Merge pull request #133 from hongchaodeng/scope_health

ApplicationScope: add `health` core scope

Author: Mikkel Mork Hegnhoj

4.application_scopes.md

@@ -133,32 +133,52 @@ The health scope on its own does not take any action based on health status. It
  - Application upgrade traits can monitor the aggregate health of a health scope and decide when to initiate an automatic rollback.
  - Monitoring applications can monitor the aggregate health of a health scope to issue alerts.
 
-#### Example
-This is an example of a health scope definition. 
+The health scope is defined by the following spec:
+
 ```yaml
 apiVersion: core.hydra.io/v1alpha1
 kind: ApplicationScope
 metadata:
-  name: myHealthScope
+  name: health
   annotations:
     version: v1.0.0
-    description: "The production configuration for Corp CMS"
+    description: "aggregated health state for a group of components."
 spec:
-  type: core.hydra.io/v1.HealthScope
+  type: core.hydra.io/v1alpha1.HealthScope
   allowComponentOverlap: true
   parameters:
-    - name: healthThresholdPercentage     
-      description: The % of healthy components required to upgrade scope
-      type: double
-      required: Y
-    - name: logAnalyticsQueryId
-      description: an Id for querying log data from your log system
+    - name: probe-method
+      description: The method to probe the components, e.g. 'httpGet'.
       type: string
-      required: false
-    - name: logAnalyticsQueryKey
-      description: a key for querying log data from your log system
+      required: true
+    - name: probe-endpoint
+      description: The endpoint to probe from the components, e.g. '/v1/health'.
       type: string
+      required: true
+    - name: probe-timeout
+      description: The amount of time in seconds to wait when receiving a response before marked failure.
+      type: integer
       required: false
+    - name: probe-interval
+      description: The amount of time in seconds between probing tries.
+      type: integer
+      required: false
+    - name: failure-rate-threshold
+      description: If the rate of failure of total probe results is above this threshold, declared 'failed'.
+      type: double
+      required: false
+    - name: healthy-rate-threshold
+      description: If the rate of healthy of total probe results is above this threshold, declared 'healthy'.
+      type: double
+      required: false
+    - name: healthThresholdPercentage
+      description: The % of healthy components required to upgrade scope
+      type: double
+      required: N
+    - name: requiredHealthyComponents
+      description: Comma-separated list of names of the components required to be healthy for the scope to be health.
+      type: string
+      required: N
 ```
 
 ## Extended application scope type definitions