Matchers: Add dynamic metadata to the http inputs (#34891)

fixes: https://github.com/envoyproxy/envoy/issues/34092

---------

Signed-off-by: Vikas Choudhary <choudharyvikas16@gmail.com>

Mirrored from https://github.com/envoyproxy/envoy @ 520d88e4cb4e8c5014531281a88dcc8076e18bfd

BUILD

@@ -291,6 +291,7 @@ proto_library(
         "//envoy/extensions/matching/common_inputs/ssl/v3:pkg",
         "//envoy/extensions/matching/input_matchers/consistent_hashing/v3:pkg",
         "//envoy/extensions/matching/input_matchers/ip/v3:pkg",
+        "//envoy/extensions/matching/input_matchers/metadata/v3:pkg",
         "//envoy/extensions/matching/input_matchers/runtime_fraction/v3:pkg",
         "//envoy/extensions/network/dns_resolver/apple/v3:pkg",
         "//envoy/extensions/network/dns_resolver/cares/v3:pkg",

envoy/extensions/matching/common_inputs/network/v3/network_inputs.proto

@@ -103,3 +103,48 @@ message ApplicationProtocolInput {
 message FilterStateInput {
   string key = 1 [(validate.rules).string = {min_len: 1}];
 }
+
+// Input that matches dynamic metadata by key.
+// DynamicMetadataInput provides a general interface using ``filter`` and ``path`` to retrieve value from
+// :ref:`Metadata <envoy_v3_api_msg_config.core.v3.Metadata>`.
+//
+// For example, for the following Metadata:
+//
+// .. code-block:: yaml
+//
+//    filter_metadata:
+//      envoy.xxx:
+//        prop:
+//          foo: bar
+//          xyz:
+//            hello: envoy
+//
+// The following DynamicMetadataInput will retrieve a string value "bar" from the Metadata.
+//
+// .. code-block:: yaml
+//
+//    filter: envoy.xxx
+//    path:
+//    - key: prop
+//    - key: foo
+//
+// [#extension: envoy.matching.inputs.dynamic_metadata]
+message DynamicMetadataInput {
+  // Specifies the segment in a path to retrieve value from Metadata.
+  // Note: Currently it's not supported to retrieve a value from a list in Metadata. This means that
+  // if the segment key refers to a list, it has to be the last segment in a path.
+  message PathSegment {
+    oneof segment {
+      option (validate.required) = true;
+
+      // If specified, use the key to retrieve the value in a Struct.
+      string key = 1 [(validate.rules).string = {min_len: 1}];
+    }
+  }
+
+  // The filter name to retrieve the Struct from the Metadata.
+  string filter = 1 [(validate.rules).string = {min_len: 1}];
+
+  // The path to retrieve the Value from the Struct.
+  repeated PathSegment path = 2 [(validate.rules).repeated = {min_items: 1}];
+}

envoy/extensions/matching/input_matchers/metadata/v3/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/type/matcher/v3:pkg",
+        "@com_github_cncf_xds//udpa/annotations:pkg",
+    ],
+)

envoy/extensions/matching/input_matchers/metadata/v3/metadata.proto

@@ -0,0 +1,26 @@
+syntax = "proto3";
+
+package envoy.extensions.matching.input_matchers.metadata.v3;
+
+import "envoy/type/matcher/v3/value.proto";
+
+import "udpa/annotations/status.proto";
+import "validate/validate.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.matching.input_matchers.metadata.v3";
+option java_outer_classname = "MetadataProto";
+option java_multiple_files = true;
+option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/matching/input_matchers/metadata/v3;metadatav3";
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: metadata matcher]
+// [#extension: envoy.matching.matchers.metadata_matcher]
+
+// Metadata matcher for metadata from http matching input data.
+message Metadata {
+  // The Metadata is matched if the value retrieved by metadata matching input is matched to this value.
+  type.matcher.v3.ValueMatcher value = 1 [(validate.rules).message = {required: true}];
+
+  // If true, the match result will be inverted.
+  bool invert = 4;
+}

versioning/BUILD

@@ -230,6 +230,7 @@ proto_library(
         "//envoy/extensions/matching/common_inputs/ssl/v3:pkg",
         "//envoy/extensions/matching/input_matchers/consistent_hashing/v3:pkg",
         "//envoy/extensions/matching/input_matchers/ip/v3:pkg",
+        "//envoy/extensions/matching/input_matchers/metadata/v3:pkg",
         "//envoy/extensions/matching/input_matchers/runtime_fraction/v3:pkg",
         "//envoy/extensions/network/dns_resolver/apple/v3:pkg",
         "//envoy/extensions/network/dns_resolver/cares/v3:pkg",