tracing: Support OpenTracing API

bazel/external/BUILD

@@ -4,7 +4,8 @@ cc_library(
     name = "all_external",
     srcs = [":empty.cc"],
     deps = [
-        "@com_github_lightstep_lightstep_tracer_cpp//:lightstep",
+        "@io_opentracing_cpp//:opentracing",
+        "@com_github_lightstep_lightstep_tracer_cpp//:lightstep_tracer",
         "@com_google_googletest//:gtest",
     ],
 )

bazel/repositories.bzl

@@ -238,6 +238,7 @@ def envoy_dependencies(path = "@envoy_deps//", skip_targets = []):
     _com_github_fmtlib_fmt()
     _com_github_gabime_spdlog()
     _com_github_gcovr_gcovr()
+    _io_opentracing_cpp()
     _com_github_lightstep_lightstep_tracer_cpp()
     _com_github_nodejs_http_parser()
     _com_github_tencent_rapidjson()
@@ -312,23 +313,22 @@ def _com_github_gcovr_gcovr():
         actual = "@com_github_gcovr_gcovr//:gcovr",
     )
 
+def _io_opentracing_cpp():
+    _repository_impl("io_opentracing_cpp")
+    native.bind(
+        name = "opentracing",
+        actual = "@io_opentracing_cpp//:opentracing",
+    )
+
 def _com_github_lightstep_lightstep_tracer_cpp():
-    location = REPOSITORY_LOCATIONS[
-        "com_github_lightstep_lightstep_tracer_cpp"]
-    genrule_repository(
-        name = "com_github_lightstep_lightstep_tracer_cpp",
-        urls = location["urls"],
-        sha256 = location["sha256"],
-        strip_prefix = location["strip_prefix"],
-        patches = [
-            "@envoy//bazel/external:lightstep-missing-header.patch",
-        ],
-        genrule_cmd_file = "@envoy//bazel/external:lightstep.genrule_cmd",
-        build_file = "@envoy//bazel/external:lightstep.BUILD",
+    _repository_impl("com_github_lightstep_lightstep_tracer_cpp")
+    _repository_impl(
+        name = "lightstep_vendored_googleapis",
+        build_file = "@com_github_lightstep_lightstep_tracer_cpp//:lightstep-tracer-common/third_party/googleapis/BUILD",
     )
     native.bind(
         name = "lightstep",
-        actual = "@com_github_lightstep_lightstep_tracer_cpp//:lightstep",
+        actual = "@com_github_lightstep_lightstep_tracer_cpp//:lightstep_tracer",
     )
 
 def _com_github_tencent_rapidjson():

bazel/repository_locations.bzl

@@ -25,10 +25,17 @@ REPOSITORY_LOCATIONS = dict(
         commit = "c0d77201039c7b119b18bc7fb991564c602dd75d",
         remote = "https://github.com/gcovr/gcovr",
     ),
+    io_opentracing_cpp = dict(
+        commit = "550c686e0e174c845a034f432a6c31a808f5f994",
+        remote = "https://github.com/opentracing/opentracing-cpp",
+    ),
     com_github_lightstep_lightstep_tracer_cpp = dict(
-        sha256 = "f7477e67eca65f904c0b90a6bfec46d58cccfc998a8e75bc3259b6e93157ff84",
-        strip_prefix = "lightstep-tracer-cpp-0.36",
-        urls = ["https://github.com/lightstep/lightstep-tracer-cpp/releases/download/v0_36/lightstep-tracer-cpp-0.36.tar.gz"],
+        commit = "deb5284395075028c3e5b4eab1416fe1e597bdb7",
+        remote = "https://github.com/lightstep/lightstep-tracer-cpp",
+    ),
+    lightstep_vendored_googleapis = dict(
+        commit = "d6f78d948c53f3b400bb46996eb3084359914f9b",
+        remote = "https://github.com/google/googleapis",
     ),
     com_github_nodejs_http_parser = dict(
         commit = "feae95a3a69f111bc1897b9048d9acbc290992f9",  # v2.7.1

ci/build_container/Makefile

@@ -52,6 +52,3 @@ $(THIRDPARTY_DEPS)/%.dep: $(RECIPES)/%.sh
 
 # Special support for targets that need protobuf, and hence take a dependency on protobuf.dep.
 PROTOBUF_BUILD ?= $(THIRDPARTY_BUILD)/$(if $(BUILD_DISTINCT),protobuf.dep,)
-
-$(THIRDPARTY_DEPS)/lightstep.dep: $(RECIPES)/lightstep.sh $(THIRDPARTY_DEPS)/protobuf.dep
-	@+$(call build-recipe,PROTOBUF_BUILD=$(PROTOBUF_BUILD))

include/envoy/http/header_map.h

@@ -355,7 +355,7 @@ class HeaderMap {
   /**
    * Get a header by key.
    * @param key supplies the header key.
-   * @return the header entry if it exsits otherwise nullptr.
+   * @return the header entry if it exists otherwise nullptr.
    */
   virtual const HeaderEntry* get(const LowerCaseString& key) const PURE;
 
@@ -384,6 +384,18 @@ class HeaderMap {
    */
   virtual void iterateReverse(ConstIterateCb cb, void* context) const PURE;
 
+  enum class Lookup { Found, NotFound, NotSupported };
+
+  /**
+   * Lookup one of the predefined inline headers (see ALL_INLINE_HEADERS below) by key.
+   * @param key supplies the header key.
+   * @param entry is set to the header entry if it exists and if key is one of the predefined inline
+   * headers; otherwise, nullptr.
+   * @return Lookup::Found if lookup was successful, Lookup::NotFound if the header entry doesn't
+   * exist, or Lookup::NotSupported if key is not one of the predefined inline headers.
+   */
+  virtual Lookup lookup(const LowerCaseString& key, const HeaderEntry** entry) const PURE;
+
   /**
    * Remove all instances of a header by key.
    * @param key supplies the header key to remove.

source/common/common/logger.h

@@ -38,6 +38,7 @@ namespace Logger {
   FUNCTION(router)               \
   FUNCTION(runtime)              \
   FUNCTION(testing)              \
+  FUNCTION(tracing)              \
   FUNCTION(upstream)
 
 enum class Id {

source/common/common/utility.cc

@@ -32,6 +32,17 @@ std::string DateFormatter::now() {
 ProdSystemTimeSource ProdSystemTimeSource::instance_;
 ProdMonotonicTimeSource ProdMonotonicTimeSource::instance_;
 
+ConstMemoryStreamBuffer::ConstMemoryStreamBuffer(const char* data, size_t size) {
+  // std::streambuf won't modify `data`, but the interface still requires a char* for convenience,
+  // so we need to const_cast.
+  char* ptr = const_cast<char*>(data);
+
+  this->setg(ptr, ptr, ptr + size);
+}
+
+InputConstMemoryStream::InputConstMemoryStream(const char* data, size_t size)
+    : ConstMemoryStreamBuffer{data, size}, std::istream{static_cast<std::streambuf*>(this)} {}
+
 bool DateUtil::timePointValid(SystemTime time_point) {
   return std::chrono::duration_cast<std::chrono::milliseconds>(time_point.time_since_epoch())
              .count() != 0;

source/common/common/utility.h

@@ -64,6 +64,26 @@ class ProdMonotonicTimeSource : public MonotonicTimeSource {
   static ProdMonotonicTimeSource instance_;
 };
 
+/**
+ * Class used for creating non-copying std::istream's. See InputConstMemoryStream below.
+ */
+class ConstMemoryStreamBuffer : public std::streambuf {
+public:
+  ConstMemoryStreamBuffer(const char* data, size_t size);
+};
+
+/**
+ * std::istream class similar to std::istringstream, except that it provides a view into a region of
+ * constant memory. It can be more efficient than std::istringstream because it doesn't copy the
+ * provided string.
+ *
+ * See https://stackoverflow.com/a/13059195/4447365.
+ */
+class InputConstMemoryStream : public virtual ConstMemoryStreamBuffer, public std::istream {
+public:
+  InputConstMemoryStream(const char* data, size_t size);
+};
+
 /**
  * Utility class for date/time helpers.
  */

source/common/http/header_map_impl.cc

@@ -399,6 +399,29 @@ void HeaderMapImpl::iterateReverse(ConstIterateCb cb, void* context) const {
   }
 }
 
+HeaderMap::Lookup HeaderMapImpl::lookup(const LowerCaseString& key,
+                                        const HeaderEntry** entry) const {
+  StaticLookupEntry::EntryCb cb = ConstSingleton<StaticLookupTable>::get().find(key.get().c_str());
+  if (cb) {
+    // The accessor callbacks for predefined inline headers take a HeaderMapImpl& as an argument;
+    // even though we don't make any modifications, we need to cast_cast in order to use the
+    // accessor.
+    //
+    // Making this work without const_cast would require managing an additional const accessor
+    // callback for each predefined inline header and add to the complexity of the code.
+    StaticLookupResponse ref_lookup_response = cb(const_cast<HeaderMapImpl&>(*this));
+    *entry = *ref_lookup_response.entry_;
+    if (*entry) {
+      return Lookup::Found;
+    } else {
+      return Lookup::NotFound;
+    }
+  } else {
+    *entry = nullptr;
+    return Lookup::NotSupported;
+  }
+}
+
 void HeaderMapImpl::remove(const LowerCaseString& key) {
   StaticLookupEntry::EntryCb cb = ConstSingleton<StaticLookupTable>::get().find(key.get().c_str());
   if (cb) {

source/common/http/header_map_impl.h

@@ -64,6 +64,7 @@ class HeaderMapImpl : public HeaderMap {
   const HeaderEntry* get(const LowerCaseString& key) const override;
   void iterate(ConstIterateCb cb, void* context) const override;
   void iterateReverse(ConstIterateCb cb, void* context) const override;
+  Lookup lookup(const LowerCaseString& key, const HeaderEntry** entry) const override;
   void remove(const LowerCaseString& key) override;
   size_t size() const override { return headers_.size(); }
 

source/common/tracing/BUILD

@@ -12,17 +12,21 @@ envoy_cc_library(
     name = "http_tracer_lib",
     srcs = [
         "http_tracer_impl.cc",
+        "opentracing_driver_impl.cc",
     ],
     hdrs = [
         "http_tracer_impl.h",
+        "opentracing_driver_impl.h",
     ],
+    external_deps = ["opentracing"],
     deps = [
         "//include/envoy/local_info:local_info_interface",
         "//include/envoy/runtime:runtime_interface",
         "//include/envoy/thread_local:thread_local_interface",
         "//include/envoy/tracing:http_tracer_interface",
         "//include/envoy/upstream:cluster_manager_interface",
         "//source/common/access_log:access_log_formatter_lib",
+        "//source/common/buffer:zero_copy_input_stream_lib",
         "//source/common/common:base64_lib",
         "//source/common/common:macros",
         "//source/common/common:utility_lib",