OpenTelemetry access logger support extension formatters (#34469)

* api change

Signed-off-by: zirain <zirain2009@gmail.com>

* implement

Signed-off-by: zirain <zirain2009@gmail.com>

* format

Signed-off-by: zirain <zirain2009@gmail.com>

* fix test

Signed-off-by: zirain <zirain2009@gmail.com>

* use Formatter::CommandParserPtr

Signed-off-by: zirain <zirain2009@gmail.com>

* changelogs

Signed-off-by: zirain <zirain2009@gmail.com>

* format

Signed-off-by: zirain <zirain2009@gmail.com>

---------

Signed-off-by: zirain <zirain2009@gmail.com>

Mirrored from https://github.com/envoyproxy/envoy @ 244feec4af4cceb5e331301f89dbbdeca6b84291

envoy/extensions/access_loggers/open_telemetry/v3/BUILD

@@ -6,6 +6,7 @@ licenses(["notice"])  # Apache 2
 
 api_proto_package(
     deps = [
+        "//envoy/config/core/v3:pkg",
         "//envoy/extensions/access_loggers/grpc/v3:pkg",
         "@com_github_cncf_xds//udpa/annotations:pkg",
         "@opentelemetry_proto//:common",

envoy/extensions/access_loggers/open_telemetry/v3/logs_service.proto

@@ -2,6 +2,7 @@ syntax = "proto3";
 
 package envoy.extensions.access_loggers.open_telemetry.v3;
 
+import "envoy/config/core/v3/extension.proto";
 import "envoy/extensions/access_loggers/grpc/v3/als.proto";
 
 import "opentelemetry/proto/common/v1/common.proto";
@@ -22,7 +23,7 @@ option (udpa.annotations.file_status).package_version_status = ACTIVE;
 // populate `opentelemetry.proto.collector.v1.logs.ExportLogsServiceRequest.resource_logs <https://github.com/open-telemetry/opentelemetry-proto/blob/main/opentelemetry/proto/collector/logs/v1/logs_service.proto>`_.
 // In addition, the request start time is set in the dedicated field.
 // [#extension: envoy.access_loggers.open_telemetry]
-// [#next-free-field: 7]
+// [#next-free-field: 8]
 message OpenTelemetryAccessLogConfig {
   // [#comment:TODO(itamarkam): add 'filter_state_objects_to_log' to logs.]
   grpc.v3.CommonGrpcAccessLogConfig common_config = 1 [(validate.rules).message = {required: true}];
@@ -51,4 +52,9 @@ message OpenTelemetryAccessLogConfig {
   // ``access_logs.open_telemetry_access_log.``. If non-empty, stats will be rooted at
   // ``access_logs.open_telemetry_access_log.<stat_prefix>.``.
   string stat_prefix = 6;
+
+  // Specifies a collection of Formatter plugins that can be called from the access log configuration.
+  // See the formatters extensions documentation for details.
+  // [#extension-category: envoy.formatter]
+  repeated config.core.v3.TypedExtensionConfig formatters = 7;
 }