From 5c7c16a3b6034b8ee7e40bd9d70d9597f85c6c96 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Charlotte=20=F0=9F=A6=9D=20Delenk?= <lotte@chir.rs>
Date: Tue, 27 Sep 2022 07:49:06 +0100
Subject: [PATCH] fix activation script

---
 extra/switch-to-configuration.pl | 30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/extra/switch-to-configuration.pl b/extra/switch-to-configuration.pl
index 52f84b09..9c65fc2a 100644
--- a/extra/switch-to-configuration.pl
+++ b/extra/switch-to-configuration.pl
@@ -18,7 +18,8 @@ use Config::IniFiles;
 use File::Path qw(make_path);
 use File::Basename;
 use File::Slurp qw(read_file write_file edit_file);
-use Net::DBus;
+use JSON::PP;
+use IPC::Cmd;
 use Sys::Syslog qw(:standard :macros);
 use Cwd qw(abs_path);
 
@@ -91,7 +92,7 @@ make_path("/run/nixos", { mode => oct(755) });
 openlog("nixos", "", LOG_USER);
 
 # Install or update the bootloader.
-if ($action eq "boot") {
+if ($action eq "switch") {
     chomp(my $install_boot_loader = <<'EOFBOOTLOADER');
 @installBootLoader@
 EOFBOOTLOADER
@@ -124,12 +125,29 @@ EOF
 # virtual console 1 and we restart the "tty1" unit.
 $SIG{PIPE} = "IGNORE";
 
+# Replacement for Net::DBus that calls busctl of the current systemd, parses
+# it's json output and returns the response using only core modules to reduce
+# dependencies on perlPackages in baseSystem
+sub busctl_call_systemd1_mgr {
+    my (@args) = @_;
+    my $cmd = [
+        "$cur_systemd/busctl", "--json=short", "call", "org.freedesktop.systemd1",
+        "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager",
+        @args
+    ];
+
+    my ($ok, $err, undef, $stdout) = IPC::Cmd::run(command => $cmd);
+    die $err unless $ok;
+
+    my $res = decode_json(join "", @$stdout);
+    return $res;
+}
+
 # Asks the currently running systemd instance via dbus which units are active.
 # Returns a hash where the key is the name of each unit and the value a hash
 # of load, state, substate.
 sub get_active_units {
-    my $mgr = Net::DBus->system->get_service("org.freedesktop.systemd1")->get_object("/org/freedesktop/systemd1");
-    my $units = $mgr->ListUnitsByPatterns([], []);
+    my $units = busctl_call_systemd1_mgr("ListUnitsByPatterns", "asas", 0, 0)->{data}->[0];
     my $res = {};
     for my $item (@{$units}) {
         my ($id, $description, $load_state, $active_state, $sub_state,
@@ -149,9 +167,7 @@ sub get_active_units {
 # Takes the name of the unit as an argument and returns a bool whether the unit is active or not.
 sub unit_is_active {
     my ($unit_name) = @_;
-
-    my $mgr = Net::DBus->system->get_service("org.freedesktop.systemd1")->get_object("/org/freedesktop/systemd1");
-    my $units = $mgr->ListUnitsByNames([$unit_name]);
+    my $units = busctl_call_systemd1_mgr("ListUnitsByNames", "as", 1, $unit_name)->{data}->[0];
     if (scalar(@{$units}) == 0) {
         return 0;
     }