make nagios_performance default to true;

be more careful handling the input value;
allow Check instances to report configuration errors
(#12)

README.rst

@@ -201,6 +201,9 @@ To do
 Changes
 *******
 
+- Parse metrics from Nagios plugin output by default.  If thresholds are
+  specified and metric parsing is disabled, an error is generated.
+
 0.5.3 (2015-03-10)
 ==================
 

src/zc/cimaa/agent.py

@@ -64,13 +64,22 @@ def __init__(self, config):
                     try:
                         cparser = zc.cimaa.parser.parse_file(path)
                     except zc.cimaa.parser.Error:
-                        checks.append(BadCheck(prefix, path))
+                        checks.append(BadCheck(prefix, path,
+                                               'error parsing %s' % path))
                     else:
                         for section in cparser:
                             config = dict(cparser[section])
-                            if not section.startswith('//'):
-                                section = prefix + section
-                            checks.append(Check(section, config))
+                            if section.startswith('//'):
+                                fullname = section
+                            else:
+                                fullname = prefix + section
+                            try:
+                                checks.append(Check(fullname, config))
+                            except zc.cimaa.parser.Error as e:
+                                checks.append(BadCheck(
+                                    prefix, section,
+                                    'error loading check %s [%s]: %s'
+                                    % (path, section, e)))
 
             signal.signal(signal.SIGTERM, self.shutdown)
 
@@ -224,8 +233,22 @@ def __init__(self, name, config):
         if 'thresholds' in config:
             self.thresholds = zc.cimaa.threshold.Thresholds(
                 config['thresholds'])
-        self.parse_nagios = (
-            config.get('nagios_performance', '').lower() == 'true')
+        parse = True
+        if 'nagios_performance' in config:
+            parse = config['nagios_performance'].lower()
+            if parse == 'true':
+                pass
+            elif parse == 'false':
+                if 'thresholds' in config:
+                    raise zc.cimaa.parser.Error(
+                        'nagios_performance can\'t be false'
+                        ' when thresholds are specified')
+                parse = False
+            else:
+                raise zc.cimaa.parser.Error(
+                    'bad value for nagios_performance: %r'
+                    % config['nagios_performance'])
+        self.parse_nagios = parse
 
     def should_run(self, minute):
         interval = self.interval
@@ -391,17 +414,18 @@ class BadCheck(Check):
     retry = 0
     chances = 1
 
-    def __init__(self, name, path):
+    def __init__(self, name, path, message):
         self.name = name
         self.path = path
+        self.message = message
 
     def should_run(self, minute):
         return True
 
     def perform(self):
         return dict(faults=[
             dict(
-                message="error parsing %s" % self.path,
+                message=self.message,
                 severity=logging.CRITICAL,
                 updated=time.time(),
                 ),

src/zc/cimaa/metrics.rst

@@ -151,26 +151,24 @@ Nagios plugins can include performance data in their output::
    >>> with open('foo.txt', 'w') as f:
    ...     f.write(src)
 
-Normally, performance data is ignored:
+Performance data is parsed by default:
 
     >>> agent.perform(0)
+    2014-12-13T16:14:47.820000 //test.example.com/test/foo.txt#/ 2643.0 MB
+    2014-12-13T16:14:47.820000 //test.example.com/test/foo.txt#/boot 68.0 MB
+    2014-12-13T16:14:47.820000 //test.example.com/test/foo.txt#/home 69357.0 MB
+    2014-12-13T16:14:47.820000 //test.example.com/test/foo.txt#/var/log 818.0 MB
+    2014-12-13T16:14:47.820000 //test.example.com/test/foo.txt#speed 0.0 
+    2014-12-13T16:14:47.820000 //test.example.com/test/foo.txt#loudness 0.0 
+
     >>> print agent.db
-    {'test.example.com': [{'message': 'Missing metric (2 of 4)',
-                           'name': '//test.example.com/test/foo.txt#speed',
-                           'severity': 40,
-                           'since': 1418487287.82,
-                           'updated': 1418487287.82},
-                          {'message': 'Missing metric (2 of 4)',
-                           'name': '//test.example.com/test/foo.txt#loudness',
-                           'severity': 40,
-                           'since': 1418487287.82,
-                           'updated': 1418487287.82}]}
+    {'test.example.com': []}
 
     >>> agent.clear()
 
-If we want parsing of performance data, we need to use the
-``nagios_performance`` option in the check definition:
-::
+The configuration setting ``nagios_performance`` controls whether
+metrics are parsed from Nagios-style output, and can be specified
+explicitly::
 
   [foo.txt]
   command = PY filecheck.py foo.txt
@@ -200,6 +198,81 @@ If we want parsing of performance data, we need to use the
 
     >>> agent.clear()
 
+If thresholds are specified and ``nagios_performance`` is set to false,
+a fault is generated when the configuration is loaded::
+
+  [foo.txt]
+  command = PY filecheck.py foo.txt
+  nagios_performance = FALSE
+  thresholds =
+    speed warning > 50 error > 70 critical > 110 clear < 60
+    loudness warning > 11 error > 20
+    free ? warning <= 20 error <= 10 critical <= 3
+
+.. -> src
+
+    >>> with open(os.path.join('agent.d', 'test.cfg'), 'w') as f:
+    ...     f.write(src.replace('PY', sys.executable))
+    >>> agent = zc.cimaa.agent.Agent('agent.cfg')
+    >>> agent.perform(0)
+    OutputAlerter trigger //test.example.com/test/
+      error loading check agent.d/test.cfg [foo.txt]:
+      nagios_performance can't be false when thresholds are specified
+    >>> print agent.db
+    {'test.example.com':
+     [{'message': "error loading check agent.d/test.cfg [foo.txt]:
+          nagios_performance can't be false when thresholds are specified",
+       'name': '//test.example.com/test/',
+       'severity': 50,
+       'since': 1418487287.82,
+       'triggered': 'y',
+       'updated': 1418487287.82}]}
+
+Without thresholds, disable metrics parsing is allowed, and can be used
+to avoid problems with output from some Nagios-style plugins::
+
+  [foo.txt]
+  command = PY filecheck.py foo.txt
+  nagios_performance = FALSE
+
+.. -> src
+
+    >>> with open(os.path.join('agent.d', 'test.cfg'), 'w') as f:
+    ...     f.write(src.replace('PY', sys.executable))
+    >>> agent = zc.cimaa.agent.Agent('agent.cfg')
+
+    >>> agent.perform(0)
+    >>> print agent.db
+    {'test.example.com': []}
+
+    >>> agent.clear()
+
+Specifying an insane value for ``nagios_performance`` will also generate
+a fault::
+
+  [foo.txt]
+  command = PY filecheck.py foo.txt
+  nagios_performance = yada yada
+
+.. -> src
+
+    >>> with open(os.path.join('agent.d', 'test.cfg'), 'w') as f:
+    ...     f.write(src.replace('PY', sys.executable))
+    >>> agent = zc.cimaa.agent.Agent('agent.cfg')
+    >>> agent.perform(0)
+    OutputAlerter trigger //test.example.com/test/
+      error loading check agent.d/test.cfg [foo.txt]:
+      bad value for nagios_performance: 'yada yada'
+    >>> print agent.db
+    {'test.example.com':
+     [{'message': "error loading check agent.d/test.cfg [foo.txt]:
+          bad value for nagios_performance: 'yada yada'",
+       'name': '//test.example.com/test/',
+       'severity': 50,
+       'since': 1418487287.82,
+       'triggered': 'y',
+       'updated': 1418487287.82}]}
+
 Logging metrics handler
 ========================