMe disk remaining life via nvme-cli smart-log',
+    )
+    parser.add_argument(
+        '--warning', '-w',
+        help='warning threshold for remaining life percentage (default: 20)',
+        default=20,
+        type=int,
+    )
+    parser.add_argument(
+        '--critical', '-c',
+        help='critical threshold for remaining life percentage (default: 10)',
+        default=10,
+        type=int,
+    )
+    return parser.parse_args()
+
+
+def main():
+    args = parse_args()
+
+    devices = get_nvme_devices()
+    if not devices:
+        print('UNKNOWN - No NVMe devices found in /sys/class/nvme')
+        sys.exit(ExitCodes.UNKNOWN)
+
+    code = ExitCodes.OK
+    summaries = []
+    perfdata = []
+
+    for device in devices:
+        name = os.path.basename(device)
+
+        try:
+            smart = get_smart_log(device)
+        except CalledProcessError as e:
+            print(f'UNKNOWN - Failed to query {device}: {e.output.decode().strip()}')
+            sys.exit(ExitCodes.UNKNOWN)
+        except (OSError, ValueError) as e:
+            print(f'UNKNOWN - Error reading {device}: {e}')
+            sys.exit(ExitCodes.UNKNOWN)
+
+        percent_used = smart.get('percent_used')
+        if percent_used is None:
+            print(f'UNKNOWN - percent_used missing in smart-log output for {device}')
+            sys.exit(ExitCodes.UNKNOWN)
+
+        remaining = 100 - percent_used
+
+        if remaining <= args.critical:
+            code = max(code, ExitCodes.CRITICAL)
+        elif remaining <= args.warning:
+            code = max(code, ExitCodes.WARNING)
+
+        summaries.append(f'{name} life={remaining}%')
+        perfdata.append(f'{name}_life={remaining}%;{args.warning};{args.critical};0;100')
+
+    status = ExitCodes.label(code)
+    if len(summaries) == 1:
+        lines = [f'{status} - {summaries[0]} | {perfdata[0]}']
+    else:
+        lines = [status]
+        for summary in summaries[:-1]:
+            lines.append(summary)
+        lines.append(f'{summaries[-1]} | {perfdata[0]}')
+        for perf in perfdata[1:]:
+            lines.append(perf)
+    print('\n'.join(lines))
+    sys.exit(code)
+
+
+def get_nvme_devices():
+    """Return sorted list of /dev/nvmeN device paths discovered via sysfs"""
+    sysfs_path = '/sys/class/nvme'
+    if not os.path.exists(sysfs_path):
+        return []
+    return sorted('/dev/' + entry for entry in os.listdir(sysfs_path))
+
+
+def get_smart_log(device):
+    """Run nvme smart-log on device and return parsed JSON dict"""
+    raw = check_output(
+        ['nvme', 'smart-log', '--output-format=json', device],
+        stderr=STDOUT,
+    )
+    return json.loads(raw.decode())
+
+
+if __name__ == '__main__':
+    main()