Add MAP mutator

This mutator can map arbitrary values to new values. This is useful with
metrics reporting resource status as their value, but multiple statuses
are billable.

Change-Id: I8fcb9f2aa4ef23432089bfd6351a9c03ce3cf941

cloudkitty/collector/__init__.py

@@ -93,7 +93,9 @@ METRIC_BASE_SCHEMA = {
     # (NONE, NUMBOOL, NOTNUMBOOL, FLOOR, CEIL).
     # Defaults to NONE
     Required('mutate', default='NONE'):
-        In(['NONE', 'NUMBOOL', 'NOTNUMBOOL', 'FLOOR', 'CEIL']),
+        In(['NONE', 'NUMBOOL', 'NOTNUMBOOL', 'FLOOR', 'CEIL', 'MAP']),
+    # Map dict used if mutate == 'MAP'
+    Optional('mutate_map'): dict,
     # Collector-specific args. Should be overriden by schema provided for
     # the given collector
     Optional('extra_args'): dict,
@@ -270,6 +272,22 @@ def check_duplicates(metric_name, metric):
     return metric
 
 
+def validate_map_mutator(metric_name, metric):
+    """Validates MAP mutator"""
+    mutate = metric.get('mutate')
+    mutate_map = metric.get('mutate_map')
+
+    if mutate == 'MAP' and mutate_map is None:
+        raise InvalidConfiguration(
+            'Metric {} uses MAP mutator but mutate_map is missing: {}'.format(
+                metric_name, metric))
+
+    if mutate != 'MAP' and mutate_map is not None:
+        raise InvalidConfiguration(
+            'Metric {} not using MAP mutator but mutate_map is present: '
+            '{}'.format(metric_name, metric))
+
+
 def validate_conf(conf):
     """Validates the provided configuration."""
     collector = get_collector_without_invoke()
@@ -278,4 +296,5 @@ def validate_conf(conf):
         if 'alt_name' not in metric.keys():
             metric['alt_name'] = metric_name
         check_duplicates(metric_name, metric)
+        validate_map_mutator(metric_name, metric)
     return output

cloudkitty/collector/gnocchi.py

@@ -434,7 +434,9 @@ class GnocchiCollector(collector.BaseCollector):
         qty = data['measures']['measures']['aggregated'][0][2]
         converted_qty = ck_utils.convert_unit(
             qty, metconf['factor'], metconf['offset'])
-        mutated_qty = ck_utils.mutate(converted_qty, metconf['mutate'])
+        mutate_map = metconf.get('mutate_map')
+        mutated_qty = ck_utils.mutate(converted_qty, metconf['mutate'],
+                                      mutate_map=mutate_map)
         return metadata, groupby, mutated_qty
 
     def fetch_all(self, metric_name, start, end,

cloudkitty/collector/monasca.py

@@ -199,7 +199,9 @@ class MonascaCollector(collector.BaseCollector):
         qty = data['statistics'][0][1]
         converted_qty = ck_utils.convert_unit(
             qty, metconf['factor'], metconf['offset'])
-        mutated_qty = ck_utils.mutate(converted_qty, metconf['mutate'])
+        mutate_map = metconf.get('mutate_map')
+        mutated_qty = ck_utils.mutate(converted_qty, metconf['mutate'],
+                                      mutate_map=mutate_map)
         return metadata, groupby, mutated_qty
 
     def fetch_all(self, metric_name, start, end,

cloudkitty/collector/prometheus.py

@@ -148,7 +148,9 @@ class PrometheusCollector(collector.BaseCollector):
                 self.conf[metric_name]['factor'],
                 self.conf[metric_name]['offset'],
             )
-            qty = ck_utils.mutate(qty, self.conf[metric_name]['mutate'])
+            mutate_map = self.conf[metric_name].get('mutate_map')
+            qty = ck_utils.mutate(qty, self.conf[metric_name]['mutate'],
+                                  mutate_map=mutate_map)
 
         return metadata, groupby, qty
 

cloudkitty/tests/collectors/test_validation.py

@@ -188,3 +188,26 @@ class MetricConfigValidationTest(tests.TestCase):
             self.assertRaises(
                 collector.InvalidConfiguration,
                 collector.check_duplicates, metric_name, metric)
+
+    def test_validate_map_mutator(self):
+        data = copy.deepcopy(self.base_data)
+
+        # Check that validation succeeds when MAP mutator is not used
+        for metric_name, metric in data['metrics'].items():
+            collector.validate_map_mutator(metric_name, metric)
+
+        # Check that validation raises an exception when mutate_map is missing
+        for metric_name, metric in data['metrics'].items():
+            metric['mutate'] = 'MAP'
+            self.assertRaises(
+                collector.InvalidConfiguration,
+                collector.validate_map_mutator, metric_name, metric)
+
+        data = copy.deepcopy(self.base_data)
+        # Check that validation raises an exception when mutate_map is present
+        # but MAP mutator is not used
+        for metric_name, metric in data['metrics'].items():
+            metric['mutate_map'] = {}
+            self.assertRaises(
+                collector.InvalidConfiguration,
+                collector.validate_map_mutator, metric_name, metric)

cloudkitty/utils/__init__.py

@@ -251,8 +251,8 @@ def tempdir(**kwargs):
             LOG.debug('Could not remove tmpdir: %s', e)
 
 
-def mutate(value, mode='NONE'):
-    """Mutate value according provided mode."""
+def mutate(value, mode='NONE', mutate_map=None):
+    """Mutate value according to provided mode."""
 
     if mode == 'NUMBOOL':
         return float(value != 0.0)
@@ -266,6 +266,12 @@ def mutate(value, mode='NONE'):
     if mode == 'CEIL':
         return math.ceil(value)
 
+    if mode == 'MAP':
+        ret = 0.0
+        if mutate_map is not None:
+            ret = mutate_map.get(value, 0.0)
+        return ret
+
     return value
 
 

doc/source/admin/configuration/collector.rst

@@ -177,7 +177,7 @@ Quantity mutation
 ~~~~~~~~~~~~~~~~~
 
 It is also possible to mutate the collected qty with the ``mutate`` option.
-Four values are accepted for this parameter:
+Five values are accepted for this parameter:
 
 * ``NONE``: This is the default. The collected data is not modifed.
 
@@ -190,6 +190,11 @@ Four values are accepted for this parameter:
 * ``NOTNUMBOOL``: If the collected qty equals 0, set it to 1. Else, set it to
   0.
 
+* ``MAP``: Map arbritrary values to new values as defined through the
+  ``mutate_map`` option (dictionary). If the value is not found in
+  ``mutate_map``, set it to 0. If ``mutate_map`` is not defined or is empty,
+  all values are set to 0.
+
 .. warning::
 
    Quantity mutation is done **after** conversion. Example::
@@ -233,6 +238,26 @@ when the instance is in ACTIVE state but 4 if the instance is in ERROR state:
        metadata:
          - flavor_id
 
+The ``MAP`` mutator is useful when multiple statuses should be billabled. For
+example, the following Prometheus metric has a value of 0 when the instance is
+in ACTIVE state, but operators may want to rate other non-zero states:
+
+.. code-block:: yaml
+
+   metrics:
+     openstack_nova_server_status:
+       unit: instance
+       mutate: MAP
+       mutate_map:
+         0.0: 1.0  # ACTIVE
+         11.0: 1.0 # SHUTOFF
+         12.0: 1.0 # SUSPENDED
+         16.0: 1.0 # PAUSED
+       groupby:
+         - id
+       metadata:
+         - flavor_id
+
 Display name
 ~~~~~~~~~~~~
 

releasenotes/notes/map-mutator-632b8629c0482e94.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Adds a ``MAP`` mutator to map arbitrary values to new values. This is
+    useful with metrics reporting resource status as their value, but multiple
+    statuses are billable.