Watchdog action that will signal a particular thread to abort.

CODEOWNERS

@@ -130,6 +130,7 @@ extensions/filters/common/original_src @snowp @klarose
 /*/extensions/filters/http/decompressor @rojkov @dio
 # Watchdog Extensions
 /*/extensions/watchdog/profile_action @kbaichoo @htuch
+/*/extensions/watchdog/abort_action @kbaichoo @htuch
 # Core upstream code
 extensions/upstreams/http @alyssawilk @snowp @mattklein123
 extensions/upstreams/http/http @alyssawilk @snowp @mattklein123

api/BUILD

@@ -245,6 +245,7 @@ proto_library(
         "//envoy/extensions/upstreams/http/http/v3:pkg",
         "//envoy/extensions/upstreams/http/tcp/v3:pkg",
         "//envoy/extensions/wasm/v3:pkg",
+        "//envoy/extensions/watchdog/abort_action/v3alpha:pkg",
         "//envoy/extensions/watchdog/profile_action/v3alpha:pkg",
         "//envoy/service/accesslog/v3:pkg",
         "//envoy/service/auth/v3:pkg",

api/envoy/extensions/watchdog/abort_action/v3alpha/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"],
+)

api/envoy/extensions/watchdog/abort_action/v3alpha/abort_action.proto

@@ -0,0 +1,32 @@
+syntax = "proto3";
+
+package envoy.extensions.watchdog.abort_action.v3alpha;
+
+import "google/protobuf/duration.proto";
+
+import "udpa/annotations/status.proto";
+import "udpa/annotations/versioning.proto";
+import "validate/validate.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.watchdog.abort_action.v3alpha";
+option java_outer_classname = "AbortActionProto";
+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: Watchdog Action that sends a SIGABRT to kill the process.]
+// [#extension: envoy.watchdog.abort_action]
+
+// A GuardDogAction that will terminate the process by sending SIGABRT to the
+// stuck thread. This would allow easier access to the call stack of the stuck
+// thread since we would run signal handlers on that thread. This would be
+// more useful than the default watchdog kill behaviors since those PANIC
+// from the watchdog's thread.
+
+// This is currently only implemented for systems that support kill to send
+// signals.
+message AbortActionConfig {
+  // How long to wait for the thread to respond to the SIGABRT before killing the
+  // process from this action. This is a blocking action.
+  google.protobuf.Duration wait_duration = 1;
+}

api/versioning/BUILD

@@ -128,6 +128,7 @@ proto_library(
         "//envoy/extensions/upstreams/http/http/v3:pkg",
         "//envoy/extensions/upstreams/http/tcp/v3:pkg",
         "//envoy/extensions/wasm/v3:pkg",
+        "//envoy/extensions/watchdog/abort_action/v3alpha:pkg",
         "//envoy/extensions/watchdog/profile_action/v3alpha:pkg",
         "//envoy/service/accesslog/v3:pkg",
         "//envoy/service/auth/v3:pkg",

bazel/repositories.bzl

@@ -12,6 +12,7 @@ WINDOWS_SKIP_TARGETS = [
     "envoy.tracers.lightstep",
     "envoy.tracers.datadog",
     "envoy.tracers.opencensus",
+    "envoy.watchdog.abort_action",
 ]
 
 # Make all contents of an external repository accessible under a filegroup.  Used for external HTTP

docs/root/api-v3/config/watchdog/watchdog.rst

@@ -6,3 +6,4 @@ Watchdog
   :maxdepth: 2
 
   ../../extensions/watchdog/profile_action/v3alpha/*
+  ../../extensions/watchdog/abort_action/v3alpha/*

docs/root/version_history/current.rst

@@ -119,6 +119,7 @@ New Features
 * watchdog: support randomizing the watchdog's kill timeout to prevent synchronized kills via a maximium jitter parameter :ref:`max_kill_timeout_jitter<envoy_v3_api_field_config.bootstrap.v3.Watchdog.max_kill_timeout_jitter>`.
 * watchdog: supports an extension point where actions can be registered to fire on watchdog events such as miss, megamiss, kill and multikill. See ref:`watchdog actions<envoy_v3_api_field_config.bootstrap.v3.Watchdog.actions>`.
 * watchdog: watchdog action extension that does cpu profiling. See ref:`Profile Action <envoy_v3_api_file_envoy/extensions/watchdog/profile_action/v3alpha/profile_action.proto>`.
+* watchdog: watchdog action extension that sends SIGABRT to the stuck thread to terminate the process. See ref:`Abort Action <envoy_v3_api_file_envoy/extensions/watchdog/abort_action/v3alpha/abort_action.proto>`.
 * xds: added :ref:`extension config discovery<envoy_v3_api_msg_config.core.v3.ExtensionConfigSource>` support for HTTP filters.
 * zlib: added option to use `zlib-ng <https://github.com/zlib-ng/zlib-ng>`_ as zlib library.
 

include/envoy/server/guarddog_config.h

@@ -27,13 +27,14 @@ class GuardDogAction {
   /**
    * Callback function for when the GuardDog observes an event.
    * @param event the event the GuardDog observes.
-   * @param thread_ltt_pairs pairs of the relevant thread to the event, and the
-   *  last time touched (LTT) of those threads with their watchdog.
+   * @param thread_last_checkin_pairs pair of the relevant thread to the event, and the
+   *  last check in time of those threads with their watchdog.
    * @param now the current time.
    */
-  virtual void run(envoy::config::bootstrap::v3::Watchdog::WatchdogAction::WatchdogEvent event,
-                   const std::vector<std::pair<Thread::ThreadId, MonotonicTime>>& thread_ltt_pairs,
-                   MonotonicTime now) PURE;
+  virtual void
+  run(envoy::config::bootstrap::v3::Watchdog::WatchdogAction::WatchdogEvent event,
+      const std::vector<std::pair<Thread::ThreadId, MonotonicTime>>& thread_last_checkin_pairs,
+      MonotonicTime now) PURE;
 };
 
 using GuardDogActionPtr = std::unique_ptr<GuardDogAction>;

source/extensions/extensions_build_config.bzl

@@ -203,6 +203,7 @@ EXTENSIONS = {
     # Watchdog actions
     #
     "envoy.watchdog.profile_action":                    "//source/extensions/watchdog/profile_action:config",
+    "envoy.watchdog.abort_action":                      "//source/extensions/watchdog/abort_action:config",
 
 }
 

source/extensions/watchdog/abort_action/BUILD

@@ -0,0 +1,40 @@
+load(
+    "//bazel:envoy_build_system.bzl",
+    "envoy_cc_extension",
+    "envoy_cc_library",
+    "envoy_extension_package",
+)
+
+licenses(["notice"])  # Apache 2
+
+envoy_extension_package()
+
+envoy_cc_library(
+    name = "abort_action_lib",
+    srcs = ["abort_action.cc"],
+    hdrs = ["abort_action.h"],
+    deps = [
+        "//include/envoy/common:time_interface",
+        "//include/envoy/server:guarddog_config_interface",
+        "//include/envoy/thread:thread_interface",
+        "//source/common/common:assert_lib",
+        "//source/common/protobuf:utility_lib",
+        "@envoy_api//envoy/extensions/watchdog/abort_action/v3alpha:pkg_cc_proto",
+    ],
+)
+
+envoy_cc_extension(
+    name = "config",
+    srcs = ["config.cc"],
+    hdrs = ["config.h"],
+    security_posture = "data_plane_agnostic",
+    status = "alpha",
+    deps = [
+        ":abort_action_lib",
+        "//include/envoy/registry",
+        "//source/common/config:utility_lib",
+        "//source/common/protobuf",
+        "//source/common/protobuf:message_validator_lib",
+        "@envoy_api//envoy/extensions/watchdog/abort_action/v3alpha:pkg_cc_proto",
+    ],
+)

source/extensions/watchdog/abort_action/abort_action.cc

@@ -0,0 +1,65 @@
+#include "extensions/watchdog/abort_action/abort_action.h"
+
+#include <sys/types.h>
+
+#include <csignal>
+
+#include "envoy/thread/thread.h"
+
+#include "common/common/assert.h"
+#include "common/common/fmt.h"
+#include "common/common/logger.h"
+#include "common/protobuf/utility.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace Watchdog {
+namespace AbortAction {
+namespace {
+#ifdef __linux__
+pid_t toPlatformTid(int64_t tid) { return static_cast<pid_t>(tid); }
+#elif defined(__APPLE__)
+uint64_t toPlatformTid(int64_t tid) { return static_cast<uint64_t>(tid); }
+#endif
+} // namespace
+
+AbortAction::AbortAction(
+    envoy::extensions::watchdog::abort_action::v3alpha::AbortActionConfig& config,
+    Server::Configuration::GuardDogActionFactoryContext& /*context*/)
+    : config_(config){};
+
+void AbortAction::run(
+    envoy::config::bootstrap::v3::Watchdog::WatchdogAction::WatchdogEvent /*event*/,
+    const std::vector<std::pair<Thread::ThreadId, MonotonicTime>>& thread_last_checkin_pairs,
+    MonotonicTime /*now*/) {
+
+  if (thread_last_checkin_pairs.empty()) {
+    ENVOY_LOG_MISC(warn, "Watchdog AbortAction called without any thread.");
+    return;
+  }
+
+  int64_t raw_tid = thread_last_checkin_pairs[0].first.getId();
+
+  // Assume POSIX-compatible system and signal to the thread.
+  ENVOY_LOG_MISC(error, "Watchdog AbortAction sending abort signal to thread with tid {}.",
+                 raw_tid);
+
+  if (kill(toPlatformTid(raw_tid), SIGABRT) == 0) {
+    // Successfully sent signal, sleep for wait_duration.
+    absl::SleepFor(absl::Milliseconds(PROTOBUF_GET_MS_OR_DEFAULT(config_, wait_duration, 0)));
+  } else {
+    // Failed to send the signal, abort?
+    ENVOY_LOG_MISC(error, "Failed to send signal to tid {}", raw_tid);
+  }
+
+  // Abort from the action since the signaled thread hasn't yet crashed the process.
+  // panicing in the action gives flexibility since it doesn't depend on
+  // external code to kill the process if the signal fails.
+  PANIC(fmt::format("Failed to kill thread with id {}, aborting from Watchdog AbortAction instead.",
+                    raw_tid));
+}
+
+} // namespace AbortAction
+} // namespace Watchdog
+} // namespace Extensions
+} // namespace Envoy

source/extensions/watchdog/abort_action/abort_action.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <chrono>
+
+#include "envoy/extensions/watchdog/abort_action/v3alpha/abort_action.pb.h"
+#include "envoy/server/guarddog_config.h"
+#include "envoy/thread/thread.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace Watchdog {
+namespace AbortAction {
+
+/**
+ * A GuardDogAction that will terminate the process by sending SIGABRT to the
+ * stuck thread. This is currently only implemented for systems that
+ * support kill to send signals.
+ */
+class AbortAction : public Server::Configuration::GuardDogAction {
+public:
+  AbortAction(envoy::extensions::watchdog::abort_action::v3alpha::AbortActionConfig& config,
+              Server::Configuration::GuardDogActionFactoryContext& context);
+
+  void run(envoy::config::bootstrap::v3::Watchdog::WatchdogAction::WatchdogEvent event,
+           const std::vector<std::pair<Thread::ThreadId, MonotonicTime>>& thread_last_checkin_pairs,
+           MonotonicTime now) override;
+
+private:
+  const envoy::extensions::watchdog::abort_action::v3alpha::AbortActionConfig config_;
+};
+
+using AbortActionPtr = std::unique_ptr<AbortAction>;
+
+} // namespace AbortAction
+} // namespace Watchdog
+} // namespace Extensions
+} // namespace Envoy

source/extensions/watchdog/abort_action/config.cc

@@ -0,0 +1,32 @@
+#include "extensions/watchdog/abort_action/config.h"
+
+#include "envoy/registry/registry.h"
+
+#include "common/config/utility.h"
+#include "common/protobuf/message_validator_impl.h"
+
+#include "extensions/watchdog/abort_action/abort_action.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace Watchdog {
+namespace AbortAction {
+
+Server::Configuration::GuardDogActionPtr AbortActionFactory::createGuardDogActionFromProto(
+    const envoy::config::bootstrap::v3::Watchdog::WatchdogAction& config,
+    Server::Configuration::GuardDogActionFactoryContext& context) {
+  auto message = createEmptyConfigProto();
+  Config::Utility::translateOpaqueConfig(config.config().typed_config(), ProtobufWkt::Struct(),
+                                         ProtobufMessage::getStrictValidationVisitor(), *message);
+  return std::make_unique<AbortAction>(dynamic_cast<AbortActionConfig&>(*message), context);
+}
+
+/**
+ * Static registration for the fixed heap resource monitor factory. @see RegistryFactory.
+ */
+REGISTER_FACTORY(AbortActionFactory, Server::Configuration::GuardDogActionFactory);
+
+} // namespace AbortAction
+} // namespace Watchdog
+} // namespace Extensions
+} // namespace Envoy

source/extensions/watchdog/abort_action/config.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#include "envoy/extensions/watchdog/abort_action/v3alpha/abort_action.pb.h"
+#include "envoy/server/guarddog_config.h"
+
+#include "common/protobuf/protobuf.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace Watchdog {
+namespace AbortAction {
+
+class AbortActionFactory : public Server::Configuration::GuardDogActionFactory {
+public:
+  AbortActionFactory() = default;
+
+  Server::Configuration::GuardDogActionPtr createGuardDogActionFromProto(
+      const envoy::config::bootstrap::v3::Watchdog::WatchdogAction& config,
+      Server::Configuration::GuardDogActionFactoryContext& context) override;
+
+  ProtobufTypes::MessagePtr createEmptyConfigProto() override {
+    return std::make_unique<AbortActionConfig>();
+  }
+
+  std::string name() const override { return "envoy.watchdog.abort_action"; }
+
+  using AbortActionConfig = envoy::extensions::watchdog::abort_action::v3alpha::AbortActionConfig;
+};
+
+} // namespace AbortAction
+} // namespace Watchdog
+} // namespace Extensions
+} // namespace Envoy

source/extensions/watchdog/profile_action/profile_action.cc

@@ -49,14 +49,14 @@ ProfileAction::ProfileAction(
 
 void ProfileAction::run(
     envoy::config::bootstrap::v3::Watchdog::WatchdogAction::WatchdogEvent /*event*/,
-    const std::vector<std::pair<Thread::ThreadId, MonotonicTime>>& thread_ltt_pairs,
+    const std::vector<std::pair<Thread::ThreadId, MonotonicTime>>& thread_last_checkin_pairs,
     MonotonicTime /*now*/) {
   if (running_profile_) {
     return;
   }
 
   // Check if there's a tid that justifies profiling
-  if (thread_ltt_pairs.empty()) {
+  if (thread_last_checkin_pairs.empty()) {
     ENVOY_LOG_MISC(warn, "Profile Action: No tids were provided.");
     return;
   }

source/extensions/watchdog/profile_action/profile_action.h

@@ -22,7 +22,7 @@ class ProfileAction : public Server::Configuration::GuardDogAction {
                 Server::Configuration::GuardDogActionFactoryContext& context);
 
   void run(envoy::config::bootstrap::v3::Watchdog::WatchdogAction::WatchdogEvent event,
-           const std::vector<std::pair<Thread::ThreadId, MonotonicTime>>& thread_ltt_pairs,
+           const std::vector<std::pair<Thread::ThreadId, MonotonicTime>>& thread_last_checkin_pairs,
            MonotonicTime now) override;
 
 private: