wasm: remove unused Istio specific Wasm code under src.

src/envoy/extensions/wasm/BUILD

@@ -29,8 +29,6 @@ envoy_cc_library(
     visibility = ["//visibility:public"],
     deps = [
         "@envoy//source/common/stats:stats_lib",
-        "@envoy//source/common/version:version_lib",
-        "@envoy//source/extensions/common/wasm:wasm_hdr",
         "@envoy//source/server/admin:prometheus_stats_lib",
     ],
 )

src/envoy/extensions/wasm/wasm.cc

@@ -12,143 +12,27 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-#include "source/extensions/common/wasm/wasm.h"
-
 #include "source/common/stats/utility.h"
-#include "source/common/version/version.h"
 #include "source/server/admin/prometheus_stats.h"
 
 namespace Envoy {
 namespace Extensions {
 namespace Common {
 namespace Wasm {
 namespace Istio {
-namespace {
-
-struct ConfigStats {
-  ConfigStats(Stats::SymbolTable& symbol_table)
-      : stat_name_pool_(symbol_table) {}
-  Stats::StatNamePool stat_name_pool_;
-  // NB: Use pointers because references must be initialized in the
-  // initialization list which then would then require that all the component
-  // stat names to be member variables because stat_name_pool_.add() does not
-  // dedup so we can not create them as temporaries.
-  Stats::Counter* permanent_read_error_;
-  Stats::Counter* eventually_consistent_read_;
-  Stats::Counter* invalid_module_;
-  Stats::Counter* invalid_configuration_;
-};
-
-}  // namespace
 
-class IstioWasmExtension : public EnvoyWasm {
+// Stat prefix cannot be configured dynamically.
+// https://github.com/envoyproxy/envoy/issues/14920
+// https://github.com/istio/istio/issues/27635
+class RegisterPrometheusNamespace {
  public:
-  IstioWasmExtension() {
+  RegisterPrometheusNamespace() {
     ::Envoy::Server::PrometheusStatsFormatter::registerPrometheusNamespace(
         "istio");
   }
-  ~IstioWasmExtension() override = default;
-  void onEvent(WasmEvent event, const PluginSharedPtr& plugin) override;
-  void onRemoteCacheEntriesChanged(int remote_cache_entries) override;
-  void createStats(const Stats::ScopeSharedPtr& scope,
-                   const PluginSharedPtr& plugin) override;
-  void resetStats() override;
-
- private:
-  std::map<std::string, std::unique_ptr<ConfigStats>> config_stats_;
 };
 
-static std::string statsKey(const PluginSharedPtr& plugin) {
-  auto sep = std::string("\t");
-  return plugin->name_ + sep + plugin->runtime_;
-}
-
-void IstioWasmExtension::onEvent(WasmEvent event,
-                                 const PluginSharedPtr& plugin) {
-  EnvoyWasm::onEvent(event, plugin);
-  auto key = statsKey(plugin);
-  auto& stats = config_stats_.at(key);
-  switch (event) {
-    case EnvoyWasm::WasmEvent::Ok:
-    case EnvoyWasm::WasmEvent::RemoteLoadCacheHit:
-      break;
-    case EnvoyWasm::WasmEvent::RemoteLoadCacheNegativeHit:
-      stats->permanent_read_error_->inc();
-      break;
-    case EnvoyWasm::WasmEvent::RemoteLoadCacheMiss:
-      stats->eventually_consistent_read_->inc();
-      break;
-    case EnvoyWasm::WasmEvent::RemoteLoadCacheFetchSuccess:
-      break;
-    case EnvoyWasm::WasmEvent::RemoteLoadCacheFetchFailure:
-      stats->permanent_read_error_->inc();
-      break;
-    case EnvoyWasm::WasmEvent::UnableToCreateVM:
-    case EnvoyWasm::WasmEvent::UnableToCloneVM:
-    case EnvoyWasm::WasmEvent::MissingFunction:
-    case EnvoyWasm::WasmEvent::UnableToInitializeCode:
-      stats->invalid_module_->inc();
-      break;
-    case EnvoyWasm::WasmEvent::StartFailed:
-    case EnvoyWasm::WasmEvent::ConfigureFailed:
-      stats->invalid_configuration_->inc();
-      break;
-    case EnvoyWasm::WasmEvent::RuntimeError:
-      break;
-  }
-}
-
-void IstioWasmExtension::onRemoteCacheEntriesChanged(int entries) {
-  EnvoyWasm::onRemoteCacheEntriesChanged(entries);
-}
-
-// NB: the "scope" here is tied to the lifetime of the filter chain in many
-// cases and may disappear. Code in envoy detects that and will call
-// resetStats().
-void IstioWasmExtension::createStats(const Stats::ScopeSharedPtr& scope,
-                                     const PluginSharedPtr& plugin) {
-  EnvoyWasm::createStats(scope, plugin);
-  std::string istio_version = Envoy::VersionInfo::version();
-  auto node_metadata_fields = plugin->localInfo().node().metadata().fields();
-  auto istio_version_it = node_metadata_fields.find("ISTIO_VERSION");
-  if (istio_version_it != node_metadata_fields.end()) {
-    istio_version = istio_version_it->second.string_value();
-  }
-  auto key = statsKey(plugin);
-  if (config_stats_.find(key) == config_stats_.end()) {
-    auto new_stats = std::make_unique<ConfigStats>(scope->symbolTable());
-    auto& pool = new_stats->stat_name_pool_;
-    auto prefix = pool.add("istio_wasm_config_errors_total");
-    auto error_type = pool.add("error_type");
-    auto plugin_name = pool.add("plugin_name");
-    auto name = pool.add(plugin->name_);
-    auto proxy_version = pool.add("proxy_version");
-    auto version = pool.add(istio_version);
-    auto vm = pool.add("vm");
-    auto runtime = pool.add(plugin->runtime_);
-    new_stats->permanent_read_error_ = &Stats::Utility::counterFromElements(
-        *scope, {prefix, error_type, pool.add("permanent_read_errors"),
-                 plugin_name, name, proxy_version, version, vm, runtime});
-    new_stats->eventually_consistent_read_ =
-        &Stats::Utility::counterFromElements(
-            *scope, {prefix, error_type, pool.add("eventually_consistent_read"),
-                     plugin_name, name, proxy_version, version, vm, runtime});
-    new_stats->invalid_module_ = &Stats::Utility::counterFromElements(
-        *scope, {prefix, error_type, pool.add("invalid_module"), plugin_name,
-                 name, proxy_version, version, vm, runtime});
-    new_stats->invalid_configuration_ = &Stats::Utility::counterFromElements(
-        *scope, {prefix, error_type, pool.add("invalid_configuration"),
-                 plugin_name, name, proxy_version, version, vm, runtime});
-    config_stats_[key] = std::move(new_stats);
-  }
-}
-
-void IstioWasmExtension::resetStats() {
-  EnvoyWasm::resetStats();
-  config_stats_.clear();
-}
-
-REGISTER_WASM_EXTENSION(IstioWasmExtension);
+RegisterPrometheusNamespace register_namespace;
 
 }  // namespace Istio
 }  // namespace Wasm