ratelimit: new per descriptor hits-addend support and dynamic hits ad…

…dend (#37567)

Commit Message: api: new per descriptor hits-addend support and dynamic
hits addend
Additional Description:

1. Now, we could get custom hits_addend from the
`envoy.ratelimit.hits_addend`. But if there are multiple rate limit
filters that requrie custom hits_addend, the
`envoy.ratelimit.hits_addend` couldn't meet the requirement.

2. And we cann't also to support different hits_addend for diffferent
descriptots in same request.

This API changes try to meet above two requirements.

Risk Level: low.
Testing: n/a.
Docs Changes: n/a.
Release Notes: n/a.
Platform Specific Features: n/a.

---------

Signed-off-by: wangbaiping(wbpcode) <wangbaiping@bytedance.com>

Mirrored from https://github.com/envoyproxy/envoy @ cac9b87e9c0cd10eafc64817130c27c567395f4d

envoy/config/route/v3/route_components.proto

@@ -1868,6 +1868,7 @@ message VirtualCluster {
 
 // Global rate limiting :ref:`architecture overview <arch_overview_global_rate_limit>`.
 // Also applies to Local rate limiting :ref:`using descriptors <config_http_filters_local_rate_limit_descriptors>`.
+// [#next-free-field: 6]
 message RateLimit {
   option (udpa.annotations.versioning).previous_message_type = "envoy.api.v2.route.RateLimit";
 
@@ -2168,16 +2169,53 @@ message RateLimit {
     }
   }
 
+  message HitsAddend {
+    // Fixed number of hits to add to the rate limit descriptor.
+    //
+    // One of the ``number`` or ``format`` fields should be set but not both.
+    google.protobuf.UInt64Value number = 1 [(validate.rules).uint64 = {lte: 1000000000}];
+
+    // Substitution format string to extract the number of hits to add to the rate limit descriptor.
+    // The same :ref:`format specifier <config_access_log_format>` as used for
+    // :ref:`HTTP access logging <config_access_log>` applies here.
+    //
+    // .. note::
+    //
+    //   The format string must contains only single valid substitution field. If the format string
+    //   not meets the requirement, the configuration will be rejected.
+    //
+    //   The substitution field should generates a non-negative number or string representation of
+    //   a non-negative number. The value of the non-negative number should be less than or equal
+    //   to 1000000000 like the ``number`` field. If the output of the substitution field not meet
+    //   the requirement, this will be treated as an error and the current descriptor will be ignored.
+    //
+    // For example, the ``%BYTES_RECEIVED%`` format string will be replaced with the number of bytes
+    // received in the request.
+    //
+    // One of the ``number`` or ``format`` fields should be set but not both.
+    string format = 2 [(validate.rules).string = {prefix: "%" suffix: "%" ignore_empty: true}];
+  }
+
   // Refers to the stage set in the filter. The rate limit configuration only
   // applies to filters with the same stage number. The default stage number is
   // 0.
   //
   // .. note::
   //
   //   The filter supports a range of 0 - 10 inclusively for stage numbers.
+  //
+  // .. note::
+  //   This is not supported if the rate limit action is configured in the ``typed_per_filter_config`` like
+  //   :ref:`VirtualHost.typed_per_filter_config<envoy_v3_api_field_config.route.v3.VirtualHost.typed_per_filter_config>` or
+  //   :ref:`Route.typed_per_filter_config<envoy_v3_api_field_config.route.v3.Route.typed_per_filter_config>`, etc.
   google.protobuf.UInt32Value stage = 1 [(validate.rules).uint32 = {lte: 10}];
 
   // The key to be set in runtime to disable this rate limit configuration.
+  //
+  // .. note::
+  //   This is not supported if the rate limit action is configured in the ``typed_per_filter_config`` like
+  //   :ref:`VirtualHost.typed_per_filter_config<envoy_v3_api_field_config.route.v3.VirtualHost.typed_per_filter_config>` or
+  //   :ref:`Route.typed_per_filter_config<envoy_v3_api_field_config.route.v3.Route.typed_per_filter_config>`, etc.
   string disable_key = 2;
 
   // A list of actions that are to be applied for this rate limit configuration.
@@ -2192,7 +2230,21 @@ message RateLimit {
   // rate limit configuration. If the override value is invalid or cannot be resolved
   // from metadata, no override is provided. See :ref:`rate limit override
   // <config_http_filters_rate_limit_rate_limit_override>` for more information.
+  //
+  // .. note::
+  //   This is not supported if the rate limit action is configured in the ``typed_per_filter_config`` like
+  //   :ref:`VirtualHost.typed_per_filter_config<envoy_v3_api_field_config.route.v3.VirtualHost.typed_per_filter_config>` or
+  //   :ref:`Route.typed_per_filter_config<envoy_v3_api_field_config.route.v3.Route.typed_per_filter_config>`, etc.
   Override limit = 4;
+
+  // An optional hits addend to be appended to the descriptor produced by this rate limit
+  // configuration.
+  //
+  // .. note::
+  //   This is only supported if the rate limit action is configured in the ``typed_per_filter_config`` like
+  //   :ref:`VirtualHost.typed_per_filter_config<envoy_v3_api_field_config.route.v3.VirtualHost.typed_per_filter_config>` or
+  //   :ref:`Route.typed_per_filter_config<envoy_v3_api_field_config.route.v3.Route.typed_per_filter_config>`, etc.
+  HitsAddend hits_addend = 5;
 }
 
 // .. attention::

envoy/extensions/common/ratelimit/v3/ratelimit.proto

@@ -5,6 +5,8 @@ package envoy.extensions.common.ratelimit.v3;
 import "envoy/type/v3/ratelimit_unit.proto";
 import "envoy/type/v3/token_bucket.proto";
 
+import "google/protobuf/wrappers.proto";
+
 import "udpa/annotations/status.proto";
 import "udpa/annotations/versioning.proto";
 import "validate/validate.proto";
@@ -121,8 +123,20 @@ message RateLimitDescriptor {
 
   // Optional rate limit override to supply to the ratelimit service.
   RateLimitOverride limit = 2;
+
+  // Optional hits_addend for the rate limit descriptor. If set the value will override the
+  // request level hits_addend.
+  // [#not-implemented-hide:]
+  google.protobuf.UInt64Value hits_addend = 3;
 }
 
+// Configuration used to enable local rate limiting.
+//
+// .. note::
+//   The ``LocalRateLimitDescriptor`` is used to configure a local rate limit rule with a token
+//   bucket algorithm. The ``RateLimitDescriptor`` is used to represent a list of symbols that
+//   are used to match against the rate limit rule.
+//
 message LocalRateLimitDescriptor {
   // Descriptor entries.
   repeated v3.RateLimitDescriptor.Entry entries = 1 [(validate.rules).repeated = {min_items: 1}];