systemd: add templated systemd unit files

These allow running multiple instances of wireplumber with
different config files. The config file is denoted on the service
name, ex: wireplumber@bluetooth loads bluetooth.conf

src/systemd/meson.build

@@ -3,6 +3,7 @@ systemd = dependency('systemd', required: get_option('systemd'))
 if systemd.found()
   systemd_config = configuration_data()
   systemd_config.set('WP_BINARY', join_paths(wireplumber_bin_dir, 'wireplumber'))
+  systemd_config.set('WP_CONFIG_DIR', wireplumber_config_dir)
 
   # system service
   if get_option('systemd-system-service')

src/systemd/system/meson.build

@@ -2,3 +2,7 @@ configure_file(input : 'wireplumber.service.in',
                output : 'wireplumber.service',
                configuration : systemd_config,
                install_dir : systemd_system_unit_dir)
+configure_file(input : 'wireplumber@.service.in',
+               output : 'wireplumber@.service',
+               configuration : systemd_config,
+               install_dir : systemd_system_unit_dir)

src/systemd/system/wireplumber@.service.in

+[Unit]
+Description=Multimedia Service Session Manager (%i)
+After=pipewire.service
+BindsTo=pipewire.service
+AssertPathExists=@WP_CONFIG_DIR@/%i.conf
+
+[Service]
+LockPersonality=yes
+MemoryDenyWriteExecute=yes
+NoNewPrivileges=yes
+RestrictNamespaces=yes
+SystemCallArchitectures=native
+SystemCallFilter=@system-service
+Type=simple
+ExecStart=@WP_BINARY@ -c %i.conf
+Restart=on-failure
+User=pipewire
+Environment=PIPEWIRE_RUNTIME_DIR=%t/pipewire
+
+[Install]
+WantedBy=pipewire.service

src/systemd/user/meson.build

@@ -2,3 +2,7 @@ configure_file(input : 'wireplumber.service.in',
                output : 'wireplumber.service',
                configuration : systemd_config,
                install_dir : systemd_user_unit_dir)
+configure_file(input : 'wireplumber@.service.in',
+               output : 'wireplumber@.service',
+               configuration : systemd_config,
+               install_dir : systemd_user_unit_dir)

src/systemd/user/wireplumber@.service.in

+[Unit]
+Description=Multimedia Service Session Manager (%i)
+After=pipewire.service
+BindsTo=pipewire.service
+AssertPathExists=@WP_CONFIG_DIR@/%i.conf
+
+[Service]
+LockPersonality=yes
+MemoryDenyWriteExecute=yes
+NoNewPrivileges=yes
+RestrictNamespaces=yes
+SystemCallArchitectures=native
+SystemCallFilter=@system-service
+Type=simple
+ExecStart=@WP_BINARY@ -c %i.conf
+Restart=on-failure
+Slice=session.slice
+
+[Install]
+WantedBy=pipewire.service