depot/third_party/nixpkgs/nixos/modules/tasks/filesystems/envfs.nix
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GitOrigin-RevId: 724bfc0892363087709bd3a5a1666296759154b1
2023-02-09 12:40:11 +01:00

59 lines
1.9 KiB
Nix

{ pkgs, config, lib, ... }:
let
cfg = config.services.envfs;
mounts = {
"/usr/bin" = {
device = "none";
fsType = "envfs";
options = [
"fallback-path=${pkgs.runCommand "fallback-path" {} (''
mkdir -p $out
ln -s ${config.environment.usrbinenv} $out/env
ln -s ${config.environment.binsh} $out/sh
'' + cfg.extraFallbackPathCommands)}"
];
};
"/bin" = {
device = "/usr/bin";
fsType = "none";
options = [ "bind" ];
};
};
in {
options = {
services.envfs = {
enable = lib.mkEnableOption (lib.mdDoc "Envfs filesystem") // {
description = lib.mdDoc ''
Fuse filesystem that returns symlinks to executables based on the PATH
of the requesting process. This is useful to execute shebangs on NixOS
that assume hard coded locations in locations like /bin or /usr/bin
etc.
'';
};
package = lib.mkOption {
type = lib.types.package;
default = pkgs.envfs;
defaultText = lib.literalExpression "pkgs.envfs";
description = lib.mdDoc "Which package to use for the envfs.";
};
extraFallbackPathCommands = lib.mkOption {
type = lib.types.lines;
default = "";
example = "ln -s $''{pkgs.bash}/bin/bash $out/bash";
description = lib.mdDoc "Extra commands to run in the package that contains fallback executables in case not other executable is found";
};
};
};
config = lib.mkIf (cfg.enable) {
environment.systemPackages = [ cfg.package ];
# we also want these mounts in virtual machines.
fileSystems = if config.virtualisation ? qemu then lib.mkVMOverride mounts else mounts;
# We no longer need those when using envfs
system.activationScripts.usrbinenv = lib.mkForce "";
system.activationScripts.binsh = lib.mkForce "";
};
}