Send flavor resources as value metadata

This addresses an issue where the resources dimension could
contain a string with prohibited characters, for example:

"VCPU:64, MEMORY_MB:393216, DISK_GB:110, None".

This change moves the flavor resource string to the value_meta
field which has fewer restrictions over the content. If we
later want to index resources as a function of the flavor
resource fields, for example CPU count, we could add those
as separate dimensions on the metric.

Author: dougszumski

os_capacity/commands/commands.py

@@ -59,13 +59,16 @@ def take_action(self, parsed_args):
             free = group[3]
             metrics_to_send.append(metrics.Metric(
                 name="resources.total", value=total,
-                dimensions={"flavor": flavors, "resources": resources}))
+                value_meta={"flavor_resources": resources},
+                dimensions={"flavor": flavors}))
             metrics_to_send.append(metrics.Metric(
                 name="resources.used", value=used,
-                dimensions={"flavor": flavors, "resources": resources}))
+                value_meta={"flavor_resources": resources},
+                dimensions={"flavor": flavors}))
             metrics_to_send.append(metrics.Metric(
                 name="resources.free", value=free,
-                dimensions={"flavor": flavors, "resources": resources}))
+                value_meta={"flavor_resources": resources},
+                dimensions={"flavor": flavors}))
         metrics.send_metrics(self.app.monitoring_client, metrics_to_send)
 
         return (

os_capacity/data/metrics.py

@@ -17,7 +17,7 @@
 import time
 
 Metric = collections.namedtuple(
-    "Metric", ("name", "value", "dimensions"))
+    "Metric", ("name", "value", "value_meta", "dimensions"))
 
 SEND_METRICS = 'OS_CAPACITY_SEND_METRICS' in os.environ
 
@@ -33,7 +33,7 @@ def send_metrics(monitoring_client, metrics):
             "name": "os_capacity.%s" % metric.name,
             "value": float(metric.value),
             "timestamp": timestamp,
-            "value_meta": None,
+            "value_meta": metric.value_meta,
             "dimensions": metric.dimensions,
         })
     response = monitoring_client.post("/metrics", json=formatted_metrics)