New metric namespace implemented and working fine.

main.py

@@ -4,33 +4,26 @@
 
 app = Flask('zfs_exporter')
 
-import arcstats
-import abdstats
-import zfetchstats
-import dnodestats
-import dbufstats
-import dmu_tx
-import xuiostats
-import zilstats
-import vdevstats
-import pools
+from zfx_collectors import StatsCollector, PoolstatsCollector
 
 REGISTRY.unregister(PROCESS_COLLECTOR)
 REGISTRY.unregister(PLATFORM_COLLECTOR)
-REGISTRY.register(arcstats.ArcstatsCollector())
-REGISTRY.register(abdstats.AbdstatsCollector())
-REGISTRY.register(zfetchstats.ZfetchstatsCollector())
-REGISTRY.register(dnodestats.DnodestatsCollector())
-REGISTRY.register(dbufstats.DbufstatsCollector())
-REGISTRY.register(dmu_tx.DmutxCollector())
-REGISTRY.register(xuiostats.XuiostatsCollector())
-REGISTRY.register(zilstats.ZilstatsCollector())
-REGISTRY.register(vdevstats.VdevstatsCollector())
-REGISTRY.register(pools.PoolstatsCollector())
+REGISTRY.register(StatsCollector('/proc/spl/kstat/zfs/arcstats',		'zfs_arc_',		'ARC statistics'))
+REGISTRY.register(StatsCollector('/proc/spl/kstat/zfs/abdstats',		'zfs_abd_',		'ABD statistics'))
+REGISTRY.register(StatsCollector('/proc/spl/kstat/zfs/dbufstats',		'zfs_dbuf_',		'DBUF statistics'))
+REGISTRY.register(StatsCollector('/proc/spl/kstat/zfs/dnodestats',		'zfs_',			'DNode statistics'))
+REGISTRY.register(StatsCollector('/proc/spl/kstat/zfs/dmu_tx',  		'zfs_',			'DMU TX statistics'))
+REGISTRY.register(StatsCollector('/proc/spl/kstat/zfs/vdev_cache_stats',	'zfs_vdev_cache_',	'VDev cache statistics'))
+REGISTRY.register(StatsCollector('/proc/spl/kstat/zfs/vdev_mirror_stats',	'zfs_vdev_mirror_',	'VDev mirror statistics'))
+REGISTRY.register(StatsCollector('/proc/spl/kstat/zfs/xuio_stats',		'zfs_xuio_',		'XUIO statistics'))
+REGISTRY.register(StatsCollector('/proc/spl/kstat/zfs/zfetchstats',		'zfs_zfetch_',		'ZFetch statistics'))
+REGISTRY.register(StatsCollector('/proc/spl/kstat/zfs/zil',			'zfs_',		     	'ZIL statistics'))
+REGISTRY.register(PoolstatsCollector())
+
 
 @app.route('/')
 def status():
-	return Response('PID: {}\n'.format(os.getpid()))
+	return Response('ZFS Exporter is running (PID: {})\n'.format(os.getpid()))
 
 
 @app.route('/metrics')

zfx_collectors.py

@@ -0,0 +1,108 @@
+import os
+import re
+from prometheus_client.core import GaugeMetricFamily
+
+class StatsCollector(object):
+	"""
+	Generic ZFS statistic collector.
+	"""
+	def __init__(self, path, m_pfx, m_desc):
+		"""
+		Initialized the collector object.
+	
+		Parameters
+		----------
+		path : str
+			The full path to the metric file.
+		m_pfx : str
+			Prefix for the names of generated metrics.
+		m_desc : str
+			Metric description string that will be set for every metric from the file.
+		"""
+		self.path   = path
+		self.m_pfx  = m_pfx
+		self.m_desc = m_desc
+
+
+	def collect(self):
+		"""
+		Collects metrics from the stats file. The expected syntax of the lines 
+		with metric data has 3 columns, ie.:
+	
+		hits				4    168948958
+		misses				4    4767869
+		...
+	
+		Returns
+		-------
+		Yields metrics of the Gauge type.
+		"""
+		try:
+			with open(self.path, 'r') as f:
+				mline = re.compile('^[_a-z]+ +[0-9] +[0-9]+$')
+				for l in f:
+					if not mline.match(l):
+						continue
+					items = re.split(r' +', l)
+					if len(items) != 3 and type(items[1]) == int:
+						continue
+					yield GaugeMetricFamily(self.m_pfx + items[0], self.m_desc, value=float(items[2]))
+		except Exception as e:
+			print('Error: {}'.format(str(e)))
+
+
+class PoolstatsCollector(object):
+	"""
+	Per pool statistic collector.
+	"""
+	def __init__(self):
+		self.states = { # valid pool states
+				'ONLINE':	1.0,
+				'DEGRADED':	0.2,
+				'FAULTED':	0.1,
+				'OFFLINE':	0.0,
+				'UNAVAIL':	-1.0,
+				'REMOVED':	-2.0
+				}
+
+
+	def get_state_num(self, state):
+		"""
+		Translates the state string into the corresponding float number
+		or returns -3.0 if not found.
+		"""
+		return self.states[state] if state in self.states.keys() else -3.0 # UNKNOWN
+
+
+	def collect(self):
+		"""
+		Discovers the pools by searching for folders in /proc/spl/kstat/zfs, 
+		then extracts the state and IO stats from the files.
+
+		Returns
+		-------
+		Yields metrics of the Gauge type.
+		"""
+		# Metric declarations	
+		# Find the ZFS pools
+		for pooldir in  [f.path for f in os.scandir('/proc/spl/kstat/zfs') if f.is_dir()]:
+			poolname = pooldir.split('/')[-1]
+			# Load state from file
+			try:
+				with open(pooldir + '/state', 'r') as f:
+					for l in f:
+						STATE = GaugeMetricFamily('zfs_pool_state', 'Pool state (ONLINE = 1, OFFLINE = 0)', labels=['pool'])
+						STATE.add_metric([poolname], self.get_state_num(l.strip()))
+						yield STATE
+			except Exception as e:
+				print('Error: {}'.format(str(e)))
+			# Load IO stats from file
+			iostats_p = pooldir + '/io'
+			lines = open(iostats_p, 'r').readlines() if os.path.isfile(iostats_p) else []
+			if len(lines) > 2:
+				keys = re.split(r' +', lines[1].strip())
+				vals = re.split(r' +', lines[2].strip())
+				for (key, value) in zip(keys, vals):
+					IOSTATS = GaugeMetricFamily('zfs_pool_io_' + key, 'Pool IO statistics', labels=['pool'])
+					IOSTATS.add_metric([poolname], value)
+					yield IOSTATS