Unverified Commit 9bfd0d68 authored by r-vdp's avatar r-vdp
Browse files

nixos/activation: avoid build failure with large activation script 

Two improvements:
* use `writeShellApplication` (which uses `passAsFile` instead of
  passing the activation script as an env var into the derivation.
  We disable shellcheck and the bash options that this builder
  usually adds to avoid issues with out-of-tree activation scripts.
* use `sed` instead of `substituteInPlace`, since the substitute
  functions load the file content into a shell variable

This avoids issues when the activation is too long to fit in a shell variable.
Before this commit, a very large activation script, would cause build
failures because of different limits on the file content size, e.g.
```
➜ nix build -f . nixosTests.restartByActivationScript.nodes.machine.system.build.toplevel -vL
this derivation will be built:
  /nix/store/xw6anpfjyamnycjg58cmj01sz3ididyl-nixos-system-machine-test.drv
building '/nix/store/xw6anpfjyamnycjg58cmj01sz3ididyl-nixos-system-machine-test.drv'...
nixos-system-machine-test> error: executing '/nix/store/rlq03x4cwf8zn73hxaxnx0zn5q9kifls-bash-5.3p3/bin/bash': Argument list too long
error: builder for '/nix/store/xw6anpfjyamnycjg58cmj01sz3ididyl-nixos-system-machine-test.drv' failed with exit code 1;
       last 1 log lines:
       > error: executing '/nix/store/rlq03x4cwf8zn73hxaxnx0zn5q9kifls-bash-5.3p3/bin/bash': Argument list too long
       For full logs, run:
        nix log /nix/store/xw6anpfjyamnycjg58cmj01sz3ididyl-nixos-system-machine-test.drv
```
parent d8ed3999

nixos/modules/system/activation/activatable-system.nix

+41 −32
Original line number Diff line number Diff line
@@ -11,12 +11,6 @@ let 
    mkOption

    types

    ;



  systemBuilderArgs = {

    activationScript = config.system.activationScripts.script;

    dryActivationScript = config.system.dryActivationScript;

  };



in

{

  options = {
@@ -52,33 +46,48 @@ in 
      '';

    };

  };

  config = {

    system.activatableSystemBuilderCommands = ''

      echo "$activationScript" > $out/activate

      echo "$dryActivationScript" > $out/dry-activate

      substituteInPlace $out/activate --subst-var-by out ''${!toplevelVar}

      substituteInPlace $out/dry-activate --subst-var-by out ''${!toplevelVar}

      chmod u+x $out/activate $out/dry-activate

      unset activationScript dryActivationScript

  config =

    let

      activationScript = lib.getExe (

        pkgs.writeShellApplication {

          name = "activate";

          text = config.system.activationScripts.script;

          checkPhase = "";

          bashOptions = [ ];

        }

      );

      dryActivationScript = lib.getExe (

        pkgs.writeShellApplication {

          name = "dry-activate";

          text = config.system.dryActivationScript;

          checkPhase = "";

          bashOptions = [ ];

        }

      );

    in

    {

      system.activatableSystemBuilderCommands =

        # We use sed here instead of substitute(InPlace), because the substitute

        # functions load the content of the file into a bash variable, which fails

        # for very large activation scripts.

        # bash

        ''

          cp ${activationScript} $out/activate

          cp ${dryActivationScript} $out/dry-activate

          ${lib.getExe pkgs.gnused} --in-place --expression "s|@out@|''${!toplevelVar}|g" $out/activate $out/dry-activate

        '';



      system.systemBuilderCommands = lib.mkIf config.system.activatable config.system.activatableSystemBuilderCommands;

    system.systemBuilderArgs = lib.mkIf config.system.activatable (

      systemBuilderArgs

      // {

      system.systemBuilderArgs = lib.mkIf config.system.activatable {

        toplevelVar = "out";

      }

    );

      };



      system.build.separateActivationScript =

        pkgs.runCommand "separate-activation-script"

        (

          systemBuilderArgs

          // {

          {

            toplevelVar = "toplevel";

            toplevel = config.system.build.toplevel;

          }

        )

          ''

            mkdir $out

            ${config.system.activatableSystemBuilderCommands}

nixos/modules/system/activation/activation-script.nix

+0 −2
Original line number Diff line number Diff line
@@ -50,8 +50,6 @@ let 
      ) withHeadlines;

    in

    ''

      #!${pkgs.runtimeShell}



      source ${./lib/lib.sh}



      systemConfig='@out@'

nixos/tests/restart-by-activation-script.nix

+9 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ 
  };



  nodes.machine =

    { pkgs, ... }:

    { pkgs, lib, ... }:

    {

      imports = [ ../modules/profiles/minimal.nix ];
@@ -46,6 +46,14 @@ 
          fi

        '';

      };



      # Make sure we don't crash on long activation scripts

      specialisation.longscript.configuration = {

        system.activationScripts.long = {

          supportsDryActivation = true;

          text = lib.concatStringsSep "\n" (lib.genList (i: ''# line number ${toString i}'') 1000000);

        };

      };

    };



  testScript = # python