build: use the system provided libnghttp2 if found

e.g. buildroot has logic to build libnghttp2,
so if pkg_check_modules can find a suitable version,
then use that one if -DFLB_PREFER_SYSTEM_LIB_NGHTTP2=Yes.

Signed-off-by: Thomas Devoogdt <[email protected]>

Author: ThomasDevoogdt

CMakeLists.txt

@@ -204,6 +204,7 @@ option(FLB_RUN_LDCONFIG "Enable execution of ldconfig after installation" No)
 # Prefer system libraries if available
 option(FLB_PREFER_SYSTEM_LIBS             "Prefer system libraries"                   No)
 option(FLB_PREFER_SYSTEM_LIB_LUAJIT       "Prefer the libluajit system library"       ${FLB_PREFER_SYSTEM_LIBS})
+option(FLB_PREFER_SYSTEM_LIB_NGHTTP2      "Prefer the libnghttp2 system library"      ${FLB_PREFER_SYSTEM_LIBS})
 
 # Enable all features
 if(FLB_ALL)
@@ -489,13 +490,16 @@ add_subdirectory(${FLB_PATH_LIB_CMETRICS} EXCLUDE_FROM_ALL)
 add_subdirectory(${FLB_PATH_LIB_CTRACES} EXCLUDE_FROM_ALL)
 
 # Nghttp2 options
-FLB_OPTION(ENABLE_LIB_ONLY   ON)
-FLB_OPTION(ENABLE_STATIC_LIB ON)
-FLB_OPTION(ENABLE_SHARED_LIB OFF)
-
-FLB_DEFINITION(NGHTTP2_STATICLIB)
-
-add_subdirectory(${FLB_PATH_LIB_NGHTTP2} EXCLUDE_FROM_ALL)
+if(FLB_PREFER_SYSTEM_LIB_NGHTTP2)
+  find_package(PkgConfig)
+  pkg_check_modules(NGHTTP2 libnghttp2>=1.0.0)
+endif()
+if(NGHTTP2_FOUND)
+  include_directories(${NGHTTP2_INCLUDE_DIRS})
+  link_directories(${NGHTTP2_LIBRARY_DIRS})
+else()
+  include(cmake/nghttp2.cmake)
+endif()
 
 # C-Ares (DNS library)
 FLB_OPTION(CARES_STATIC      ON)

cmake/headers.cmake

@@ -42,10 +42,6 @@ include_directories(
 
   ${CMAKE_CURRENT_BINARY_DIR}/lib/monkey/include/
   ${CMAKE_CURRENT_BINARY_DIR}/lib/monkey/include/monkey/
-
-  ${CMAKE_CURRENT_BINARY_DIR}/lib/nghttp2
-  ${CMAKE_CURRENT_BINARY_DIR}/lib/nghttp2/lib/includes/
-  ${FLB_PATH_ROOT_SOURCE}/${FLB_PATH_LIB_NGHTTP2}/lib/includes/
   )
 
 if(FLB_IN_KAFKA OR FLB_OUT_KAFKA)

cmake/nghttp2.cmake

@@ -0,0 +1,12 @@
+# nghttp2 cmake
+FLB_OPTION(ENABLE_LIB_ONLY   ON)
+FLB_OPTION(ENABLE_STATIC_LIB ON)
+FLB_OPTION(ENABLE_SHARED_LIB OFF)
+FLB_DEFINITION(NGHTTP2_STATICLIB)
+include_directories(
+  ${CMAKE_CURRENT_BINARY_DIR}/lib/nghttp2
+  ${CMAKE_CURRENT_BINARY_DIR}/lib/nghttp2/lib/includes/
+  ${FLB_PATH_ROOT_SOURCE}/${FLB_PATH_LIB_NGHTTP2}/lib/includes/
+)
+add_subdirectory(${FLB_PATH_LIB_NGHTTP2} EXCLUDE_FROM_ALL)
+set(NGHTTP2_LIBRARIES "nghttp2_static")

src/CMakeLists.txt

@@ -388,7 +388,7 @@ set(FLB_DEPS
   c-ares
   snappy-c
   lwrb
-  nghttp2_static
+  ${NGHTTP2_LIBRARIES}
   )
 
 if(OPENSSL_FOUND)