filters: Add dependencies.proto (#14750)

Introduces the FilterDependency proto. This isn't quite an extension, but it's a common proto to be used by all filter extensions.

Risk Level: Low (proto addition only)

#14470

Signed-off-by: Auni Ahsan <auni@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 2da224f88afe5ec84ba802bd932f73ed13308a92

BUILD

@@ -166,6 +166,7 @@ proto_library(
         "//envoy/extensions/common/tap/v3:pkg",
         "//envoy/extensions/compression/gzip/compressor/v3:pkg",
         "//envoy/extensions/compression/gzip/decompressor/v3:pkg",
+        "//envoy/extensions/filters/common/dependency/v3:pkg",
         "//envoy/extensions/filters/common/fault/v3:pkg",
         "//envoy/extensions/filters/common/matcher/action/v3:pkg",
         "//envoy/extensions/filters/http/adaptive_concurrency/v3:pkg",

envoy/extensions/filters/common/dependency/v3/BUILD

@@ -0,0 +1,9 @@
+# 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 = ["@com_github_cncf_udpa//udpa/annotations:pkg"],
+)

envoy/extensions/filters/common/dependency/v3/dependency.proto

@@ -0,0 +1,45 @@
+syntax = "proto3";
+
+package envoy.extensions.filters.common.dependency.v3;
+
+import "udpa/annotations/migrate.proto";
+import "udpa/annotations/status.proto";
+import "validate/validate.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.filters.common.dependency.v3";
+option java_outer_classname = "DependencyProto";
+option java_multiple_files = true;
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: Filter dependency specification]
+
+// Dependency specification and string identifier.
+message Dependency {
+  enum DependencyType {
+    HEADER = 0;
+    FILTER_STATE_KEY = 1;
+    DYNAMIC_METADATA = 2;
+  }
+
+  // The kind of dependency.
+  DependencyType type = 1;
+
+  // The string identifier for the dependency.
+  string name = 2 [(validate.rules).string = {min_len: 1}];
+}
+
+// Dependency specification for a filter. For a filter chain to be valid, any
+// dependency that is required must be provided by an earlier filter.
+message FilterDependencies {
+  // A list of dependencies required on the decode path.
+  repeated Dependency decode_required = 1;
+
+  // A list of dependencies provided on the encode path.
+  repeated Dependency decode_provided = 2;
+
+  // A list of dependencies required on the decode path.
+  repeated Dependency encode_required = 3;
+
+  // A list of dependencies provided on the encode path.
+  repeated Dependency encode_provided = 4;
+}

versioning/BUILD

@@ -49,6 +49,7 @@ proto_library(
         "//envoy/extensions/common/tap/v3:pkg",
         "//envoy/extensions/compression/gzip/compressor/v3:pkg",
         "//envoy/extensions/compression/gzip/decompressor/v3:pkg",
+        "//envoy/extensions/filters/common/dependency/v3:pkg",
         "//envoy/extensions/filters/common/fault/v3:pkg",
         "//envoy/extensions/filters/common/matcher/action/v3:pkg",
         "//envoy/extensions/filters/http/adaptive_concurrency/v3:pkg",