env.d: Port the environment generators to use --print-updated-env

This reduces the amount of shell in use, and the number of subprocesses
spawned by that, so our system environment generator is as fast as
possible when used in the critical startup path.

It adds a new system environment generator so that the system flatpak
installation can be used outside of a user session. In particular, this
allows enumeration of system-installed flatpaks in gnome-initial-setup
in order to set parental controls on them.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

Makefile.am

@@ -161,13 +161,16 @@ if INSTALL_GDM_ENV_FILE
 env_DATA += flatpak.env
 endif
 
-EXTRA_DIST += env.d/flatpak.env.in env.d/60-flatpak
+EXTRA_DIST += env.d/flatpak.env.in env.d/60-flatpak env.d/60-flatpak-system-only
 DISTCLEANFILES += flatpak.env
 
 flatpak.env: env.d/flatpak.env.in
 	$(AM_V_GEN) $(SED) -e "s|\@localstatedir\@|$(localstatedir)|" \
 		-e "s|\@sysconfdir\@|$(sysconfdir)|" $< > $@
 
+systemenvgendir = $(systemdsystemenvgendir)
+systemenvgen_SCRIPTS = env.d/60-flatpak-system-only
+
 userenvgendir = $(systemduserenvgendir)
 userenvgen_SCRIPTS = env.d/60-flatpak
 

configure.ac

@@ -122,6 +122,15 @@ AC_ARG_WITH([systemdsystemunitdir],
     [with_systemdsystemunitdir='${prefix}/lib/systemd/system'])
 AC_SUBST([systemdsystemunitdir], [$with_systemdsystemunitdir])
 
+AC_ARG_WITH([systemdsystemenvgendir],
+            [AS_HELP_STRING([--with-systemdsystemenvgendir=DIR],
+                            [Directory for systemd system environment generators (default=PREFIX/lib/systemd/system-environment-generators)])],
+    [],
+    dnl This is deliberately not ${libdir}: systemd units always go in
+    dnl .../lib, never .../lib64 or .../lib/x86_64-linux-gnu
+    [with_systemdsystemenvgendir='${prefix}/lib/systemd/system-environment-generators'])
+AC_SUBST([systemdsystemenvgendir], [$with_systemdsystemenvgendir])
+
 AC_ARG_WITH([systemduserenvgendir],
             [AS_HELP_STRING([--with-systemduserenvgendir=DIR],
                             [Directory for systemd user environment generators (default=PREFIX/lib/systemd/user-environment-generators)])],

env.d/60-flatpak

@@ -1,15 +1,2 @@
-#!/bin/bash
-
-new_dirs=
-while read -r install_path
-do
-    share_path=$install_path/exports/share
-    case ":$XDG_DATA_DIRS:" in
-        *":$share_path:"*) :;;
-        *":$share_path/:"*) :;;
-        *) new_dirs=${new_dirs:+${new_dirs}:}$share_path;;
-    esac
-done < <(echo "${XDG_DATA_HOME:-"$HOME/.local/share"}/flatpak"; flatpak  --installations)
-
-XDG_DATA_DIRS="${new_dirs:+${new_dirs}:}${XDG_DATA_DIRS:-/usr/local/share:/usr/share}"
-echo "XDG_DATA_DIRS=$XDG_DATA_DIRS"
+#!/bin/sh
+exec flatpak --print-updated-env

env.d/60-flatpak-system-only

@@ -0,0 +1,2 @@
+#!/bin/sh
+exec flatpak --print-updated-env --print-system-only