Put debian/postinst.in in separate file

Signed-off-by: Amin Vakil <info@aminvakil.com>

Author: aminvakil

CMakeLists.txt

@@ -1558,14 +1558,10 @@ ldconfig
     list(APPEND CPACK_DEBIAN_RUNTIME_PACKAGE_CONTROL_EXTRA "${PROJECT_BINARY_DIR}/scripts/postinst;${PROJECT_BINARY_DIR}/scripts/prerm")
   endif(FLB_RUN_LDCONFIG)
 
-  file(WRITE ${PROJECT_BINARY_DIR}/scripts/postinst "#!/bin/sh
-set -e
-${LDCONFIG_SCRIPT_CMDS}
-if [ \"\$1\" = \"configure\" ]; then
-    systemctl --system daemon-reload >/dev/null || true
-    systemctl try-restart ${FLB_OUT_NAME}.service >/dev/null || true
-fi
-")
+  configure_file(
+    ${CMAKE_CURRENT_SOURCE_DIR}/cpack/debian/postinst.in
+    ${PROJECT_BINARY_DIR}/scripts/postinst
+  )
 
   list(APPEND CPACK_DEBIAN_RUNTIME_PACKAGE_CONTROL_EXTRA "${PROJECT_BINARY_DIR}/scripts/postinst;${PROJECT_BINARY_DIR}/scripts/prerm")
 

cpack/debian/postinst.in

@@ -0,0 +1,7 @@
+#!/bin/sh
+set -e
+@LDCONFIG_POSTINST_CMDS@
+if [ "$1" = "configure" ]; then
+    systemctl --system daemon-reload >/dev/null || true
+    systemctl try-restart @FLB_OUT_NAME@.service >/dev/null || true
+fi