smartmon: scan smartd.conf for additonal devices

Pick only -d from all disk options, if present

roles/base/files/node-exporter-scripts/smartmon.py

@@ -4,6 +4,7 @@ import collections
 import csv
 import datetime
 import decimal
+import itertools
 import re
 import shlex
 import subprocess
@@ -89,6 +90,23 @@ class Device(collections.namedtuple('DeviceBase', 'path opts')):
     def smartctl_select(self):
         return ['--device', self.type, self.path]
 
+    @staticmethod
+    def from_string(string):
+        parser = argparse.ArgumentParser()
+        parser.add_argument('-d', '--device', dest='type')
+
+        tokens = shlex.split(string, comments=True)
+        if not tokens:
+            return None
+
+        return Device(tokens[0], parser.parse_known_args(tokens[1:])[0])
+
+    def __hash__(self):
+        return hash((self.path, self.type))
+
+    def __eq__(self, other):
+        return ((self.path, self.type) == (other.path, other.type))
+
 
 def metric_key(metric, prefix=''):
     return '{prefix}{metric.name}'.format(prefix=prefix, metric=metric)
@@ -128,33 +146,38 @@ def smart_ctl(*args, check=True):
     except subprocess.CalledProcessError as e:
         return e.output.decode('utf-8')
 
+
 def smart_ctl_version():
     return smart_ctl('-V').split('\n')[0].split()[1]
 
 
-def find_devices():
-    """Find SMART devices.
+def scan_devices():
+    """Find SMART devices by scanning.
 
     Yields:
-        (Device) Single device found by smartctl.
+        (Device) Single device found by smartctl --scan-open
     """
-    parser = argparse.ArgumentParser()
-    parser.add_argument('-d', '--device', dest='type')
 
     devices = smart_ctl('--scan-open')
     devices_nvme = smart_ctl('--scan-open', '-d', 'nvme')
 
-    for device in devices.split('\n') + \
+    for line in devices.split('\n') + \
             devices_nvme.split('\n'):
-        device = device.strip()
-        if not device:
-            continue
+        device = Device.from_string(line.strip())
+        if device:
+            yield device
 
-        tokens = shlex.split(device, comments=True)
-        if not tokens:
-            continue
 
-        yield Device(tokens[0], parser.parse_args(tokens[1:]))
+def smartd_devices(config='/etc/smartd.conf'):
+    """Find SMART devices by reading smartd configuration.
+
+    Yields:
+        (Device) Single device configured
+    """
+    with open(config) as f:
+        for line in f:
+            if line.startswith('/dev/'):
+                yield Device.from_string(line.strip())
 
 
 def device_is_active(device):
@@ -322,7 +345,12 @@ def collect_ata_error_count(device):
 def collect_disks_smart_metrics():
     now = int(datetime.datetime.utcnow().timestamp())
 
-    for device in find_devices():
+    devices = set()
+    for device in itertools.chain(scan_devices(), smartd_devices()):
+        if device in devices:
+            continue
+        devices.add(device)
+
         yield Metric('smartctl_run', device.base_labels, now)
 
         is_active = device_is_active(device)