build: drop submodules

.github/workflows/cmake-ci.yml

@@ -9,32 +9,27 @@ on:
 
 jobs:
   build:
-    name: CMake on ${{ matrix.os }} with ${{ matrix.dependencies }}
+    name: CMake on ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
         os: [macos-14, ubuntu-22.04, windows-2022]
-        dependencies: [submodule, vcpkg]
     steps:
       - name: Checkout source
         uses: actions/checkout@v7
-        with:
-          submodules: ${{ matrix.dependencies == 'submodule' }}
 
       - name: Mount vcpkg cache
-        if: matrix.dependencies == 'vcpkg'
         uses: actions/cache@v5
         with:
           path: "~/.cache/vcpkg/archives"
           key: vcpkg-${{ matrix.os }}
 
       - name: Default to x64-windows vcpkg triplet
-        if: matrix.dependencies == 'vcpkg' && runner.os == 'Windows'
+        if: runner.os == 'Windows'
         run: echo "VCPKG_DEFAULT_TRIPLET=x64-windows" | Out-File -FilePath $Env:GITHUB_ENV -Encoding utf-8 -Append
 
       - name: Install vcpkg dependencies
-        if: matrix.dependencies == 'vcpkg'
         run: vcpkg install benchmark civetweb curl[core] gtest zlib
 
       - name: Generate German locale on Ubuntu
@@ -54,20 +49,12 @@ jobs:
         if: runner.os == 'macOS'
         run: brew install ninja
 
-      - name: "Configure for Unix with internal dependencies"
-        if: matrix.dependencies == 'submodule' && runner.os != 'Windows'
-        run: cmake -DUSE_THIRDPARTY_LIBRARIES=ON -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/_install -DENABLE_WARNINGS_AS_ERRORS=ON -DENABLE_COMPRESSION=OFF -DENABLE_PUSH=OFF -DCMAKE_DEBUG_POSTFIX=_d -DCMAKE_CONFIGURATION_TYPES='Release;Debug' -G"Ninja Multi-Config" -S ${{ github.workspace }} -B ${{ github.workspace }}/_build -DBUILD_SHARED_LIBS=ON
-
-      - name: "Configure for Windows with internal dependencies"
-        if: matrix.dependencies == 'submodule' && runner.os == 'Windows'
-        run: cmake -DUSE_THIRDPARTY_LIBRARIES=ON -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/_install -DENABLE_WARNINGS_AS_ERRORS=ON -DENABLE_COMPRESSION=OFF -DENABLE_PUSH=OFF -DCMAKE_DEBUG_POSTFIX=_d -S ${{ github.workspace }} -B ${{ github.workspace }}/_build  -DBUILD_SHARED_LIBS=ON
-
       - name: "Configure for Unix with vcpkg dependencies"
-        if: matrix.dependencies == 'vcpkg' && runner.os != 'Windows'
+        if: runner.os != 'Windows'
         run: cmake -DUSE_THIRDPARTY_LIBRARIES=OFF -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/_install "-DCMAKE_TOOLCHAIN_FILE=${VCPKG_INSTALLATION_ROOT}/scripts/buildsystems/vcpkg.cmake" -DCMAKE_DEBUG_POSTFIX=_d -DCMAKE_CONFIGURATION_TYPES='Release;Debug' -G"Ninja Multi-Config" -S ${{ github.workspace }} -B ${{ github.workspace }}/_build
 
       - name: "Configure for Windows with vcpkg dependencies"
-        if: matrix.dependencies == 'vcpkg' && runner.os == 'Windows'
+        if: runner.os == 'Windows'
         run: cmake -DUSE_THIRDPARTY_LIBRARIES=OFF -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/_install "-DCMAKE_TOOLCHAIN_FILE=${Env:VCPKG_INSTALLATION_ROOT}\scripts\buildsystems\vcpkg.cmake" -DCMAKE_DEBUG_POSTFIX=_d -S ${{ github.workspace }} -B ${{ github.workspace }}/_build
 
       - name: "Build Debug"
@@ -94,20 +81,12 @@ jobs:
       - name: "Install Release"
         run: cmake --install ${{ github.workspace }}/_build --config Release
 
-      - name: "Configure CMake import for Unix with internal dependencies"
-        if: matrix.dependencies == 'submodule' && runner.os != 'Windows'
-        run: cmake -Dprometheus-cpp_DIR=${{ github.workspace }}/_install/lib/cmake/prometheus-cpp -DCMAKE_CONFIGURATION_TYPES='Release;Debug' -G"Ninja Multi-Config" -S ${{ github.workspace }}/cmake/project-import-cmake -B ${{ github.workspace }}/_import_cmake
-
-      - name: "Configure CMake import for Windows with internal dependencies"
-        if: matrix.dependencies == 'submodule' && runner.os == 'Windows'
-        run: cmake -Dprometheus-cpp_DIR=${{ github.workspace }}/_install/lib/cmake/prometheus-cpp -S ${{ github.workspace }}/cmake/project-import-cmake -B ${{ github.workspace }}/_import_cmake
-
       - name: "Configure CMake import for Unix with vcpkg dependencies"
-        if: matrix.dependencies == 'vcpkg' && runner.os != 'Windows'
+        if: runner.os != 'Windows'
         run: cmake -Dprometheus-cpp_DIR=${{ github.workspace }}/_install/lib/cmake/prometheus-cpp "-DCMAKE_TOOLCHAIN_FILE=${VCPKG_INSTALLATION_ROOT}/scripts/buildsystems/vcpkg.cmake" -DCMAKE_CONFIGURATION_TYPES='Release;Debug' -G"Ninja Multi-Config" -S ${{ github.workspace }}/cmake/project-import-cmake -B ${{ github.workspace }}/_import_cmake
 
       - name: "Configure CMake import for Windows with vcpkg dependencies"
-        if: matrix.dependencies == 'vcpkg' && runner.os == 'Windows'
+        if: runner.os == 'Windows'
         run: cmake -Dprometheus-cpp_DIR=${{ github.workspace }}/_install/lib/cmake/prometheus-cpp "-DCMAKE_TOOLCHAIN_FILE=${Env:VCPKG_INSTALLATION_ROOT}\scripts\buildsystems\vcpkg.cmake" -S ${{ github.workspace }}/cmake/project-import-cmake -B ${{ github.workspace }}/_import_cmake
 
       - name: "Build CMake import Debug"
@@ -117,21 +96,21 @@ jobs:
         run: cmake --build ${{ github.workspace }}/_import_cmake --config Release
 
       - name: "Configure for Unix Shared Libs with internal dependencies"
-        if: matrix.dependencies == 'submodule' && runner.os != 'Windows'
-        run: cmake -DUSE_THIRDPARTY_LIBRARIES=ON -DBUILD_SHARED_LIBS=ON -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/_install_shared -DENABLE_WARNINGS_AS_ERRORS=ON -DENABLE_COMPRESSION=OFF -DENABLE_PUSH=OFF -DCMAKE_DEBUG_POSTFIX=_d  -GNinja -S ${{ github.workspace }} -B ${{ github.workspace }}/_build_shared
+        if: runner.os != 'Windows'
+        run: cmake "-DCMAKE_TOOLCHAIN_FILE=${VCPKG_INSTALLATION_ROOT}/scripts/buildsystems/vcpkg.cmake" -DBUILD_SHARED_LIBS=ON -DCMAKE_INSTALL_PREFIX=${{ github.workspace }}/_install_shared -DENABLE_WARNINGS_AS_ERRORS=ON -DENABLE_COMPRESSION=OFF -DENABLE_PUSH=OFF -DCMAKE_DEBUG_POSTFIX=_d  -GNinja -S ${{ github.workspace }} -B ${{ github.workspace }}/_build_shared
 
       - name: "Build for Unix Shared Libs"
-        if: matrix.dependencies == 'submodule' && runner.os != 'Windows'
+        if: runner.os != 'Windows'
         run: cmake --build ${{ github.workspace }}/_build_shared
 
       - name: "Install for Unix Shared Libs"
-        if: matrix.dependencies == 'submodule' && runner.os != 'Windows'
+        if: runner.os != 'Windows'
         run: cmake --install ${{ github.workspace }}/_build_shared
 
       - name: "Configure pkg-config import for Unix"
-        if: matrix.dependencies == 'submodule' && runner.os != 'Windows'
-        run: cmake -DCMAKE_PREFIX_PATH=${{ github.workspace }}/_install_shared -GNinja -S ${{ github.workspace }}/cmake/project-import-pkgconfig -B ${{ github.workspace }}/_import_pkgconfig
+        if: runner.os != 'Windows'
+        run: cmake "-DCMAKE_TOOLCHAIN_FILE=${VCPKG_INSTALLATION_ROOT}/scripts/buildsystems/vcpkg.cmake" -DCMAKE_PREFIX_PATH=${{ github.workspace }}/_install_shared -GNinja -S ${{ github.workspace }}/cmake/project-import-pkgconfig -B ${{ github.workspace }}/_import_pkgconfig
 
       - name: "Build pkg-config import for Unix"
-        if: matrix.dependencies == 'submodule' && runner.os != 'Windows'
+        if: runner.os != 'Windows'
         run: cmake --build ${{ github.workspace }}/_import_pkgconfig

.github/workflows/linting.yml

@@ -17,12 +17,10 @@ jobs:
       - name: Install dependencies
         run: |
           apt-get update
-          apt-get install -y --no-install-recommends ca-certificates clang-19 cmake git iwyu libbenchmark-dev libcurl4-openssl-dev ninja-build zlib1g-dev
+          apt-get install -y --no-install-recommends ca-certificates clang-19 cmake git iwyu libbenchmark-dev libcivetweb-dev libcurl4-openssl-dev ninja-build zlib1g-dev
 
       - name: Checkout source
         uses: actions/checkout@v7
-        with:
-          submodules: true
 
       - name: "CMake Configure"
         run: cmake -GNinja -DRUN_IWYU=ON -DCMAKE_C_COMPILER=clang-19 -DCMAKE_CXX_COMPILER=clang++-19 -S ${GITHUB_WORKSPACE} -B ${GITHUB_WORKSPACE}/_build

CMakeLists.txt

@@ -21,8 +21,6 @@ option(ENABLE_PULL "Build prometheus-cpp pull library" ON)
 option(ENABLE_PUSH "Build prometheus-cpp push library" ON)
 option(ENABLE_COMPRESSION "Enable gzip compression" ON)
 option(ENABLE_TESTING "Build tests" ON)
-option(USE_THIRDPARTY_LIBRARIES "Use 3rdParty submodules" ON)
-option(THIRDPARTY_CIVETWEB_WITH_SSL "Enable SSL support for embedded civetweb source code")
 option(OVERRIDE_CXX_STANDARD_FLAGS "Force building with -std=c++17 even if the CXXFLAGS are configured differently" ON)
 option(GENERATE_PKGCONFIG "Generate and install pkg-config files" ${UNIX})
 option(RUN_IWYU "Run include-what-you-use" OFF)
@@ -82,11 +80,7 @@ endif()
 include(CheckAtomic)
 
 if(ENABLE_TESTING)
-  if(USE_THIRDPARTY_LIBRARIES)
-    find_package(googlemock-3rdparty CONFIG REQUIRED)
-  else()
-    find_package(GTest 1.8.1 CONFIG REQUIRED)
-  endif()
+  find_package(GTest 1.8.1 CONFIG REQUIRED)
   find_package(benchmark CONFIG)
   enable_testing()
 endif()

README.md

@@ -105,17 +105,21 @@ the [GitHub Workflows](.github/workflows) might help.
 
 ### With CMake
 
-For CMake builds don't forget to fetch the submodules first. Please note that
-[zlib](https://zlib.net/) and [libcurl](https://curl.se/) are not provided by
-the included submodules. In the example below their usage is disabled.
+`prometheus-cpp` does not vendor its dependencies. It expects the following
+libraries to already be installed and discoverable via `find_package()`:
 
-Then build as usual.
+- [civetweb](https://github.com/civetweb/civetweb)
+- [googletest](https://github.com/google/googletest) (optional, needed for `ENABLE_TESTING`)
+- [benchmark](https://github.com/google/benchmark) (optional, needed for benchmarks)
+- [zlib](https://zlib.net/) (optional, needed for `ENABLE_COMPRESSION`)
+- [libcurl](https://curl.se/) (optional, needed for `ENABLE_PUSH`)
 
-``` shell
-# fetch third-party dependencies
-git submodule init
-git submodule update
+Use whichever package manager you prefer to provide them, e.g.
+[vcpkg](#vcpkg), [Conan](#conan), your system's package manager, or a
+manually installed copy. In the example below push support and compression
+are disabled to keep the dependency list minimal.
 
+``` shell
 mkdir _build
 cd _build
 
@@ -155,9 +159,6 @@ configuration options.
 To generate a Debian package you could follow these steps:
 
 ``` shell
-# fetch third-party dependencies
-git submodule update --init
-
 # run cmake
 cmake -B_build -DCPACK_GENERATOR=DEB -DBUILD_SHARED_LIBS=ON # or OFF for static libraries
 

cmake/prometheus-cpp-config.cmake.in

@@ -6,21 +6,13 @@ set_and_check(prometheus-cpp_INCLUDE_DIR "@PACKAGE_CMAKE_INSTALL_INCLUDEDIR@")
 set(PROMETHEUS_CPP_ENABLE_PULL @ENABLE_PULL@)
 set(PROMETHEUS_CPP_ENABLE_PUSH @ENABLE_PUSH@)
 set(PROMETHEUS_CPP_USE_COMPRESSION @ENABLE_COMPRESSION@)
-set(PROMETHEUS_CPP_USE_THIRDPARTY_LIBRARIES @USE_THIRDPARTY_LIBRARIES@)
-set(PROMETHEUS_CPP_THIRDPARTY_CIVETWEB_WITH_SSL @THIRDPARTY_CIVETWEB_WITH_SSL@)
 
 set(CMAKE_THREAD_PREFER_PTHREAD TRUE)
 find_dependency(Threads)
 unset(CMAKE_THREAD_PREFER_PTHREAD)
 
 if(PROMETHEUS_CPP_ENABLE_PULL)
-  if(PROMETHEUS_CPP_USE_THIRDPARTY_LIBRARIES)
-    if(PROMETHEUS_CPP_THIRDPARTY_CIVETWEB_WITH_SSL)
-        find_dependency(OpenSSL)
-    endif()
-  else()
-    find_dependency(civetweb)
-  endif()
+  find_dependency(civetweb)
 endif()
 
 if(PROMETHEUS_CPP_ENABLE_PULL AND PROMETHEUS_CPP_USE_COMPRESSION)

pull/CMakeLists.txt

@@ -1,20 +1,9 @@
-if(USE_THIRDPARTY_LIBRARIES)
-  find_package(civetweb-3rdparty CONFIG REQUIRED)
-  add_library(${PROJECT_NAME}::civetweb ALIAS civetweb)
-  install(
-    TARGETS civetweb
-    EXPORT ${PROJECT_NAME}-targets
-    # keep embedded civetweb headers scoped to prometheus(-cpp)
-    PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/prometheus
-  )
-else()
-  find_package(civetweb CONFIG REQUIRED)
+find_package(civetweb CONFIG REQUIRED)
 
-  # work-around https://github.com/civetweb/civetweb/pull/918
-  if(WIN32 AND NOT TARGET WINSOCK::WINSOCK)
-    add_library(WINSOCK::WINSOCK INTERFACE IMPORTED)
-    target_link_libraries(WINSOCK::WINSOCK INTERFACE ws2_32)
-  endif()
+# work-around https://github.com/civetweb/civetweb/pull/918
+if(WIN32 AND NOT TARGET WINSOCK::WINSOCK)
+  add_library(WINSOCK::WINSOCK INTERFACE IMPORTED)
+  target_link_libraries(WINSOCK::WINSOCK INTERFACE ws2_32)
 endif()
 
 if(ENABLE_COMPRESSION)
@@ -46,7 +35,7 @@ target_link_libraries(pull
   PRIVATE
     ${PROJECT_NAME}::util
     Threads::Threads
-    $<IF:$<BOOL:${USE_THIRDPARTY_LIBRARIES}>,${PROJECT_NAME}::civetweb,civetweb::civetweb-cpp>
+    civetweb::civetweb-cpp
     $<$<AND:$<BOOL:${UNIX}>,$<NOT:$<BOOL:${APPLE}>>>:rt>
     $<$<BOOL:${ENABLE_COMPRESSION}>:ZLIB::ZLIB>
 )
@@ -95,9 +84,7 @@ if(GENERATE_PKGCONFIG)
   set(PKGCONFIG_LIBS)
   set(PKGCONFIG_REQUIRES)
 
-  if(NOT USE_THIRDPARTY_LIBRARIES)
-    string(APPEND PKGCONFIG_LIBS " -lcivetweb-cpp -lcivetweb")
-  endif()
+  string(APPEND PKGCONFIG_LIBS " -lcivetweb-cpp -lcivetweb")
 
   if(ENABLE_COMPRESSION)
     string(APPEND PKGCONFIG_REQUIRES " zlib")