ngx-otel module doesn't compile on Alpine 3.21

[vndroid]

Describe the bug

It can't be compiled on Alpine 3.21.

To reproduce

Steps to reproduce the behavior:

1. Base the official docker file Dockerfile,But base image change to Alpine 3.21.
2. Error log

make[1]: Leaving directory '/tmp/tmp.KOJnkk/pkg-oss-f43e929dc7a6111ef5d9ecb281a75749f7934261/alpine/abuild-module-otel/src/abseil-cpp-20211102.0/build'
CMake Deprecation Warning at CMakeLists.txt:25 (cmake_minimum_required):
Compatibility with CMake < 3.10 will be removed from a future version of
CMake.

Update the VERSION argument <min> value.  Or, use the <min>...<max> syntax
to tell CMake that the project requires at least <min> but has been updated
to work with policies introduced by <max> or earlier.


-- The C compiler identification is GNU 14.2.0
-- The CXX compiler identification is GNU 14.2.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/gcc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/g++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE
-- Found c-ares: /usr/lib/cmake/c-ares/c-ares-config.cmake (found suitable version "1.34.3", minimum required is "1.13.0")
-- Found ZLIB: /usr/lib/libz.so (found version "1.3.1")
-- Found RE2 via CMake.
-- Found OpenSSL: /usr/lib/libcrypto.so (found version "3.3.2")
-- Configuring done (2.0s)
CMake Error at /usr/lib/cmake/re2/re2Targets.cmake:70 (set_target_properties):
The link interface of target "re2::re2" contains:

  absl::absl_check

but the target was not found.  Possible reasons include:

  * There is a typo in the target name.
  * A find_package call is missing for an IMPORTED target.
  * An ALIAS target is missing.

Call Stack (most recent call first):
/usr/lib/cmake/re2/re2Config.cmake:60 (include)
cmake/modules/Findre2.cmake:15 (find_package)
cmake/re2.cmake:48 (find_package)
CMakeLists.txt:318 (include)


-- Generating done (1.0s)
CMake Warning:
Manually-specified variables were not used by the project:

  CMAKE_INSTALL_LIBDIR
  CMAKE_POLICY_DEFAULT_CMP0063


CMake Generate step failed.  Build files cannot be regenerated correctly.
>>> ERROR: nginx-module-otel: build failed
Command exited with non-zero status 1
real 1732.31
user 1377.06
sys 296.44
make: *** [Makefile:189: module-otel] Error 1

Expected behavior

Build Pass.

Your environment

/ # cmake --version
+ cmake --version
cmake version 3.31.1

CMake suite maintained and supported by Kitware (kitware.com/cmake).
/ # cat /etc/alpine-release 
+ cat /etc/alpine-release
3.21.2

Additional context

None

[ston1th]

@vndroid I managed to compile with the latest alpine version using the info from #16 (comment)

I made a few changes, here are the files:

Dockerfile:

FROM docker.io/library/alpine:3.21.2 as otel-module-builder
# Build nginx OpenTelemetry module
# https://github.com/nginxinc/nginx-otel
WORKDIR /opt

RUN apk add \
    cmake build-base openssl-dev zlib-dev pcre-dev \
    pkgconfig c-ares-dev re2-dev \
    grpc-dev protobuf-dev \
    git unzip

RUN wget https://github.com/nginx/nginx/archive/refs/tags/release-1.27.3.zip; unzip release-1.27.3.zip; mv nginx-release-1.27.3 nginx
WORKDIR /opt/nginx
RUN auto/configure --with-compat

WORKDIR /opt
RUN wget https://github.com/nginxinc/nginx-otel/archive/refs/heads/main.zip; unzip main.zip
# Modified CMake config to skip compiling grpc and protobuf, fix opentelemetry build, as well as disable cmake <3.24 workaround
COPY configs/nginx-otel-CMakeLists.txt /opt/nginx-otel-main/CMakeLists.txt
WORKDIR /opt/nginx-otel-main/build
RUN cmake -DNGX_OTEL_NGINX_BUILD_DIR=/opt/nginx/objs ..
RUN make -j 8

nginx-otel-CMakeLists.txt:

cmake_minimum_required(VERSION 3.24.0)
project(nginx-otel)

set(NGX_OTEL_NGINX_BUILD_DIR ""
    CACHE PATH "Nginx build (objs) dir")
set(NGX_OTEL_NGINX_DIR "${NGX_OTEL_NGINX_BUILD_DIR}/.."
    CACHE PATH "Nginx source dir")

set(NGX_OTEL_FETCH_DEPS ON CACHE BOOL "Download dependencies")
set(NGX_OTEL_PROTO_DIR  "" CACHE PATH "OTel proto files root")

if(NOT CMAKE_BUILD_TYPE)
    set(CMAKE_BUILD_TYPE RelWithDebInfo)
endif()

set(CMAKE_CXX_VISIBILITY_PRESET hidden)

include(FetchContent)

FetchContent_Declare(
    otelcpp
    GIT_REPOSITORY https://github.com/open-telemetry/opentelemetry-cpp
    GIT_TAG        955a807c0461544560429c2414b8967f6023e590 # v1.18.0
    GIT_SUBMODULES third_party/opentelemetry-proto
    GIT_SHALLOW    ON)

set(BUILD_TESTING OFF CACHE INTERNAL "")
set(WITH_EXAMPLES OFF CACHE INTERNAL "")
set(WITH_ABSEIL ON CACHE INTERNAL "")

set(CMAKE_POSITION_INDEPENDENT_CODE ON)
set(CMAKE_POLICY_DEFAULT_CMP0063 NEW)

FetchContent_MakeAvailable(otelcpp)

set_property(DIRECTORY ${otelcpp_SOURCE_DIR}
             PROPERTY EXCLUDE_FROM_ALL YES)

if(NOT NGX_OTEL_PROTO_DIR)
    set(NGX_OTEL_PROTO_DIR
        "${otelcpp_SOURCE_DIR}/third_party/opentelemetry-proto")
endif()

add_library(opentelemetry-cpp::trace ALIAS opentelemetry_trace)

find_package(Protobuf REQUIRED)
find_package(gRPC REQUIRED)

set(PROTO_DIR ${NGX_OTEL_PROTO_DIR})
set(PROTOS
    "${PROTO_DIR}/opentelemetry/proto/common/v1/common.proto"
    "${PROTO_DIR}/opentelemetry/proto/resource/v1/resource.proto"
    "${PROTO_DIR}/opentelemetry/proto/trace/v1/trace.proto"
    "${PROTO_DIR}/opentelemetry/proto/collector/trace/v1/trace_service.proto")

set(PROTO_OUT_DIR "${CMAKE_CURRENT_BINARY_DIR}")
set(PROTO_SOURCES
    "${PROTO_OUT_DIR}/opentelemetry/proto/common/v1/common.pb.cc"
    "${PROTO_OUT_DIR}/opentelemetry/proto/resource/v1/resource.pb.cc"
    "${PROTO_OUT_DIR}/opentelemetry/proto/trace/v1/trace.pb.cc"
    "${PROTO_OUT_DIR}/opentelemetry/proto/collector/trace/v1/trace_service.pb.cc"
    "${PROTO_OUT_DIR}/opentelemetry/proto/collector/trace/v1/trace_service.grpc.pb.cc")

# generate protobuf code for lite runtime
add_custom_command(
    OUTPUT ${PROTO_SOURCES}
    COMMAND protobuf::protoc
        --proto_path ${PROTO_DIR}
        --cpp_out lite:${PROTO_OUT_DIR}
        --grpc_out ${PROTO_OUT_DIR}
        --plugin protoc-gen-grpc=$<TARGET_FILE:gRPC::grpc_cpp_plugin>
        ${PROTOS}
    # remove inconsequential UTF8 check during serialization to aid performance
    COMMAND sed -i.bak -E
        -e [[/    ::(PROTOBUF_NAMESPACE_ID|google::protobuf)::internal::WireFormatLite::VerifyUtf8String\(/,/\);/d]]
        ${PROTO_SOURCES}
    DEPENDS ${PROTOS} protobuf::protoc gRPC::grpc_cpp_plugin
    VERBATIM)

add_library(ngx_otel_module MODULE
    src/http_module.cpp
    src/grpc_log.cpp
    src/modules.c
    ${PROTO_SOURCES})

# avoid 'lib' prefix in binary name
set_target_properties(ngx_otel_module PROPERTIES PREFIX "")

target_include_directories(ngx_otel_module PRIVATE
    ${NGX_OTEL_NGINX_BUILD_DIR}
    ${NGX_OTEL_NGINX_DIR}/src/core
    ${NGX_OTEL_NGINX_DIR}/src/event
    ${NGX_OTEL_NGINX_DIR}/src/event/modules
    ${NGX_OTEL_NGINX_DIR}/src/event/quic
    ${NGX_OTEL_NGINX_DIR}/src/os/unix
    ${NGX_OTEL_NGINX_DIR}/src/http
    ${NGX_OTEL_NGINX_DIR}/src/http/modules
    ${NGX_OTEL_NGINX_DIR}/src/http/v2
    ${NGX_OTEL_NGINX_DIR}/src/http/v3
    ${PROTO_OUT_DIR})

target_link_libraries(ngx_otel_module
    absl::log_initialize
    opentelemetry-cpp::trace
    gRPC::grpc++)

The inclusion of absl::log_initialize in the target_link_libraries is needed. Otherwise the linker won't find the lib:

Error relocating ngx_otel_module.so: _ZN4absl12lts_2024072213InitializeLogEv: symbol not found

You will need to add the grpc-cpp and abseil-cpp-log-initialize dependencies to your final container: apk add --no-cache grpc-cpp abseil-cpp-log-initialize

[thresheek]

This particular issue is fixed for nginx-otel on Alpine 3.21 via nginx/pkg-oss@b9dbbfb - the fix will be available when nginx 1.27.4 is released.