nixos/traefik create service

nixos/modules/module-list.nix

@@ -621,6 +621,7 @@
   ./services/web-servers/phpfpm/default.nix
   ./services/web-servers/shellinabox.nix
   ./services/web-servers/tomcat.nix
+  ./services/web-servers/traefik.nix
   ./services/web-servers/uwsgi.nix
   ./services/web-servers/varnish/default.nix
   ./services/web-servers/winstone.nix

nixos/modules/services/web-servers/traefik.nix

@@ -0,0 +1,114 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.traefik;
+  configFile =
+    if cfg.configFile == null then
+      pkgs.runCommand "config.toml" {
+        buildInputs = [ pkgs.remarshal ];
+      } ''
+        remarshal -if json -of toml \
+          < ${pkgs.writeText "config.json" (builtins.toJSON cfg.configOptions)} \
+          > $out
+      ''
+    else cfg.configFile;
+
+in {
+  options.services.traefik = {
+    enable = mkEnableOption "Traefik web server";
+
+    configFile = mkOption {
+      default = null;
+      example = /path/to/config.toml;
+      type = types.nullOr types.path;
+      description = ''
+        Path to verbatim traefik.toml to use.
+        (Using that option has precedence over <literal>configOptions</literal>)
+      '';
+    };
+
+    configOptions = mkOption {
+      description = ''
+        Config for Traefik.
+      '';
+      type = types.attrs;
+      default = {
+        defaultEntryPoints = ["http"];
+        entryPoints.http.address = ":80";
+      };
+      example = {
+        defaultEntrypoints = [ "http" ];
+        web.address = ":8080";
+        entryPoints.http.address = ":80";
+
+        file = {};
+        frontends = {
+          frontend1 = {
+            backend = "backend1";
+            routes.test_1.rule = "Host:localhost";
+          };
+        };
+        backends.backend1 = {
+          servers.server1.url = "http://localhost:8000";
+        };
+      };
+    };
+
+    dataDir = mkOption {
+      default = "/var/lib/traefik";
+      type = types.path;
+      description = ''
+      Location for any persistent data traefik creates, ie. acme
+      '';
+    };
+
+    package = mkOption {
+      default = pkgs.traefik;
+      defaultText = "pkgs.traefik";
+      type = types.package;
+      description = "Traefik package to use.";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.traefik = {
+      description = "Traefik web server";
+      after = [ "network-online.target" ];
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = {
+        PermissionsStartOnly = true;
+        ExecStart = ''${cfg.package.bin}/bin/traefik --configfile=${configFile}'';
+        ExecStartPre = [
+          ''${pkgs.coreutils}/bin/mkdir -p "${cfg.dataDir}"''
+          ''${pkgs.coreutils}/bin/install -d -m700 --owner traefik --group traefik "${cfg.dataDir}"''
+        ];
+        Type = "simple";
+        User = "traefik";
+        Group = "traefik";
+        Restart = "on-failure";
+        StartLimitInterval = 86400;
+        StartLimitBurst = 5;
+        AmbientCapabilities = "cap_net_bind_service";
+        CapabilityBoundingSet = "cap_net_bind_service";
+        NoNewPrivileges = true;
+        LimitNPROC = 64;
+        LimitNOFILE = 1048576;
+        PrivateTmp = true;
+        PrivateDevices = true;
+        ProtectHome = true;
+        ProtectSystem = "full";
+        ReadWriteDirectories = cfg.dataDir;
+      };
+    };
+
+    users.extraUsers.traefik = {
+      group = "traefik";
+      home = cfg.dataDir;
+      createHome = true;
+    };
+
+    users.extraGroups.traefik = {};
+  };
+}