From 7a792624925d46690c1f07fe4b194b5f4c510db6 Mon Sep 17 00:00:00 2001
From: Paulo Neves <ptsneves@gmail.com>
Date: Tue, 2 Aug 2022 09:57:05 +0200
Subject: [PATCH 1/1] build: Make systemd init systemd detection contingent on
 pkgconfig

Use pkg-config to get systemd.pc variables and systemdunitdir. Those
variable ensure that .service files are installed in the correct paths
and only when systemd is detected.

Upstream-Status: Pending [https://github.com/fluent/fluent-bit/pull/5818]

---
 cmake/FindJournald.cmake | 4 ++++
 src/CMakeLists.txt       | 4 ++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/cmake/FindJournald.cmake b/cmake/FindJournald.cmake
index f5a3a832b..9e6657a29 100644
--- a/cmake/FindJournald.cmake
+++ b/cmake/FindJournald.cmake
@@ -5,6 +5,8 @@
 #  JOURNALD_INCLUDE_DIR - the Journald include directory
 #  JOURNALD_LIBRARIES - Link these to use Journald
 #  JOURNALD_DEFINITIONS - Compiler switches required for using Journald
+#  SYSTEMD_UNITDIR - The systemd units' directory
+#
 # Redistribution and use is allowed according to the terms of the BSD license.
 # For details see the accompanying COPYING-CMAKE-SCRIPTS file.
 #
@@ -16,7 +18,9 @@
 # in the FIND_PATH() and FIND_LIBRARY() calls
 find_package(PkgConfig)
 pkg_check_modules(PC_JOURNALD QUIET systemd)
+pkg_get_variable(PC_SYSTEMD_UNITDIR systemd "systemdsystemunitdir")
 
+set(SYSTEMD_UNITDIR ${PC_SYSTEMD_UNITDIR})
 set(JOURNALD_FOUND ${PC_JOURNALD_FOUND})
 set(JOURNALD_DEFINITIONS ${PC_JOURNALD_CFLAGS_OTHER})
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 522bbf9bd..30743d8d6 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -480,13 +480,13 @@ if(FLB_BINARY)
   endif()
 
   # Detect init system, install upstart, systemd or init.d script
-  if(IS_DIRECTORY /lib/systemd/system)
+  if(DEFINED SYSTEMD_UNITDIR)
     set(FLB_SYSTEMD_SCRIPT "${PROJECT_SOURCE_DIR}/init/${FLB_OUT_NAME}.service")
     configure_file(
       "${PROJECT_SOURCE_DIR}/init/systemd.in"
       ${FLB_SYSTEMD_SCRIPT}
       )
-    install(FILES ${FLB_SYSTEMD_SCRIPT} COMPONENT binary DESTINATION /lib/systemd/system)
+    install(FILES ${FLB_SYSTEMD_SCRIPT} COMPONENT binary DESTINATION ${SYSTEMD_UNITDIR})
     install(DIRECTORY DESTINATION ${FLB_INSTALL_CONFDIR} COMPONENT binary)
   elseif(IS_DIRECTORY /usr/share/upstart)
     set(FLB_UPSTART_SCRIPT "${PROJECT_SOURCE_DIR}/init/${FLB_OUT_NAME}.conf")
-- 
2.25.1