nixseparatedebuginfod: add module and nixos test

nixos/modules/module-list.nix

@@ -489,6 +489,7 @@
   ./services/development/jupyterhub/default.nix
   ./services/development/livebook.nix
   ./services/development/lorri.nix
+  ./services/development/nixseparatedebuginfod.nix
   ./services/development/rstudio-server/default.nix
   ./services/development/zammad.nix
   ./services/display-managers/greetd.nix

nixos/modules/services/development/nixseparatedebuginfod.nix

@@ -0,0 +1,105 @@
+{ pkgs, lib, config, ... }:
+let
+  cfg = config.services.nixseparatedebuginfod;
+  url = "127.0.0.1:${toString cfg.port}";
+in
+{
+  options = {
+    services.nixseparatedebuginfod = {
+      enable = lib.mkEnableOption "separatedebuginfod, a debuginfod server providing source and debuginfo for nix packages";
+      port = lib.mkOption {
+        description = "port to listen";
+        default = 1949;
+        type = lib.types.port;
+      };
+      nixPackage = lib.mkOption {
+        type = lib.types.package;
+        default = pkgs.nix;
+        defaultText = lib.literalExpression "pkgs.nix";
+        description = ''
+          The version of nix that nixseparatedebuginfod should use as client for the nix daemon. It is strongly advised to use nix version >= 2.18, otherwise some debug info may go missing.
+        '';
+      };
+      allowOldNix = lib.mkOption {
+        type = lib.types.bool;
+        default = false;
+        description = ''
+          Do not fail evaluation when {option}`services.nixseparatedebuginfod.nixPackage` is older than nix 2.18.
+        '';
+      };
+    };
+  };
+  config = lib.mkIf cfg.enable {
+    assertions = [ {
+      assertion = cfg.allowOldNix || (lib.versionAtLeast cfg.nixPackage.version "2.18");
+      message = "nixseparatedebuginfod works better when `services.nixseparatedebuginfod.nixPackage` is set to nix >= 2.18 (instead of ${cfg.nixPackage.name}). Set `services.nixseparatedebuginfod.allowOldNix` to bypass.";
+    } ];
+
+    systemd.services.nixseparatedebuginfod = {
+      wantedBy = [ "multi-user.target" ];
+      wants = [ "nix-daemon.service" ];
+      after = [ "nix-daemon.service" ];
+      path = [ cfg.nixPackage ];
+      serviceConfig = {
+        ExecStart = [ "${pkgs.nixseparatedebuginfod}/bin/nixseparatedebuginfod -l ${url}" ];
+        Restart = "on-failure";
+        CacheDirectory = "nixseparatedebuginfod";
+        # nix does not like DynamicUsers in allowed-users
+        User = "nixseparatedebuginfod";
+        Group = "nixseparatedebuginfod";
+
+        # hardening
+        # Filesystem stuff
+        ProtectSystem = "strict"; # Prevent writing to most of /
+        ProtectHome = true; # Prevent accessing /home and /root
+        PrivateTmp = true; # Give an own directory under /tmp
+        PrivateDevices = true; # Deny access to most of /dev
+        ProtectKernelTunables = true; # Protect some parts of /sys
+        ProtectControlGroups = true; # Remount cgroups read-only
+        RestrictSUIDSGID = true; # Prevent creating SETUID/SETGID files
+        PrivateMounts = true; # Give an own mount namespace
+        RemoveIPC = true;
+        UMask = "0077";
+
+        # Capabilities
+        CapabilityBoundingSet = ""; # Allow no capabilities at all
+        NoNewPrivileges = true; # Disallow getting more capabilities. This is also implied by other options.
+
+        # Kernel stuff
+        ProtectKernelModules = true; # Prevent loading of kernel modules
+        SystemCallArchitectures = "native"; # Usually no need to disable this
+        ProtectKernelLogs = true; # Prevent access to kernel logs
+        ProtectClock = true; # Prevent setting the RTC
+
+        # Networking
+        RestrictAddressFamilies = "AF_UNIX AF_INET AF_INET6";
+
+        # Misc
+        LockPersonality = true; # Prevent change of the personality
+        ProtectHostname = true; # Give an own UTS namespace
+        RestrictRealtime = true; # Prevent switching to RT scheduling
+        MemoryDenyWriteExecute = true; # Maybe disable this for interpreters like python
+        RestrictNamespaces = true;
+      };
+    };
+
+    users.users.nixseparatedebuginfod = {
+      isSystemUser = true;
+      group = "nixseparatedebuginfod";
+    };
+
+    users.groups.nixseparatedebuginfod = { };
+
+    nix.settings.extra-allowed-users = [ "nixseparatedebuginfod" ];
+
+    environment.variables.DEBUGINFOD_URLS = "http://${url}";
+
+    environment.systemPackages = [
+      # valgrind support requires debuginfod-find on PATH
+      (lib.getBin pkgs.elfutils)
+    ];
+
+    environment.etc."gdb/gdbinit.d/nixseparatedebuginfod.gdb".text = "set debuginfod enabled on";
+
+  };
+}

nixos/tests/all-tests.nix

@@ -592,6 +592,7 @@ in {
   nixos-rebuild-install-bootloader = handleTestOn ["x86_64-linux"] ./nixos-rebuild-install-bootloader.nix {};
   nixos-rebuild-specialisations = handleTestOn ["x86_64-linux"] ./nixos-rebuild-specialisations.nix {};
   nixpkgs = pkgs.callPackage ../modules/misc/nixpkgs/test.nix { inherit evalMinimalConfig; };
+  nixseparatedebuginfod = handleTest ./nixseparatedebuginfod.nix {};
   node-red = handleTest ./node-red.nix {};
   nomad = handleTest ./nomad.nix {};
   non-default-filesystems = handleTest ./non-default-filesystems.nix {};

nixos/tests/nixseparatedebuginfod.nix

@@ -0,0 +1,80 @@
+import ./make-test-python.nix ({ pkgs, lib, ... }:
+let
+  secret-key = "key-name:/COlMSRbehSh6YSruJWjL+R0JXQUKuPEn96fIb+pLokEJUjcK/2Gv8Ai96D7JGay5gDeUTx5wdpPgNvum9YtwA==";
+  public-key = "key-name:BCVI3Cv9hr/AIveg+yRmsuYA3lE8ecHaT4Db7pvWLcA=";
+in
+{
+  name = "nixseparatedebuginfod";
+  /* A binary cache with debug info and source for nix */
+  nodes.cache = { pkgs, ... }: {
+    services.nix-serve = {
+      enable = true;
+      secretKeyFile = builtins.toFile "secret-key" secret-key;
+      openFirewall = true;
+    };
+    system.extraDependencies = [
+      pkgs.nix.debug
+      pkgs.nix.src
+      pkgs.sl
+    ];
+  };
+  /* the machine where we need the debuginfo */
+  nodes.machine = {
+    imports = [
+      ../modules/installer/cd-dvd/channel.nix
+    ];
+    services.nixseparatedebuginfod.enable = true;
+    nix.settings = {
+      substituters = lib.mkForce [ "http://cache:5000" ];
+      trusted-public-keys = [ public-key ];
+    };
+    environment.systemPackages = [
+      pkgs.valgrind
+      pkgs.gdb
+      (pkgs.writeShellScriptBin "wait_for_indexation" ''
+        set -x
+        while debuginfod-find debuginfo /run/current-system/sw/bin/nix |& grep 'File too large'; do
+          sleep 1;
+        done
+      '')
+    ];
+  };
+  testScript = ''
+    start_all()
+    cache.wait_for_unit("nix-serve.service")
+    cache.wait_for_open_port(5000)
+    machine.wait_for_unit("nixseparatedebuginfod.service")
+    machine.wait_for_open_port(1949)
+
+    with subtest("show the config to debug the test"):
+      machine.succeed("nix --extra-experimental-features nix-command show-config |& logger")
+      machine.succeed("cat /etc/nix/nix.conf |& logger")
+    with subtest("check that the binary cache works"):
+      machine.succeed("nix-store -r ${pkgs.sl}")
+
+    # nixseparatedebuginfod needs .drv to associate executable -> source
+    # on regular systems this would be provided by nixos-rebuild
+    machine.succeed("nix-instantiate '<nixpkgs>' -A nix")
+
+    machine.succeed("timeout 600 wait_for_indexation")
+
+    # test debuginfod-find
+    machine.succeed("debuginfod-find debuginfo /run/current-system/sw/bin/nix")
+
+    # test that gdb can fetch source
+    out = machine.succeed("gdb /run/current-system/sw/bin/nix --batch -x ${builtins.toFile "commands" ''
+    start
+    l
+    ''}")
+    print(out)
+    assert 'int main(' in out
+
+    # test that valgrind can display location information
+    # this relies on the fact that valgrind complains about nix
+    # libgc helps in this regard, and we also ask valgrind to show leak kinds
+    # which are usually false positives.
+    out = machine.succeed("valgrind --leak-check=full --show-leak-kinds=all nix-env --version 2>&1")
+    print(out)
+    assert 'main.cc' in out
+  '';
+})

pkgs/by-name/ni/nixseparatedebuginfod/package.nix

@@ -5,6 +5,7 @@
 , openssl
 , sqlite
 , pkg-config
+, nixosTests
 }:
 
 rustPlatform.buildRustPackage rec {
@@ -31,6 +32,12 @@ rustPlatform.buildRustPackage rec {
 
   nativeBuildInputs = [ pkg-config ];
 
+  passthru = {
+    tests = {
+      inherit (nixosTests) nixseparatedebuginfod;
+    };
+  };
+
   meta = with lib; {
     description = "Downloads and provides debug symbols and source code for nix derivations to gdb and other debuginfod-capable debuggers as needed";
     homepage = "https://github.com/symphorien/nixseparatedebuginfod";