Use a simple header for embedding tracer version. (#105)

BUILD.bazel

@@ -21,9 +21,9 @@ cc_library(
         "src/tracer_options.h",
         "src/writer.cpp",
         "src/writer.h",
-        ":version_number.h",
     ],
     hdrs = [
+        "include/datadog/version.h",
         "include/datadog/opentracing.h",
         "include/datadog/tags.h",
     ],
@@ -45,26 +45,6 @@ cc_library(
     ],
 )
 
-genrule(
-    name = "generate_version_number_h",
-    srcs = glob([
-        "CMakeLists.txt",
-        "src/*",
-    ]),
-    outs = [
-        "version_number.h",
-    ],
-    cmd = """
-    TEMP_DIR=$$(mktemp -d)
-    trap -- 'rm -r $$TEMP_DIR' EXIT
-    VERSION_NUMBER_H_OUT=$${PWD}/$(location :version_number.h)
-    CMAKE_ROOT=$$(dirname $${PWD}/$(location :CMakeLists.txt))
-    cd $$TEMP_DIR
-    cmake -DHEADERS_ONLY=ON -L $$CMAKE_ROOT
-    mv version_number.h $$VERSION_NUMBER_H_OUT
-    """,
-)
-
 cc_library(
     name = "3rd_party_nlohmann",
     hdrs = ["3rd_party/include/nlohmann/json.hpp"],

CMakeLists.txt

@@ -14,7 +14,6 @@ option(BUILD_SHARED "Builds shared library" ON)
 option(BUILD_STATIC "Builds static library" OFF)
 option(BUILD_PLUGIN "Builds plugin (requires gcc and not macos)" OFF)
 option(BUILD_TESTING "Builds tests, also enables BUILD_SHARED" OFF)
-option(HEADERS_ONLY "Only generate version_number.h" OFF)
 
 if(BUILD_TESTING)
   set(BUILD_SHARED ON)
@@ -23,37 +22,6 @@ endif()
 # Configure the compiler.
 set(CMAKE_CXX_STANDARD 14)
 
-# If a git tag is set then use that as the version number,
-# otherwise use short commit hash. If git unavailable,
-# "unknown" is used.
-if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/.git)
-  find_package(Git)
-  if(GIT_FOUND)
-    execute_process(
-      COMMAND ${GIT_EXECUTABLE} describe --tags --always
-      WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
-      OUTPUT_VARIABLE "VERSION"
-      ERROR_QUIET
-      OUTPUT_STRIP_TRAILING_WHITESPACE)
-    message(STATUS "Git version: ${VERSION}")
-  else(GIT_FOUND)
-    set(VERSION "unknown")
-    message(WARNING "Git missing, version number for this build is 'unknown'")
-  endif(GIT_FOUND)
-else(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/.git)
-  set(VERSION "unknown")
-  message(WARNING "Not being built from git repo, version number for this build is 'unknown'")
-endif(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/.git)
-
-configure_file(
-  "${PROJECT_SOURCE_DIR}/src/version_number.h.in"
-  "${PROJECT_BINARY_DIR}/version_number.h")
-include_directories("${PROJECT_BINARY_DIR}")
-
-if(HEADERS_ONLY)
-  return()
-endif()
-
 # Dependencies
 find_path(OPENTRACING_INCLUDE_DIR NAMES opentracing/tracer.h)
 find_library(OPENTRACING_LIB opentracing)

include/datadog/version.h

@@ -0,0 +1,15 @@
+#ifndef DD_INCLUDE_VERSION_H
+#define DD_INCLUDE_VERSION_H
+
+#include <string>
+
+namespace datadog {
+namespace version {
+
+const std::string tracer_version = "v1.0.0";
+const std::string cpp_version = std::to_string(__cplusplus);
+
+}  // namespace version
+}  // namespace datadog
+
+#endif  // DD_INCLUDE_VERSION_H

src/agent_writer.cpp

@@ -4,7 +4,6 @@
 #include "sample.h"
 #include "span.h"
 #include "transport.h"
-#include "version_number.h"
 
 namespace datadog {
 namespace opentracing {

src/encoder.cpp

@@ -1,8 +1,8 @@
 #include "encoder.h"
+#include <datadog/version.h>
 #include <nlohmann/json.hpp>
 #include "sample.h"
 #include "span.h"
-#include "version_number.h"
 
 using json = nlohmann::json;
 
@@ -26,8 +26,8 @@ AgentHttpEncoder::AgentHttpEncoder(std::shared_ptr<SampleProvider> sampler)
   // Set up common headers and default encoder
   common_headers_ = {{header_content_type, "application/msgpack"},
                      {header_dd_meta_lang, "cpp"},
-                     {header_dd_meta_lang_version, config::cpp_version},
-                     {header_dd_meta_tracer_version, config::tracer_version}};
+                     {header_dd_meta_lang_version, ::datadog::version::cpp_version},
+                     {header_dd_meta_tracer_version, ::datadog::version::tracer_version}};
 }
 
 const std::string agent_api_path = "/v0.4/traces";

src/writer.cpp

@@ -2,7 +2,6 @@
 #include <iostream>
 #include "encoder.h"
 #include "span.h"
-#include "version_number.h"
 
 namespace datadog {
 namespace opentracing {

test/agent_writer_test.cpp

@@ -1,7 +1,7 @@
 #include "../src/agent_writer.h"
+#include <datadog/version.h>
 #include "../src/agent_writer.cpp"  // Otherwise the compiler won't generate AgentWriter for us.
 #include "mocks.h"
-#include "version_number.h"
 
 #include <ctime>
 
@@ -67,12 +67,13 @@ TEST_CASE("writer") {
                                    {CURLOPT_URL, "http://hostname:6319/v0.4/traces"},
                                    {CURLOPT_TIMEOUT_MS, "2000"},
                                    {CURLOPT_POSTFIELDSIZE, "135"}});
-    REQUIRE(handle->headers == std::map<std::string, std::string>{
-                                   {"Content-Type", "application/msgpack"},
-                                   {"Datadog-Meta-Lang", "cpp"},
-                                   {"Datadog-Meta-Tracer-Version", config::tracer_version},
-                                   {"Datadog-Meta-Lang-Version", config::cpp_version},
-                                   {"X-Datadog-Trace-Count", "1"}});
+    REQUIRE(handle->headers ==
+            std::map<std::string, std::string>{
+                {"Content-Type", "application/msgpack"},
+                {"Datadog-Meta-Lang", "cpp"},
+                {"Datadog-Meta-Tracer-Version", ::datadog::version::tracer_version},
+                {"Datadog-Meta-Lang-Version", ::datadog::version::cpp_version},
+                {"X-Datadog-Trace-Count", "1"}});
   }
 
   SECTION("responses are sent to sampler") {
@@ -324,12 +325,13 @@ TEST_CASE("writer") {
       writer.write(make_trace(
           {TestSpanData{"web", "service", "resource", "service.name", 3, 1, 1, 69, 420, 0}}));
       writer.flush(std::chrono::seconds(10));
-      REQUIRE(handle->headers == std::map<std::string, std::string>{
-                                     {"Content-Type", "application/msgpack"},
-                                     {"Datadog-Meta-Lang", "cpp"},
-                                     {"Datadog-Meta-Tracer-Version", config::tracer_version},
-                                     {"Datadog-Meta-Lang-Version", config::cpp_version},
-                                     {"X-Datadog-Trace-Count", "3"}});
+      REQUIRE(handle->headers ==
+              std::map<std::string, std::string>{
+                  {"Content-Type", "application/msgpack"},
+                  {"Datadog-Meta-Lang", "cpp"},
+                  {"Datadog-Meta-Tracer-Version", ::datadog::version::tracer_version},
+                  {"Datadog-Meta-Lang-Version", ::datadog::version::cpp_version},
+                  {"X-Datadog-Trace-Count", "3"}});
     }
   }
 }