A sample spec complex scaling policy

We are supporting complex scaling policies that allow users to specify
conditions for each policy. I'm not sure if we should make this a
generic case for all.

Change-Id: Iac851844a1fe23a654241031b93d05552bbfce13

examples/policies/scaling_policy_complex.spec

@@ -0,0 +1,57 @@
+# Sample scaling policy that can be attached to a cluster
+
+constraints:
+  # Min number of nodes to keep the cluster operational
+  min_size: 1
+
+  # Max number of nodes to cap resource consumption
+  max_size: 10
+
+policies:
+  - condition:
+      # name of meter for testing
+      meter: cpu_util
+      # comparison operator, valid values include 'lt', 'gt', 'eq'
+      op: gt
+      # Threshold for testing
+      threshold: 50
+      # Length of each evaluation period in seconds
+      period: 60
+      # Number of evaluations to perform
+      evaluations: 1
+    adjustment:
+      # Adjustment type, valid values include:
+      # EXACT_CAPACITY, CHANGE_IN_CAPACITY, CHANGE_IN_PERCENTAGE
+      type: CHANGE_IN_CAPACITY
+
+      # A number that will be interpreted based on the type setting
+      number: 1
+
+      # When type is set CHNAGE_IN_PERCENTAGE, min_step specifies
+      # that the cluster size will be changed by at least the number
+      # of nodes specified here
+      min_step: 1
+
+  - condition:
+      # name of meter for testing
+      meter: cpu_util
+      # comparison operator, valid values include 'lt', 'gt', 'eq'
+      op: lt
+      # Threshold for testing
+      threshold: 15
+      # Length of each evaluation period in seconds
+      period: 60
+      # Number of evaluations to perform
+      evaluations: 1
+    adjustment:
+       # Adjustment type, valid values include:
+      # EXACT_CAPACITY, CHANGE_IN_CAPACITY, CHANGE_IN_PERCENTAGE
+      type: CHANGE_IN_CAPACITY
+
+      # A number that will be interpreted based on the type setting
+      number: 1
+
+      # When type is set CHNAGE_IN_PERCENTAGE, min_step specifies
+      # that the cluster size will be changed by at least the number
+      # of nodes specified here
+      min_step: 1