1 files changed, 127 insertions, 0 deletions
diff --git a/nixos/modules/testing/service-runner.nix b/nixos/modules/testing/service-runner.nix
new file mode 100644
index 00000000000..9060be3cca1
--- /dev/null
+++ b/nixos/modules/testing/service-runner.nix
@@ -0,0 +1,127 @@
+{ lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  makeScript = name: service: pkgs.writeScript "${name}-runner"
+    ''
+      #! ${pkgs.perl.withPackages (p: [ p.FileSlurp ])}/bin/perl -w
+
+      use File::Slurp;
+
+      sub run {
+          my ($cmd) = @_;
+          my @args = ();
+          while ($cmd =~ /([^ \t\n']+)|(\'([^'])\')\s*/g) {
+            push @args, $1;
+          }
+          my $prog;
+          if (substr($args[0], 0, 1) eq "@") {
+              $prog = substr($args[0], 1);
+              shift @args;
+          } else {
+              $prog = $args[0];
+          }
+          my $pid = fork;
+          if ($pid == 0) {
+              setpgrp; # don't receive SIGINT etc. from terminal
+              exec { $prog } @args;
+              die "failed to exec $prog\n";
+          } elsif (!defined $pid) {
+              die "failed to fork: $!\n";
+          }
+          return $pid;
+      };
+
+      sub run_wait {
+          my ($cmd) = @_;
+          my $pid = run $cmd;
+          die if waitpid($pid, 0) != $pid;
+          return $?;
+      };
+
+      # Set the environment.  FIXME: escaping.
+      foreach my $key (keys %ENV) {
+          next if $key eq 'LOCALE_ARCHIVE';
+          delete $ENV{$key};
+      }
+      ${concatStrings (mapAttrsToList (n: v: ''
+        $ENV{'${n}'} = '${v}';
+      '') service.environment)}
+
+      # Run the ExecStartPre program.  FIXME: this could be a list.
+      my $preStart = <<END_CMD;
+      ${concatStringsSep "\n" (service.serviceConfig.ExecStartPre or [])}
+      END_CMD
+      if (defined $preStart && $preStart ne "\n") {
+          print STDERR "running ExecStartPre: $preStart\n";
+          my $res = run_wait $preStart;
+          die "$0: ExecStartPre failed with status $res\n" if $res;
+      };
+
+      # Run the ExecStart program.
+      my $cmd = <<END_CMD;
+      ${service.serviceConfig.ExecStart}
+      END_CMD
+
+      print STDERR "running ExecStart: $cmd\n";
+      my $mainPid = run $cmd;
+      $ENV{'MAINPID'} = $mainPid;
+
+      # Catch SIGINT, propagate to the main program.
+      sub intHandler {
+          print STDERR "got SIGINT, stopping service...\n";
+          kill 'INT', $mainPid;
+      };
+      $SIG{'INT'} = \&intHandler;
+      $SIG{'QUIT'} = \&intHandler;
+
+      # Run the ExecStartPost program.
+      my $postStart = <<END_CMD;
+      ${concatStringsSep "\n" (service.serviceConfig.ExecStartPost or [])}
+      END_CMD
+      if (defined $postStart && $postStart ne "\n") {
+          print STDERR "running ExecStartPost: $postStart\n";
+          my $res = run_wait $postStart;
+          die "$0: ExecStartPost failed with status $res\n" if $res;
+      }
+
+      # Wait for the main program to exit.
+      die if waitpid($mainPid, 0) != $mainPid;
+      my $mainRes = $?;
+
+      # Run the ExecStopPost program.
+      my $postStop = <<END_CMD;
+      ${service.serviceConfig.ExecStopPost or ""}
+      END_CMD
+      if (defined $postStop && $postStop ne "\n") {
+          print STDERR "running ExecStopPost: $postStop\n";
+          my $res = run_wait $postStop;
+          die "$0: ExecStopPost failed with status $res\n" if $res;
+      }
+
+      exit($mainRes & 127 ? 255 : $mainRes << 8);
+    '';
+
+  opts = { config, name, ... }: {
+    options.runner = mkOption {
+    internal = true;
+    description = ''
+        A script that runs the service outside of systemd,
+        useful for testing or for using NixOS services outside
+        of NixOS.
+    '';
+    };
+    config.runner = makeScript name config;
+  };
+
+in
+
+{
+  options = {
+    systemd.services = mkOption {
+      type = with types; attrsOf (submodule opts);
+    };
+  };
+}