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What happens if I push all of nixpkgs
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Nix
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let toplevelConfig = config; inherit (lib) types; inherit (utils.systemdUtils.lib) mkPathSafeName;in{ options.systemd.services = lib.mkOption { type = types.attrsOf ( types.submodule ( { name, config, ... }: { options.confinement.enable = lib.mkOption { type = types.bool; default = false; description = '' If set, all the required runtime store paths for this service are bind-mounted into a `tmpfs`-based {manpage}`chroot(2)`. ''; };
options.confinement.fullUnit = lib.mkOption { type = types.bool; default = false; description = '' Whether to include the full closure of the systemd unit file into the chroot, instead of just the dependencies for the executables.
::: {.warning} While it may be tempting to just enable this option to make things work quickly, please be aware that this might add paths to the closure of the chroot that you didn't anticipate. It's better to use {option}`confinement.packages` to **explicitly** add additional store paths to the chroot. ::: ''; };
options.confinement.packages = lib.mkOption { type = types.listOf (types.either types.str types.package); default = [ ]; description = let mkScOption = optName: "{option}`serviceConfig.${optName}`"; in '' Additional packages or strings with context to add to the closure of the chroot. By default, this includes all the packages from the ${ lib.concatMapStringsSep ", " mkScOption [ "ExecReload" "ExecStartPost" "ExecStartPre" "ExecStop" "ExecStopPost" ] } and ${mkScOption "ExecStart"} options. If you want to have all the dependencies of this systemd unit, you can use {option}`confinement.fullUnit`.
::: {.note} The store paths listed in {option}`path` are **not** included in the closure as well as paths from other options except those listed above. ::: ''; };
options.confinement.binSh = lib.mkOption { type = types.nullOr types.path; default = toplevelConfig.environment.binsh; defaultText = lib.literalExpression "config.environment.binsh"; example = lib.literalExpression ''"''${pkgs.dash}/bin/dash"''; description = '' The program to make available as {file}`/bin/sh` inside the chroot. If this is set to `null`, no {file}`/bin/sh` is provided at all.
This is useful for some applications, which for example use the {manpage}`system(3)` library function to execute commands. ''; };
options.confinement.mode = lib.mkOption { type = types.enum [ "full-apivfs" "chroot-only" ]; default = "full-apivfs"; description = '' The value `full-apivfs` (the default) sets up private {file}`/dev`, {file}`/proc`, {file}`/sys`, {file}`/tmp` and {file}`/var/tmp` file systems in a separate user name space.
If this is set to `chroot-only`, only the file system name space is set up along with the call to {manpage}`chroot(2)`.
In all cases, unless `serviceConfig.PrivateTmp=true` is set, both {file}`/tmp` and {file}`/var/tmp` paths are added to `InaccessiblePaths=`. This is to overcome options like `DynamicUser=true` implying `PrivateTmp=true` without letting it being turned off. Beware however that giving processes the `CAP_SYS_ADMIN` and `@mount` privileges can let them undo the effects of `InaccessiblePaths=`.
::: {.note} This doesn't cover network namespaces and is solely for file system level isolation. ::: ''; };
config = let inherit (config.confinement) binSh fullUnit; wantsAPIVFS = lib.mkDefault (config.confinement.mode == "full-apivfs"); in lib.mkIf config.confinement.enable { serviceConfig = { ReadOnlyPaths = [ "+/" ]; RuntimeDirectory = [ "confinement/${mkPathSafeName name}" ]; RootDirectory = "/run/confinement/${mkPathSafeName name}"; InaccessiblePaths = [ "-+/run/confinement/${mkPathSafeName name}" ]; PrivateMounts = lib.mkDefault true;
# https://github.com/NixOS/nixpkgs/issues/14645 is a future attempt # to change some of these to default to true. # # If we run in chroot-only mode, having something like PrivateDevices # set to true by default will mount /dev within the chroot, whereas # with "chroot-only" it's expected that there are no /dev, /proc and # /sys file systems available. # # However, if this suddenly becomes true, the attack surface will # increase, so let's explicitly set these options to true/false # depending on the mode. MountAPIVFS = wantsAPIVFS; PrivateDevices = wantsAPIVFS; PrivateTmp = wantsAPIVFS; PrivateUsers = wantsAPIVFS; ProtectControlGroups = wantsAPIVFS; ProtectKernelModules = wantsAPIVFS; ProtectKernelTunables = wantsAPIVFS; }; confinement.packages = let execOpts = [ "ExecReload" "ExecStart" "ExecStartPost" "ExecStartPre" "ExecStop" "ExecStopPost" ]; execPkgs = lib.concatMap ( opt: let isSet = config.serviceConfig ? ${opt}; in lib.flatten (lib.optional isSet config.serviceConfig.${opt}) ) execOpts; unitAttrs = toplevelConfig.systemd.units."${name}.service"; allPkgs = lib.singleton (builtins.toJSON unitAttrs); unitPkgs = if fullUnit then allPkgs else execPkgs; in unitPkgs ++ lib.optional (binSh != null) binSh; }; } ) ); };
config.assertions = lib.concatLists ( lib.mapAttrsToList ( name: cfg: let whatOpt = optName: "The 'serviceConfig' option '${optName}' for" + " service '${name}' is enabled in conjunction with" + " 'confinement.enable'"; in lib.optionals cfg.confinement.enable [ { assertion = !cfg.serviceConfig.RootDirectoryStartOnly or false; message = "${whatOpt "RootDirectoryStartOnly"}, but right now systemd" + " doesn't support restricting bind-mounts to 'ExecStart'." + " Please either define a separate service or find a way to run" + " commands other than ExecStart within the chroot."; } ] ) config.systemd.services );
config.systemd.packages = lib.concatLists ( lib.mapAttrsToList ( name: cfg: let rootPaths = let contents = lib.concatStringsSep "\n" cfg.confinement.packages; in pkgs.writeText "${mkPathSafeName name}-string-contexts.txt" contents;
chrootPaths = pkgs.runCommand "${mkPathSafeName name}-chroot-paths" { closureInfo = pkgs.closureInfo { inherit rootPaths; }; serviceName = "${name}.service"; excludedPath = rootPaths; } '' mkdir -p "$out/lib/systemd/system/$serviceName.d" serviceFile="$out/lib/systemd/system/$serviceName.d/confinement.conf"
echo '[Service]' > "$serviceFile"
# /bin/sh is special here, because the option value could contain a # symlink and we need to properly resolve it. ${lib.optionalString (cfg.confinement.binSh != null) '' binsh=${lib.escapeShellArg cfg.confinement.binSh} realprog="$(readlink -e "$binsh")" echo "BindReadOnlyPaths=$realprog:/bin/sh" >> "$serviceFile" ''}
# If DynamicUser= is enabled, PrivateTmp=true is implied (and cannot be turned off). # so disable them unless PrivateTmp=true is explicitely set. ${lib.optionalString (!cfg.serviceConfig.PrivateTmp) '' echo "InaccessiblePaths=-+/tmp" >> "$serviceFile" echo "InaccessiblePaths=-+/var/tmp" >> "$serviceFile" ''}
while read storePath; do if [ -L "$storePath" ]; then # Currently, systemd can't cope with symlinks in Bind(ReadOnly)Paths, # so let's just bind-mount the target to that location. echo "BindReadOnlyPaths=$(readlink -e "$storePath"):$storePath" elif [ "$storePath" != "$excludedPath" ]; then echo "BindReadOnlyPaths=$storePath" fi done < "$closureInfo/store-paths" >> "$serviceFile" ''; in lib.optional cfg.confinement.enable chrootPaths ) config.systemd.services );}