nixpkgs/nixos/modules/tasks/filesystems/envfs.nix
2022-12-28 16:03:49 +01:00

51 lines
1.5 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 ${pkgs.coreutils}/bin/env $out/env
ln -s ${config.system.build.binsh}/bin/sh $out/sh
''}"
];
};
"/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;
description = lib.mdDoc "Which package to use for the envfs.";
default = pkgs.envfs;
defaultText = lib.mdDoc "pkgs.envfs";
};
};
};
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 "";
};
}