Remove protobuf depenency

Original motivation for this change was to
remove unnecessary binary dependency on
libatomic. As it appeared source of this dependency
was protobuf. As this quite complex piece of
software was used only to generate simple json
I swiched it to boost::json.
I decided to use boost::json because boost already was
dependency for eBPF discovery.

CMakeLists.txt

@@ -126,7 +126,6 @@ list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/third_party/libbpf-boo
 
 add_subdirectory(third_party)
 add_subdirectory(libebpfdiscovery)
-add_subdirectory(libebpfdiscoveryproto)
 add_subdirectory(libebpfdiscoveryshared)
 add_subdirectory(libebpfdiscoveryskel)
 add_subdirectory(libhttpparser)

conanfile.txt

@@ -1,5 +1,4 @@
 [requires]
-protobuf/3.21.9
 ms-gsl/4.0.0
 fmt/10.1.1
 spdlog/1.12.0

ebpfdiscoverysrv/CMakeLists.txt

@@ -20,3 +20,7 @@ add_executable(${TARGET} ${SOURCES})
 target_link_libraries(${TARGET} PRIVATE ebpfdiscovery)
 target_link_options(${TARGET} PRIVATE "-static-libgcc" "-static-libstdc++")
 target_compile_definitions(${TARGET} PUBLIC PROJECT_VERSION="${PROJECT_VERSION}")
+
+if (BUILD_TESTS)
+	add_test(NAME binary_dependencies COMMAND bash ${TESTS_ROOT_DIR}/binary_dependencies.sh $<TARGET_FILE:${TARGET}>)
+endif ()

ebpfdiscoverysrv/test/dependencies.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+binary_path="${1}"
+approved_binary_dependencies=("libelf|libz|libm|libdl|librt|libpthread|libc|ld-linux")
+
+depenencies=$(objdump -p "${binary_path}" 2>/dev/null | grep NEEDED | grep -Ev "${approved_binary_dependencies}")
+
+if [ ! -z "${depenencies}" ]; then
+  echo "Additional dependencies: ${depenencies}"
+  exit 1
+fi

libebpfdiscovery/CMakeLists.txt

@@ -29,7 +29,6 @@ target_include_directories(${TARGET} PRIVATE src PUBLIC headers)
 target_link_libraries(${TARGET}
         PUBLIC
             libpf-tools
-            ebpfdiscoveryproto
             ebpfdiscoveryshared
             ebpfdiscoveryskel
             httpparser

libebpfdiscoveryproto/headers/ebpfdiscoveryproto/Translator.h → libebpfdiscovery/headers/ebpfdiscovery/Json.h

@@ -1,30 +1,35 @@
-/*
- * Copyright 2023 Dynatrace LLC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#pragma once
-
-#include "ebpfdiscoveryproto/service.pb.h"
-#include "service/Service.h"
-
-#include <vector>
-
-namespace proto {
-
-ServicesList internalToProto(const std::vector<std::reference_wrapper<service::Service>>& services);
-
-std::string protoToJson(const ServicesList& protoServices);
-
-} // namespace proto
+/*
+ * Copyright 2023 Dynatrace LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <boost/json.hpp>
+#include <boost/describe.hpp>
+#include <string_view>
+
+namespace boost::json {
+	  template<typename T>
+    void tag_invoke(json::value_from_tag, json::value& v, std::reference_wrapper<T> const& wrapped) {
+        v = json::value_from(wrapped.get());
+    }
+} // namespace boost::json
+
+template<typename T>
+boost::json::object toJson(std::string_view key, T convertibleValue) {
+	boost::json::object outJson{};
+	outJson[key] = boost::json::value_from(convertibleValue);
+	return outJson; 
+}

libebpfdiscovery/src/Discovery.cpp

@@ -17,7 +17,7 @@
 #include "ebpfdiscovery/Discovery.h"
 
 #include "ebpfdiscovery/Session.h"
-#include "ebpfdiscoveryproto/Translator.h"
+#include "ebpfdiscovery/Json.h"
 #include "logging/Logger.h"
 #include "service/IpAddress.h"
 
@@ -32,6 +32,7 @@
 #include <string>
 #include <string_view>
 #include <thread>
+#include <iostream>
 
 namespace ebpfdiscovery {
 
@@ -62,9 +63,8 @@ void Discovery::outputServicesToStdout() {
 		return;
 	}
 
-	const auto servicesProto{proto::internalToProto(services)};
-	const auto servicesJson{proto::protoToJson(servicesProto)};
-	std::cout << servicesJson << std::endl;
+
+	std::cout << toJson("services",services) << std::endl;
 	serviceAggregator.clear();
 }
 

libebpfdiscoveryproto/test/TranslatorTest.cpp → libebpfdiscovery/test/JsonTest.cpp

@@ -14,15 +14,16 @@
  * limitations under the License.
  */
 
-#include "ebpfdiscoveryproto/Translator.h"
-
+#include "ebpfdiscovery/Json.h"
 #include <gtest/gtest.h>
 
-using namespace proto;
+#include <iostream>
+#include <string>
+#include <vector>
 
-class ProtobufTranslatorTest : public testing::Test {};
+class Json : public testing::Test {};
 
-TEST_F(ProtobufTranslatorTest, successfulTranslationToJson) {
+TEST_F(Json, servicesToJson) {
 
 	std::vector<std::reference_wrapper<service::Service>> internalServices;
 	service::Service service1{.pid = 1, .endpoint = "/endpoint/1", .internalClientsNumber = 1, .externalClientsNumber = 2};
@@ -38,13 +39,17 @@ TEST_F(ProtobufTranslatorTest, successfulTranslationToJson) {
 	internalServices.push_back(service4);
 	internalServices.push_back(service5);
 
-	const auto proto{internalToProto(internalServices)};
-	const auto result{protoToJson(proto)};
+	boost::json::object outJson{};
+	outJson["service"] = boost::json::value_from(internalServices);
+
+	std::stringstream buffer;
+	buffer << outJson;
+
 	const std::string expected{"{\"service\":[{\"pid\":1,\"endpoint\":\"/endpoint/"
 							   "1\",\"internalClientsNumber\":1,\"externalClientsNumber\":2},{\"pid\":2,\"endpoint\":\"/endpoint/"
 							   "1\",\"internalClientsNumber\":1,\"externalClientsNumber\":2},{\"pid\":3,\"endpoint\":\"/endpoint/"
 							   "2\",\"internalClientsNumber\":1,\"externalClientsNumber\":2},{\"pid\":4,\"endpoint\":\"google.com/"
 							   "endpoint/3\",\"domain\":\"google.com\",\"scheme\":\"http\",\"internalClientsNumber\":1,\"externalClientsNumber\":2},{\"pid\":5,\"endpoint\":\"dynatrace.com/"
 							   "endpoint/4\",\"domain\":\"dynatrace.com\",\"scheme\":\"https\",\"internalClientsNumber\":1,\"externalClientsNumber\":2}]}"};
-	EXPECT_EQ(result, expected);
+	EXPECT_EQ(buffer.str(), expected);
 }

libservice/headers/service/Service.h

@@ -18,6 +18,7 @@
 
 #include <cstdint>
 #include <string>
+#include <boost/describe.hpp>
 
 namespace service {
 
@@ -35,4 +36,6 @@ struct Service {
 	}
 };
 
-} // namespace service
+BOOST_DESCRIBE_STRUCT(Service, (), (pid, endpoint, domain, scheme, internalClientsNumber, externalClientsNumber))
+
+} // namespace service