chore: Switch cloud-collector and k8s-collector to Rust mains (#429)

Generalize cmake infra for building Rust binaries.

This also causes compiler include paths to shift, which produces header conflicts.
Include absolute paths in generated code.

(cherry picked from commit 9b22fd7)

Author: yonch

Cargo.lock

@@ -2,6 +2,10 @@
 members = [
   "crates/kernel-collector-sys",
   "crates/kernel-collector-bin",
+  "crates/cloud-collector-sys",
+  "crates/cloud-collector-bin",
+  "crates/k8s-relay-sys",
+  "crates/k8s-relay-bin",
   "crates/perfect_hash_map",
   "crates/render_parser",
 ]

Cargo.toml

@@ -12,15 +12,22 @@ endif()
 if(NOT DEFINED RUST_BIN_TARGET_DIR)
   message(FATAL_ERROR "RUST_BIN_TARGET_DIR not provided to cargo_build_rust.cmake")
 endif()
+if(NOT DEFINED RUST_PACKAGE)
+  message(FATAL_ERROR "RUST_PACKAGE not provided to cargo_build_rust.cmake")
+endif()
 
-# Read the CMake-generated link command for the kernel-collector C++ target
+# Read the CMake-generated link command for the dummy/existing C++ target
 file(READ "${LINK_FILE}" LINK_CONTENT)
 get_filename_component(LINK_DIR "${LINK_FILE}" DIRECTORY)
+# Derive the target binary directory (two levels up from CMakeFiles/<target>.dir)
+get_filename_component(_cmakefiles_dir "${LINK_DIR}" DIRECTORY)
+get_filename_component(TARGET_BIN_DIR "${_cmakefiles_dir}" DIRECTORY)
 
 # Seed library search paths with known build output dirs and system dirs
 set(SEARCH_DIRS
   "${BIN_DIR}/collector/kernel"
   "${BIN_DIR}/collector"
+  "${TARGET_BIN_DIR}"
   "${BIN_DIR}/render"
   "${BIN_DIR}/channel"
   "${BIN_DIR}/config"
@@ -115,7 +122,7 @@ execute_process(
     OTN_LINK_SEARCH=${OTN_LINK_SEARCH}
     OTN_LINK_LIBS=${OTN_LINK_LIBS_ESC}
     OTN_LINK_ARGS=${OTN_LINK_ARGS_ESC}
-    cargo build --release --package kernel-collector-bin --manifest-path ${PROJ_DIR}/Cargo.toml
+    cargo build --release --package ${RUST_PACKAGE} --manifest-path ${PROJ_DIR}/Cargo.toml
   WORKING_DIRECTORY ${PROJ_DIR}
   RESULT_VARIABLE CARGO_RES
   OUTPUT_VARIABLE CARGO_OUT

collector/kernel/cargo_build_rust.cmake cmake/cargo_build_rust.cmakecollector/kernel/cargo_build_rust.cmake renamed to cmake/cargo_build_rust.cmake

@@ -82,7 +82,10 @@ function(build_go_package NAME MODULE)
   get_target_property(MOD_BUILD_DIR "${MODULE}" MOD_BUILD_DIR)
   get_target_property(GO_MOD_FILE "${MODULE}" GO_MOD_FILE)
   set(BUILD_DIR "${MOD_BUILD_DIR}/${NAME}")
-  set(OUT_BINARY "${CMAKE_CURRENT_BINARY_DIR}/${NAME}")
+  # Place Go binaries under a dedicated bin/ directory to avoid
+  # colliding with CMake's phony target paths when the target name
+  # matches the binary name (required by Ninja generator).
+  set(OUT_BINARY "${CMAKE_CURRENT_BINARY_DIR}/bin/${NAME}")
 
   set(TARGET_OPTIONS)
   if(ARG_ALL)
@@ -126,6 +129,9 @@ function(build_go_package NAME MODULE)
       TARGET
         "${TARGET}"
       POST_BUILD
+      COMMAND
+        ${CMAKE_COMMAND} -E make_directory
+          "${CMAKE_CURRENT_BINARY_DIR}/bin"
       WORKING_DIRECTORY
         "${BUILD_DIR}"
       BYPRODUCTS

cmake/golang.cmake

@@ -0,0 +1,86 @@
+include_guard()
+
+function(add_rust_main)
+  cmake_parse_arguments(ARG "" "TARGET;STRIPPED_TARGET;PACKAGE;BIN_NAME;PROJ_DIR;RUST_BIN_TARGET_DIR;DUMMY_TARGET" "LINK_LIBS" ${ARGN})
+
+  if(NOT DEFINED ARG_TARGET)
+    message(FATAL_ERROR "add_rust_main: TARGET is required")
+  endif()
+  if(NOT DEFINED ARG_STRIPPED_TARGET)
+    message(FATAL_ERROR "add_rust_main: STRIPPED_TARGET is required")
+  endif()
+  if(NOT DEFINED ARG_PACKAGE)
+    message(FATAL_ERROR "add_rust_main: PACKAGE is required (Cargo package)")
+  endif()
+  if(NOT DEFINED ARG_BIN_NAME)
+    message(FATAL_ERROR "add_rust_main: BIN_NAME is required (expected executable name)")
+  endif()
+  if(NOT ARG_LINK_LIBS)
+    message(FATAL_ERROR "add_rust_main: LINK_LIBS is required (C++ link libraries)")
+  endif()
+
+  if(NOT DEFINED ARG_PROJ_DIR)
+    set(ARG_PROJ_DIR "${PROJECT_SOURCE_DIR}")
+  endif()
+  if(NOT DEFINED ARG_RUST_BIN_TARGET_DIR)
+    set(ARG_RUST_BIN_TARGET_DIR "${CMAKE_BINARY_DIR}/target")
+  endif()
+  if(NOT DEFINED ARG_DUMMY_TARGET)
+    set(ARG_DUMMY_TARGET "${ARG_TARGET}-dummy")
+  endif()
+
+  # 1) Create a tiny dummy main to force generation of a link.txt for the link line
+  set(_dummy_main "${CMAKE_CURRENT_BINARY_DIR}/${ARG_DUMMY_TARGET}_main.cc")
+  file(WRITE "${_dummy_main}" "int main(int, char**) { return 0; }\n")
+
+  add_executable(${ARG_DUMMY_TARGET} "${_dummy_main}")
+  target_link_libraries(
+    ${ARG_DUMMY_TARGET}
+    PUBLIC
+      ${ARG_LINK_LIBS}
+      static-executable
+  )
+
+  # Path to dummy's link.txt produced by the generator
+  set(_link_file "${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/${ARG_DUMMY_TARGET}.dir/link.txt")
+
+  # 2) Build the Rust binary via cargo using link hints from the dummy
+  set(_rust_bin_path "${ARG_RUST_BIN_TARGET_DIR}/release/${ARG_BIN_NAME}")
+
+  add_custom_command(
+    OUTPUT "${_rust_bin_path}"
+    COMMAND ${CMAKE_COMMAND}
+      -DLINK_FILE=${_link_file}
+      -DBIN_DIR=${CMAKE_BINARY_DIR}
+      -DPROJ_DIR=${ARG_PROJ_DIR}
+      -DRUST_BIN_TARGET_DIR=${ARG_RUST_BIN_TARGET_DIR}
+      -DRUST_PACKAGE=${ARG_PACKAGE}
+      -P ${CMAKE_SOURCE_DIR}/cmake/cargo_build_rust.cmake
+    WORKING_DIRECTORY ${ARG_PROJ_DIR}
+    DEPENDS ${ARG_LINK_LIBS}
+    VERBATIM
+  )
+
+  add_custom_target(
+    ${ARG_TARGET}
+    DEPENDS "${_rust_bin_path}"
+  )
+
+  # 3) Stripped variant
+  add_custom_command(
+    OUTPUT ${_rust_bin_path}-stripped
+    COMMAND ${CMAKE_SOURCE_DIR}/dev/strip-symbols.sh ${_rust_bin_path}
+    DEPENDS ${_rust_bin_path}
+    VERBATIM
+  )
+  add_custom_target(
+    ${ARG_STRIPPED_TARGET}
+    DEPENDS "${_rust_bin_path}-stripped"
+  )
+  set_property(
+    TARGET ${ARG_STRIPPED_TARGET}
+    PROPERTY
+      "OUTPUT" "${_rust_bin_path}-stripped"
+  )
+
+endfunction()

cmake/rust_main.cmake

@@ -1,30 +1,30 @@
 # Copyright The OpenTelemetry Authors
 # SPDX-License-Identifier: Apache-2.0
 
-add_executable(
-  cloud-collector
-    main.cc
+add_library(
+  cloud_agentlib
+  STATIC
+    entrypoint.cc
     collector.cc
     enumerator.cc
     ingest_connection.cc
 )
-harden_executable(cloud-collector)
-
-add_dependencies(collectors cloud-collector)
-
-target_compile_options(
-  cloud-collector
+target_include_directories(
+  cloud_agentlib
   PRIVATE
-    ${CXX_ERROR_LIMIT_FLAG}=1
+    ${PROJECT_SOURCE_DIR}
+    ${CMAKE_CURRENT_BINARY_DIR}
 )
-
 target_link_libraries(
-  cloud-collector
+  cloud_agentlib
   PUBLIC
+    signal_handler 
+)
+
+set(CLOUD_COLLECTOR_LINK_LIBRARIES
+    cloud_agentlib
     render_ebpf_net_cloud_collector
     render_ebpf_net_ingest_writer
-    render_rust_ebpf_net
-    signal_handler
     aws-sdk-cpp
     reconnecting_channel
     connection_caretaker
@@ -38,40 +38,33 @@ target_link_libraries(
     aws_instance_metadata
     spdlog
     static-executable
-    "-Wl,--no-as-needed"
     protobuf::libprotobuf
     ZLIB::ZLIB
     versions
-    "-Wl,--as-needed"
-)
-
-set_target_properties(
-  cloud-collector
-  PROPERTIES LINK_FLAGS "-pthread"
 )
 
-strip_binary(cloud-collector)
-
-install(
-  TARGETS
-    cloud-collector
-  RUNTIME
-  DESTINATION ${CMAKE_INSTALL_BINOIR}
-  COMPONENT cloud-collector
-)
 
 lint_shell_script_bundle(
   cloud-collector-scripts
   SOURCES
     entrypoint.sh
 )
 
+include(rust_main)
+add_rust_main(
+  TARGET           cloud-collector
+  STRIPPED_TARGET  cloud-collector-stripped
+  PACKAGE          cloud-collector-bin
+  BIN_NAME         cloud-collector
+  LINK_LIBS        ${CLOUD_COLLECTOR_LINK_LIBRARIES}
+)
+
+add_dependencies(collectors cloud-collector)
+
 if("${CMAKE_BUILD_TYPE}" STREQUAL "Debug")
   build_custom_docker_image(
     cloud-collector
     OUT_DIR srv
-    ARTIFACTS_OF
-      cloud-collector
     OUTPUT_OF
       cloud-collector-scripts
       cloud-collector-stripped

collector/cloud/CMakeLists.txt

@@ -36,7 +36,7 @@
  * environment variables `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY`.
  */
 
-int main(int argc, char *argv[])
+static int cloud_collector_run(int argc, char **argv)
 {
   ::uv_loop_t loop;
   if (auto const error = ::uv_loop_init(&loop)) {
@@ -120,3 +120,9 @@ int main(int argc, char *argv[])
 
   return EXIT_SUCCESS;
 }
+
+extern "C" int otn_cloud_collector_main(int argc, const char **argv)
+{
+  return cloud_collector_run(argc, const_cast<char **>(argv));
+}
+