Find the correct install paths for systemd units and udev rules

cmake/FindSystemd.cmake

@@ -0,0 +1,34 @@
+# - Try to find Systemd
+# Once done this will define
+#
+# SYSTEMD_FOUND - system has systemd
+# SYSTEMD_USER_UNIT_INSTALL_DIR - the systemd system unit install directory
+# SYSTEMD_SYSTEM_UNIT_INSTALL_DIR - the systemd user unit install directory
+
+IF (NOT WIN32)
+
+    find_package(PkgConfig QUIET)
+    if(PKG_CONFIG_FOUND)
+        pkg_check_modules(SYSTEMD "systemd")
+    endif()
+
+    if (SYSTEMD_FOUND)
+        execute_process(COMMAND ${PKG_CONFIG_EXECUTABLE}
+            --variable=systemduserunitdir systemd
+            OUTPUT_VARIABLE SYSTEMD_USER_UNIT_INSTALL_DIR)
+
+        string(REGEX REPLACE "[ \t\n]+" "" SYSTEMD_USER_UNIT_INSTALL_DIR
+            "${SYSTEMD_USER_UNIT_INSTALL_DIR}")
+
+        execute_process(COMMAND ${PKG_CONFIG_EXECUTABLE}
+            --variable=systemdsystemunitdir systemd
+            OUTPUT_VARIABLE SYSTEMD_SYSTEM_UNIT_INSTALL_DIR)
+
+        string(REGEX REPLACE "[ \t\n]+" "" SYSTEMD_SYSTEM_UNIT_INSTALL_DIR
+            "${SYSTEMD_SYSTEM_UNIT_INSTALL_DIR}")
+
+        mark_as_advanced(SYSTEMD_USER_UNIT_INSTALL_DIR SYSTEMD_SYSTEM_UNIT_INSTALL_DIR)
+
+    endif ()
+
+ENDIF ()

cmake/FindUdev.cmake

@@ -0,0 +1,28 @@
+# - Try to find Udev
+# Once done this will define
+#
+# UDEV_FOUND - system has udev
+# UDEV_RULES_INSTALL_DIR - the udev rules install directory
+
+IF (NOT WIN32)
+
+    find_package(PkgConfig QUIET)
+    if(PKG_CONFIG_FOUND)
+        pkg_check_modules(UDEV "udev")
+    endif()
+
+    if (UDEV_FOUND)
+        execute_process(COMMAND ${PKG_CONFIG_EXECUTABLE}
+            --variable=udevdir udev
+            OUTPUT_VARIABLE UDEV_RULES_INSTALL_DIR)
+
+        string(REGEX REPLACE "[ \t\n]+" "" UDEV_RULES_INSTALL_DIR
+            "${UDEV_RULES_INSTALL_DIR}")
+
+        set(UDEV_RULES_INSTALL_DIR "${UDEV_RULES_INSTALL_DIR}/rules.d")
+
+        mark_as_advanced(UDEV_RULES_INSTALL_DIR)
+
+    endif ()
+
+ENDIF ()

cmake/packaging/linux.cmake

@@ -8,10 +8,13 @@ if(${SUNSHINE_BUILD_APPIMAGE} OR ${SUNSHINE_BUILD_FLATPAK})
     install(FILES "${CMAKE_CURRENT_BINARY_DIR}/sunshine.service"
             DESTINATION "${SUNSHINE_ASSETS_DIR}/systemd/user")
 else()
+    find_package(Systemd)
+    find_package(Udev)
+
     install(FILES "${SUNSHINE_SOURCE_ASSETS_DIR}/linux/misc/85-sunshine.rules"
-            DESTINATION "${CMAKE_INSTALL_LIBDIR}/udev/rules.d")
+            DESTINATION "${UDEV_RULES_INSTALL_DIR}")
     install(FILES "${CMAKE_CURRENT_BINARY_DIR}/sunshine.service"
-            DESTINATION "${CMAKE_INSTALL_LIBDIR}/systemd/user")
+            DESTINATION "${SYSTEMD_USER_UNIT_INSTALL_DIR}")
 endif()
 
 # Post install

docker/debian-bookworm.dockerfile

@@ -61,6 +61,7 @@ apt-get install -y --no-install-recommends \
   libxtst-dev \
   nodejs \
   npm \
+  udev \
   wget
 if [[ "${TARGETPLATFORM}" == 'linux/amd64' ]]; then
   apt-get install -y --no-install-recommends \

docker/debian-bullseye.dockerfile

@@ -60,6 +60,7 @@ apt-get install -y --no-install-recommends \
   libxfixes-dev \
   libxrandr-dev \
   libxtst-dev \
+  udev \
   wget
 if [[ "${TARGETPLATFORM}" == 'linux/amd64' ]]; then
   apt-get install -y --no-install-recommends \

docker/ubuntu-20.04.dockerfile

@@ -61,6 +61,7 @@ apt-get install -y --no-install-recommends \
   libxfixes-dev \
   libxrandr-dev \
   libxtst-dev \
+  udev \
   wget
 if [[ "${TARGETPLATFORM}" == 'linux/amd64' ]]; then
   apt-get install -y --no-install-recommends \

docker/ubuntu-22.04.dockerfile

@@ -60,6 +60,7 @@ apt-get install -y --no-install-recommends \
   libxfixes-dev \
   libxrandr-dev \
   libxtst-dev \
+  udev \
   wget
 if [[ "${TARGETPLATFORM}" == 'linux/amd64' ]]; then
   apt-get install -y --no-install-recommends \