nixos/dbus: fix switching from dbus-broker to dbus backport-309068-to-release-23.11

(cherry picked from commit 21ab17debeab844336d2c064471ba984200b3c8a)

2 files changed, 15 insertions, 0 deletions

diff --git a/nixos/modules/services/system/dbus.nix b/nixos/modules/services/system/dbus.nix
index 8d5b25e617625..7d6b85e2b79b8 100644
--- a/nixos/modules/services/system/dbus.nix
+++ b/nixos/modules/services/system/dbus.nix
@@ -145,6 +145,10 @@ in
       };
 
       systemd.services.dbus = {
+        aliases = [
+          # hack aiding to prevent dbus from restarting when switching from dbus-broker back to dbus
+          "dbus-broker.service"
+        ];
         # Don't restart dbus-daemon. Bad things tend to happen if we do.
         reloadIfChanged = true;
         restartTriggers = [
@@ -156,6 +160,10 @@ in
       };
 
       systemd.user.services.dbus = {
+        aliases = [
+          # hack aiding to prevent dbus from restarting when switching from dbus-broker back to dbus
+          "dbus-broker.service"
+        ];
         # Don't restart dbus-daemon. Bad things tend to happen if we do.
         reloadIfChanged = true;
         restartTriggers = [
@@ -182,6 +190,8 @@ in
       # https://github.com/NixOS/nixpkgs/issues/108643
       systemd.services.dbus-broker = {
         aliases = [
+          # allow other services to just depend on dbus,
+          # but also a hack aiding to prevent dbus from restarting when switching from dbus-broker back to dbus
           "dbus.service"
         ];
         # Don't restart dbus. Bad things tend to happen if we do.
@@ -196,6 +206,8 @@ in
 
       systemd.user.services.dbus-broker = {
         aliases = [
+          # allow other services to just depend on dbus,
+          # but also a hack aiding to prevent dbus from restarting when switching from dbus-broker back to dbus
           "dbus.service"
         ];
         # Don't restart dbus. Bad things tend to happen if we do.
diff --git a/nixos/modules/system/activation/switch-to-configuration.pl b/nixos/modules/system/activation/switch-to-configuration.pl
index e2f66a287bc4f..15045f023f0eb 100755
--- a/nixos/modules/system/activation/switch-to-configuration.pl
+++ b/nixos/modules/system/activation/switch-to-configuration.pl
@@ -472,6 +472,9 @@ sub handle_modified_unit { ## no critic(Subroutines::ProhibitManyArgs, Subroutin
             $units_to_reload->{$unit} = 1;
             record_unit($reload_list_file, $unit);
         }
+        elsif ($unit eq "dbus.service" || $unit eq "dbus-broker.service") {
+            # dbus service should only ever be reloaded, not started/stoped/restarted as that would break the system.
+        }
         elsif (!parse_systemd_bool(\%new_unit_info, "Service", "X-RestartIfChanged", 1) || parse_systemd_bool(\%new_unit_info, "Unit", "RefuseManualStop", 0) || parse_systemd_bool(\%new_unit_info, "Unit", "X-OnlyManualStart", 0)) {
             $units_to_skip->{$unit} = 1;
         } else {