Unverified Commit 15be453e authored by Will Fancher's avatar Will Fancher Committed by GitHub
Browse files

switch-to-configuration: Better handling of socket-activated units (#359724)

parents b25a2b5f bc1cfec9

nixos/doc/manual/development/unit-handling.section.md

+10 −5
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@@ -58,11 +58,16 @@ checks: 
    before the activation script is run. This behavior is different when the

    service is socket-activated, as outlined in the following steps.



  - The last thing that is taken into account is whether the unit is a service

    and socket-activated. If `X-StopIfChanged` is **not** set, the service

    is **restart**ed with the others. If it is set, both the service and the

    socket are **stop**ped and the socket is **start**ed, leaving socket

    activation to start the service when it's needed.

  - The last thing that is taken into account is whether the unit is a

    service and socket-activated. A correspondence between a

    `.service` and its `.socket` unit is detected automatically, but

    services can **opt out** of that detection by setting

    `X-NotSocketActivated` to `yes` in their `[Service]`

    section. Otherwise, if `X-StopIfChanged` is **not** set, the

    service is **restart**ed with the others. If it is set, both the

    service and the socket are **stop**ped and the socket is

    **start**ed, leaving socket activation to start the service when

    it's needed.



## Sysinit reactivation {#sec-sysinit-reactivation}

nixos/lib/systemd-lib.nix

+3 −0
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@@ -579,6 +579,9 @@ in rec { 
      '' else "")

       + optionalString (def ? stopIfChanged && !def.stopIfChanged) ''

         X-StopIfChanged=false

      ''

       + optionalString (def ? notSocketActivated && def.notSocketActivated) ''

         X-NotSocketActivated=true

      '' + attrsToSection def.serviceConfig);

    };

nixos/lib/systemd-unit-options.nix

+12 −0
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@@ -535,6 +535,18 @@ in rec { 
        '';

      };



      notSocketActivated = mkOption {

        type = types.bool;

        default = false;

        description = ''

          If set, a changed unit is never assumed to be

          socket-activated on configuration switch, even if

          it might have associated socket units. Instead, the unit

          will be restarted (or stopped/started) as if it had no

          associated sockets.

        '';

      };



      startAt = mkOption {

        type = with types; either str (listOf str);

        default = [];

nixos/modules/services/hardware/udev.nix

+4 −4
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@@ -459,10 +459,10 @@ in 
      fi

    '';



    systemd.services.systemd-udevd =

      { restartTriggers = [ config.environment.etc."udev/rules.d".source ];

    systemd.services.systemd-udevd = {

      restartTriggers = [ config.environment.etc."udev/rules.d".source ];

      notSocketActivated = true;

    };



  };



  imports = [

nixos/modules/system/activation/switch-to-configuration.pl

+7 −0
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@@ -544,6 +544,13 @@ sub handle_modified_unit { ## no critic(Subroutines::ProhibitManyArgs, Subroutin 
                    }

                }



                if (parse_systemd_bool(\%new_unit_info, "Service", "X-NotSocketActivated", 0)) {

                    # If the unit explicitly opts out of socket

                    # activation, restart it as if it weren't (but do

                    # restart its sockets, that's fine):

                    $socket_activated = 0;

                }



                # If the unit is not socket-activated, record

                # that this unit needs to be started below.

                # We write this to a file to ensure that the