// Copyright 2025 Envoy Project Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//     http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

syntax = "proto3";

package envoy.extensions.dynamic_modules.v3;

import "udpa/annotations/status.proto";
import "validate/validate.proto";

option java_package = "io.envoyproxy.envoy.extensions.dynamic_modules.v3";
option java_outer_classname = "DynamicModulesProto";
option java_multiple_files = true;
option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/dynamic_modules/v3;dynamic_modulesv3";
option (udpa.annotations.file_status).package_version_status = ACTIVE;

// [#protodoc-title: Dynamic Modules common configuration]

// Configuration of a dynamic module. A dynamic module is a shared object file that can be loaded via dlopen
// by various Envoy extension points. Currently, only HTTP filter (envoy.filters.http.dynamic_modules) is supported.
//
// How a module is loaded is determined by the extension point that uses it. For example, the HTTP filter
// loads the module with dlopen when Envoy receives a configuration that references the module at load time.
// If loading the module fails, the configuration will be rejected.
//
// Whether or not the shared object is the same is determined by the file path as well as the file's inode depending
// on the platform. Notably, if the file path and the content of the file are the same, the shared object will be reused.
//
// A module must be compatible with the ABI specified in :repo:`abi.h <source/extensions/dynamic_modules/abi.h>`.
// Currently, compatibility is only guaranteed by an exact version match between the Envoy
// codebase and the dynamic module SDKs. In the future, after the ABI is stabilized, we will revisit
// this restriction and hopefully provide a wider compatibility guarantee. Until then, Envoy
// checks the hash of the ABI header files to ensure that the dynamic modules are built against the
// same version of the ABI.
message DynamicModuleConfig {
  // The name of the dynamic module. The client is expected to have some configuration indicating where to search for the module.
  // In Envoy, the search path can only be configured via the environment variable ``ENVOY_DYNAMIC_MODULES_SEARCH_PATH``.
  // The actual search path is ``${ENVOY_DYNAMIC_MODULES_SEARCH_PATH}/lib${name}.so``. TODO: make the search path configurable via
  // command line options.
  string name = 1 [(validate.rules).string = {min_len: 1}];

  // Set true to prevent the module from being unloaded with dlclose.
  // This is useful for modules that have global state that should not be unloaded.
  // A module is closed when no more references to it exist in the process. For example,
  // no HTTP filters are using the module (e.g. after configuration update).
  bool do_not_close = 3;
}
