Apply code review comments, update docs.

Author: brian-brazil

AUTHORS.md

@@ -5,4 +5,5 @@ Maintainers of this repository:
 The following individuals have contributed code to this repository
 (listed in alphabetical order):
 
+* Andrea Fagan <[email protected]>
 * Brian Brazil <[email protected]>

README.md

@@ -133,6 +133,12 @@ c.labels('get', '/').inc()
 c.labels('post', '/submit').inc()
 ```
 
+### Process Collector
+
+The Python Client automatically exports metrics about process CPU usage, RAM,
+file descriptors and start time. These all have the prefix `process\_`, and
+are only currently available on Linux.
+
 ## Exporting
 
 There are several options for exporting metrics.
@@ -180,4 +186,5 @@ g.set(1)
 write_to_textfile('/configured/textfile/path/raid.prom', registry)
 ```
 
-A separate registry is used, as the default registry may contain other metrics.
+A separate registry is used, as the default registry may contain other metrics
+such as those from the Process Collector.

prometheus_client/__init__.py

@@ -447,7 +447,6 @@ def write_to_textfile(path, registry):
     os.rename(tmppath, path)
 
 
-
 class ProcessCollector(object):
     """Collector for Standard Exports such as cpu and memory."""
     def __init__(self, namespace='', pid='self', proc='/proc', registry=REGISTRY):
@@ -465,9 +464,12 @@ def __init__(self, namespace='', pid='self', proc='/proc', registry=REGISTRY):
         except (ValueError, TypeError):
             pass
 
-        self._can_read_proc = os.access(os.path.join(self._proc, 'stat'), os.R_OK)
-        if self._can_read_proc:
+        # This is used to test if we can access /proc.
+        self._btime = 0
+        try:
             self._btime = self._boot_time()
+        except IOError:
+            pass
         if registry:
           registry.register(self)
 
@@ -478,7 +480,7 @@ def _boot_time(self):
                     return float(line.split()[1])
 
     def collect(self):
-        if not self._can_read_proc:
+        if not self._btime:
             return []
 
         result = []
@@ -491,15 +493,15 @@ def collect(self):
             rss.add_sample(self._prefix + 'resident_memory_bytes', {}, float(parts[21]) * self._pagesize)
             start_time = Metric(self._prefix + 'start_time_seconds',
                                 'Start time of the process since unix epoch in seconds.', 'gauge')
-            start_time_secs = float(parts[18]) / self._ticks
+            start_time_secs = float(parts[19]) / self._ticks
             start_time.add_sample(self._prefix + 'start_time_seconds',{} , start_time_secs + self._btime)
             utime = float(parts[11]) / self._ticks
             stime = float(parts[12]) / self._ticks
             cpu = Metric(self._prefix + 'cpu_seconds_total',
                          'Total user and system CPU time spent in seconds.', 'counter')
             cpu.add_sample(self._prefix + 'cpu_seconds_total', {}, utime + stime)
             result.extend([vmem, rss, start_time, cpu])
-        except (IOError):
+        except IOError:
             pass
 
         try:
@@ -510,19 +512,18 @@ def collect(self):
                         max_fds.add_sample(self._prefix + 'max_fds', {}, float(line.split()[3]))
                         break
             open_fds = Metric(self._prefix + 'open_fds', 'Number of open file descriptors.', 'gauge')
-            open_fds.add_sample(self._prefix + 'open_fds', {}, os.listdir(os.path.join(self._pid, 'fd')))
+            open_fds.add_sample(self._prefix + 'open_fds', {}, len(os.listdir(os.path.join(self._pid, 'fd'))))
             result.extend([open_fds, max_fds])
         except IOError:
             pass
 
         return result
 
 
-PROCESS_COLLECTOR = ProcessCollector(proc='.')
+PROCESS_COLLECTOR = ProcessCollector()
 """Default ProcessCollector in default Registry REGISTRY."""
 
 
-
 if __name__ == '__main__':
     c = Counter('cc', 'A counter')
     c.inc()

tests/proc/26231/limits

@@ -13,4 +13,3 @@ Max file locks            unlimited            unlimited            locks
 Max pending signals       62898                62898                signals
 Max msgqueue size         819200               819200               bytes
 Max nice priority         0                    0
-Max rMax rMax rMax rMax rMax rMax rMax rMax rMax rMax rMax rMax rMax rMax rMax mited            unlimited            us

tests/proc/584/stat

@@ -1,2 +1 @@
 1020 ((a b ) ( c d) ) R 28378 1020 28378 34842 1020 4218880 286 0 0 0 0 0 0 0 20 0 1 0 10839175 10395648 155 18446744073709551615 4194304 4238788 140736466511168 140736466511168 140609271124624 0 0 0 0 0 0 0 17 5 0 0 0 0 0 6336016 6337300 25579520 140736466515030 140736466515061 140736466515061 140736466518002 0
-#!/bin/cat /proc/self/stat

tests/test_client.py

@@ -280,23 +280,36 @@ def test_working(self):
 
         self.assertEqual(17.21, self.registry.get_sample_value('process_cpu_seconds_total'))
         self.assertEqual(56274944.0, self.registry.get_sample_value('process_virtual_memory_bytes'))
-        self.assertEqual((1981.0*collector._pagesize), self.registry.get_sample_value('process_resident_memory_bytes'))
-        self.assertEqual((0.0/collector._ticks+1418183276), self.registry.get_sample_value('process_start_time_seconds'))
+        self.assertEqual(8114176, self.registry.get_sample_value('process_resident_memory_bytes'))
+        self.assertEqual(1418184099.75, self.registry.get_sample_value('process_start_time_seconds'))
         self.assertEqual(2048.0, self.registry.get_sample_value('process_max_fds'))
-        self.assertEqual(5.0, len(self.registry.get_sample_value('process_open_fds')))
+        self.assertEqual(5.0, self.registry.get_sample_value('process_open_fds'))
         self.assertEqual(None, self.registry.get_sample_value('process_fake_namespace'))
 
+    def test_namespace(self):
+        collector = ProcessCollector(proc=self.test_proc, pid=26231, registry=self.registry, namespace='n')
+        collector._pagesize = 4096
+        collector._ticks = 100
+
+        self.assertEqual(17.21, self.registry.get_sample_value('n_process_cpu_seconds_total'))
+        self.assertEqual(56274944.0, self.registry.get_sample_value('n_process_virtual_memory_bytes'))
+        self.assertEqual(8114176, self.registry.get_sample_value('n_process_resident_memory_bytes'))
+        self.assertEqual(1418184099.75, self.registry.get_sample_value('n_process_start_time_seconds'))
+        self.assertEqual(2048.0, self.registry.get_sample_value('n_process_max_fds'))
+        self.assertEqual(5.0, self.registry.get_sample_value('n_process_open_fds'))
+        self.assertEqual(None, self.registry.get_sample_value('process_cpu_seconds_total'))
+
     def test_working_584(self):
         collector = ProcessCollector(proc=self.test_proc, pid=584, registry=self.registry)
         collector._pagesize = 4096
         collector._ticks = 100
 
         self.assertEqual(0.0, self.registry.get_sample_value('process_cpu_seconds_total'))
         self.assertEqual(10395648.0, self.registry.get_sample_value('process_virtual_memory_bytes'))
-        self.assertEqual((155.0*collector._pagesize), self.registry.get_sample_value('process_resident_memory_bytes'))
-        self.assertEqual((0.0/collector._ticks+1418183276), self.registry.get_sample_value('process_start_time_seconds'))
+        self.assertEqual(634880, self.registry.get_sample_value('process_resident_memory_bytes'))
+        self.assertEqual(1418291667.75, self.registry.get_sample_value('process_start_time_seconds'))
         self.assertEqual(None, self.registry.get_sample_value('process_max_fds'))
-        self.assertEqual(None, (self.registry.get_sample_value('process_open_fds')))
+        self.assertEqual(None, self.registry.get_sample_value('process_open_fds'))
 
     def test_working_fake_pid(self):
         collector = ProcessCollector(proc=self.test_proc, pid=123, registry=self.registry)