Check for local crash dumps

Add a check that monitors crash dumps. The specified crash directory
is scanned for sub-directories named 'YYYYmmddHHMM' which contain the
dump files. The 'dump_count' metric is the number of sub-directories
(i.e., the number of crash dumps present) and the 'value_meta' dict
contains the date-/timestamp of the most recent crash.

Implements: blueprint check-for-crashes

Change-Id: I20b584c68644ff2e76baabab78e965e682759aa0

conf.d/crash.yaml.example

@@ -0,0 +1,6 @@
+init_config:
+    # crash_dir: /var/crash
+
+instances:
+    # Crash check only supports one configured instance
+    - name: crash_stats

monasca_agent/collector/checks_d/crash.py

@@ -0,0 +1,46 @@
+import logging
+import os
+
+from datetime import datetime
+
+import monasca_agent.collector.checks as checks
+
+log = logging.getLogger(__name__)
+
+
+class Crash(checks.AgentCheck):
+
+    def __init__(self, name, init_config, agent_config):
+        super(Crash, self).__init__(name, init_config, agent_config)
+        self.crash_dir = self.init_config.get('crash_dir', '/var/crash')
+        log.debug('crash dir: %s', self.crash_dir)
+
+    def check(self, instance):
+        """
+        Capture crash dump statistics
+        """
+        dimensions = self._set_dimensions(None, instance)
+        dump_count = 0
+        value_meta = {'latest': ''}
+
+        # Parse the crash directory
+        if os.path.isdir(self.crash_dir):
+            for entry in sorted(os.listdir(self.crash_dir), reverse=True):
+                if os.path.isdir(os.path.join(self.crash_dir, entry)):
+                    try:
+                        dt = datetime.strptime(entry, '%Y%m%d%H%M')
+                    except ValueError:
+                        continue
+
+                    # Found a valid crash dump directory
+                    log.debug('found crash dump dir: %s',
+                              os.path.join(self.crash_dir, entry))
+                    dump_count += 1
+
+                    # Return the date-/timestamp of the most recent crash
+                    if dump_count == 1:
+                        value_meta = {'latest': unicode(dt)}
+
+        log.debug('dump_count: %s', dump_count)
+        self.gauge('crash.dump_count', dump_count, dimensions=dimensions,
+                   value_meta=value_meta)

tests/test_crash.py

@@ -0,0 +1,55 @@
+import os
+import shutil
+import unittest
+import uuid
+
+from common import get_check
+
+
+class TestCrash(unittest.TestCase):
+
+    def setUp(self):
+        self.crash_dir = '/tmp/crash-test-%s' % str(uuid.uuid4())
+        os.mkdir(self.crash_dir)
+
+    def tearDown(self):
+        shutil.rmtree(self.crash_dir)
+
+    def test_checks(self):
+        config = """
+init_config:
+   crash_dir: %s
+
+instances:
+   - name: crash_stats
+""" % self.crash_dir
+
+        (check, instances) = get_check('crash', config)
+
+        # Baseline check
+        check.check(instances[0])
+        metrics = check.get_metrics()
+        self.assertEqual(metrics[0].value, 0)
+        self.assertEqual(metrics[0].value_meta['latest'], '')
+
+        # Add a crash and re-check
+        os.mkdir(os.path.join(self.crash_dir,'201504141011'))
+
+        check.check(instances[0])
+        metrics = check.get_metrics()
+        self.assertEqual(metrics[0].value, 1)
+        self.assertEqual(metrics[0].value_meta['latest'],
+                         '2015-04-14 10:11:00')
+
+        # Add a second crash and re-check
+        os.mkdir(os.path.join(self.crash_dir,'201505222303'))
+
+        check.check(instances[0])
+        metrics = check.get_metrics()
+        self.assertEqual(metrics[0].value, 2)
+        self.assertEqual(metrics[0].value_meta['latest'],
+                         '2015-05-22 23:03:00')
+
+
+if __name__ == "__main__":
+    unittest.main()