1 files changed, 80 insertions, 0 deletions
diff --git a/krebs/3modules/exim.nix b/krebs/3modules/exim.nix
new file mode 100644
index 000000000..7b18c72c1
--- /dev/null
+++ b/krebs/3modules/exim.nix
@@ -0,0 +1,80 @@
+{ config, lib, pkgs, ... }: with config.krebs.lib; let
+  cfg = config.krebs.exim;
+in {
+  options.krebs.exim = {
+    enable = mkEnableOption "krebs.exim";
+    config = mkOption {
+      type = types.str;
+      default = "";
+      description = ''
+        Verbatim Exim configuration.  This should not contain exim_user,
+        exim_group, exim_path, or spool_directory.
+      '';
+    };
+    user = mkOption {
+      type = types.user;
+      default = {
+        name = "exim";
+        home = "/var/spool/exim";
+      };
+      description = ''
+        User to use when no root privileges are required.
+        In particular, this applies when receiving messages and when doing
+        remote deliveries.  (Local deliveries run as various non-root users,
+        typically as the owner of a local mailbox.) Specifying this value
+        as root is not supported.
+      '';
+    };
+    group = mkOption {
+      type = types.group;
+      default = {
+        name = "exim";
+      };
+      description = ''
+        Group to use when no root privileges are required.
+      '';
+    };
+  };
+  config = lib.mkIf cfg.enable {
+    environment = {
+      etc."exim.conf".source = pkgs.writeEximConfig "exim.conf" ''
+        exim_user = ${cfg.user.name}
+        exim_group = ${cfg.group.name}
+        exim_path = /var/setuid-wrappers/exim
+        spool_directory = ${cfg.user.home}
+        ${cfg.config}
+      '';
+      systemPackages = [ pkgs.exim ];
+    };
+    krebs.setuid = {
+      exim = {
+        filename = "${pkgs.exim}/bin/exim";
+        mode = "4111";
+      };
+      sendmail = {
+        filename = "${pkgs.exim}/bin/exim";
+        mode = "4111";
+      };
+    };
+    systemd.services.exim = {
+      restartTriggers = [
+        config.environment.etc."exim.conf".source
+      ];
+      serviceConfig = {
+        ExecStart = "${pkgs.exim}/bin/exim -bdf -q30m";
+        ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
+      };
+      wantedBy = [ "multi-user.target" ];
+    };
+    users = {
+      groups.${cfg.group.name} = {
+        inherit (cfg.group) name gid;
+      };
+      users.${cfg.user.name} = {
+        inherit (cfg.user) home name uid;
+        createHome = true;
+        group = cfg.group.name;
+      };
+    };
+  };
+}