extensions: add http bandwidth limit filter (#16358)

the filter smoothens the flow of data in both direction up to the specified bandwidth limit.

Risk Level: Low, new filter
Testing: UTs added. Adding more UTs and integration tests.
Docs Changes: Added
Release Notes: Added
Fixes #13604

Signed-off-by: Nitin Goyal <nigoyal@microsoft.com>

Mirrored from https://github.com/envoyproxy/envoy @ a467b0ef41864459f4b4ad76fad7e1efb06b0bf8

BUILD

@@ -177,6 +177,7 @@ proto_library(
         "//envoy/extensions/filters/http/admission_control/v3alpha:pkg",
         "//envoy/extensions/filters/http/aws_lambda/v3:pkg",
         "//envoy/extensions/filters/http/aws_request_signing/v3:pkg",
+        "//envoy/extensions/filters/http/bandwidth_limit/v3alpha:pkg",
         "//envoy/extensions/filters/http/buffer/v3:pkg",
         "//envoy/extensions/filters/http/cache/v3alpha:pkg",
         "//envoy/extensions/filters/http/cdn_loop/v3alpha:pkg",

STYLE.md

@@ -113,11 +113,11 @@ organization](#package-organization) above.
 To add an extension config to the API, the steps below should be followed:
 
 1. If this is still WiP and subject to breaking changes, use `vNalpha` instead of `vN` in steps
-   below. Refer to the [Cache filter config](envoy/extensions/filter/http/cache/v3alpha/cache.proto)
+   below. Refer to the [Cache filter config](envoy/extensions/filters/http/cache/v3alpha/cache.proto)
    as an example of `v3alpha`, and the
-   [Buffer filter config](envoy/extensions/filter/http/buffer/v3/buffer.proto) as an example of `v3`.
+   [Buffer filter config](envoy/extensions/filters/http/buffer/v3/buffer.proto) as an example of `v3`.
 1. Place the v3 extension configuration `.proto` in `api/envoy/extensions`, e.g.
-   `api/envoy/extensions/filter/http/foobar/v3/foobar.proto` together with an initial BUILD file:
+   `api/envoy/extensions/filters/http/foobar/v3/foobar.proto` together with an initial BUILD file:
    ```bazel
    load("@envoy_api//bazel:api_build_system.bzl", "api_proto_package")
 

envoy/extensions/filters/http/bandwidth_limit/v3alpha/BUILD

@@ -0,0 +1,12 @@
+# DO NOT EDIT. This file is generated by tools/proto_format/proto_sync.py.
+
+load("@envoy_api//bazel:api_build_system.bzl", "api_proto_package")
+
+licenses(["notice"])  # Apache 2
+
+api_proto_package(
+    deps = [
+        "//envoy/config/core/v3:pkg",
+        "@com_github_cncf_udpa//udpa/annotations:pkg",
+    ],
+)

envoy/extensions/filters/http/bandwidth_limit/v3alpha/bandwidth_limit.proto

@@ -0,0 +1,70 @@
+syntax = "proto3";
+
+package envoy.extensions.filters.http.bandwidth_limit.v3alpha;
+
+import "envoy/config/core/v3/base.proto";
+
+import "google/protobuf/duration.proto";
+import "google/protobuf/wrappers.proto";
+
+import "udpa/annotations/status.proto";
+import "validate/validate.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.filters.http.bandwidth_limit.v3alpha";
+option java_outer_classname = "BandwidthLimitProto";
+option java_multiple_files = true;
+option (udpa.annotations.file_status).work_in_progress = true;
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: Bandwidth limit]
+// Bandwidth limit :ref:`configuration overview <config_http_filters_bandwidth_limit>`.
+// [#extension: envoy.filters.http.bandwidth_limit]
+
+// [#next-free-field: 6]
+message BandwidthLimit {
+  // Defines the mode for the bandwidth limit filter.
+  // Values represent bitmask.
+  enum EnableMode {
+    // Filter is disabled.
+    DISABLED = 0;
+
+    // Filter enabled only for incoming traffic.
+    REQUEST = 1;
+
+    // Filter enabled only for outgoing traffic.
+    RESPONSE = 2;
+
+    // Filter enabled for both incoming and outgoing traffic.
+    REQUEST_AND_RESPONSE = 3;
+  }
+
+  // The human readable prefix to use when emitting stats.
+  string stat_prefix = 1 [(validate.rules).string = {min_len: 1}];
+
+  // The enable mode for the bandwidth limit filter.
+  // Default is Disabled.
+  EnableMode enable_mode = 2 [(validate.rules).enum = {defined_only: true}];
+
+  // The limit supplied in KiB/s.
+  //
+  // .. note::
+  //   It's fine for the limit to be unset for the global configuration since the bandwidth limit
+  //   can be applied at a the virtual host or route level. Thus, the limit must be set for the
+  //   per route configuration otherwise the config will be rejected.
+  //
+  // .. note::
+  //   When using per route configuration, the limit becomes unique to that route.
+  //
+  google.protobuf.UInt64Value limit_kbps = 3 [(validate.rules).uint64 = {gte: 1}];
+
+  // Optional Fill interval in milliseconds for the token refills. Defaults to 50ms.
+  // It must be at least 20ms to avoid too aggressive refills.
+  google.protobuf.Duration fill_interval = 4 [(validate.rules).duration = {
+    lte {seconds: 1}
+    gte {nanos: 20000000}
+  }];
+
+  // Runtime flag that controls whether the filter is enabled or not. If not specified, defaults
+  // to enabled.
+  config.core.v3.RuntimeFeatureFlag runtime_enabled = 5;
+}

versioning/BUILD

@@ -60,6 +60,7 @@ proto_library(
         "//envoy/extensions/filters/http/admission_control/v3alpha:pkg",
         "//envoy/extensions/filters/http/aws_lambda/v3:pkg",
         "//envoy/extensions/filters/http/aws_request_signing/v3:pkg",
+        "//envoy/extensions/filters/http/bandwidth_limit/v3alpha:pkg",
         "//envoy/extensions/filters/http/buffer/v3:pkg",
         "//envoy/extensions/filters/http/cache/v3alpha:pkg",
         "//envoy/extensions/filters/http/cdn_loop/v3alpha:pkg",