update API for consistency

Author: iamzili

vertical-pod-autoscaler/enhancements/8515-support-custom-request-to-limit-ratio/README.md

@@ -62,17 +62,23 @@ Some examples of the VPA CRD using the new `RequestToLimitRatio` field are provi
 
 A new `RequestToLimitRatio` field will be added, with the following sub-fields:
 
-* `RequestToLimitRatio.CPU.Type` or `RequestToLimitRatio.Memory.Type` (type: `string`, required): Specifies how to apply limits proportionally to the requests. `Type` can have the following values:  
+* [Optional] `RequestToLimitRatio.CPU.Type` or `RequestToLimitRatio.Memory.Type` (type `string`): Specifies how to apply limits proportionally to the requests. `Type` can have the following values:  
   * `Factor` (type: `floating-point number`): Interpreted as a multiplier for the recommended request.  
     * Example: a value of `2` will double the limits.  
   * `Quantity` (type: `string`): Adds an absolute value on top of the requests to determine the new limit.  
-    * Example: for memory, a value of `100Mi` means the new limit will be: calculated memory request + `100Mi`.  
+    * Example: for memory, a value of `100Mi` means the new limit will be: calculated memory request + `100Mi`. 
+  * If `RequestToLimitRatio.CPU.Type` or `RequestToLimitRatio.Memory.Type` is not specified, the default value is `Factor`.
 
-* `RequestToLimitRatio.CPU.Value` (type: `string`, required): Specifies the magnitude of the ratio between request and limit, interpreted according to `RequestToLimitRatio.CPU.Type`:  
-  * If `Type` is `Factor`: a value of `3` will triple the CPU limits.  
-  * If `Type` is `Quantity`: if the value is set to 200m, then the CPU limit will be set to the CPU request plus 200 millicores.
+* [Optional] `RequestToLimitRatio.CPU.Factor` (type `float`): The factor to apply to the CPU request.
+  * If `Type` is `Factor` a value of `3` will triple the CPU limits.  
+  * If `Type` is `Quantity`, this field is not allowed.
 
-* `RequestToLimitRatio.Memory.Value` (type: `string`, required): Similar to `CPU.Value`, except that for `Quantity` the units are memory-based (e.g., `Mi`, `Gi`) rather than CPU millicores (`m`).
+* [Optional] `RequestToLimitRatio.CPU.Quantity` (type `Quantity`): The value specified in this field is added to the request to calculate the new limit.
+  * If `Type` is `Factor`, this field is not allowed.  
+  * If `Type` is `Quantity` a CPU resource quantity added. For example, if the value is `200m`, the CPU limit will be calculated as the CPU request plus 200 millicores.
+
+* [Optional] `RequestToLimitRatio.Memory.Factor` (type `float`): Same as `CPU.Factor`.
+* [Optional] `RequestToLimitRatio.Memory.Quantity` (type `Quantity`): Similar to `CPU.Quantity` except that for `Quantity` the units are memory-based (e.g., `Mi`, `Gi`) rather than CPU millicores (`m`).
 
 ### Behavior
 
@@ -115,7 +121,7 @@ The behavior after implementing this feature is as follows:
 
 * When using the new `RequestToLimitRatio` field, the `controlledValues` field must be set to `RequestsAndLimits`. It does not make sense to specify `RequestToLimitRatio` if VPA is not allowed to update limits. This requirement is enforced by the admission controller.
 * Explicitly prohibit the use of `RequestToLimitRatio` for any resource not listed in `controlledResources`. For example, if the intention is to set a custom ratio for CPU, then the value of the `controlledResources` field must include `cpu`.
-* If `Type` is set to `Quantity`, then its `Value` will be validated using the [ParseQuantity](https://github.com/kubernetes/apimachinery/blob/v0.34.1/pkg/api/resource/quantity.go#L277) function from `apimachinery`.
+* If `Type` is set to `Quantity`, then its value will be validated using the [ParseQuantity](https://github.com/kubernetes/apimachinery/blob/v0.34.1/pkg/api/resource/quantity.go#L277) function from `apimachinery`.
 
 
 ### Feature Enablement and Rollback
@@ -186,11 +192,11 @@ spec:
         controlledValues: RequestsAndLimits
         RequestToLimitRatio:
           cpu:
-            Type: Factor
-            Value: 2
+            type: Factor # this field is optional, if omitted it defaults to "Factor"
+            factor: 2
           memory:
-            Type: Quantity
-            Value: 200Mi
+            type: Quantity
+            quantity: 200Mi
 ```
 
 In the manifest below, we configure VPA to control only the CPU resource's requests and limits for the container named `app`. The CPU limit is calculated by increasing the recommended CPU request by 20% (i.e. `recommended request × 1.2`).
@@ -214,8 +220,8 @@ spec:
         controlledValues: RequestsAndLimits
         RequestToLimitRatio:
           cpu:
-            Type: Factor
-            Value: 1.2
+            type: Factor # this field is optional, if omitted it defaults to "Factor"
+            factor: 1.2
 ```
 
 ## Implementation History