phoebus-scan-server: nixos module

Closes epics-extensions#74

nixos/module-list.nix

@@ -3,6 +3,7 @@
   ./modules/ca-gateway.nix
   ./modules/phoebus/alarm-logger.nix
   ./modules/phoebus/alarm-server.nix
+  ./modules/phoebus/scan-server.nix
   ./modules/phoebus/olog.nix
   ./modules/phoebus/save-and-restore.nix
 ]

nixos/modules/phoebus/scan-server.nix

@@ -0,0 +1,85 @@
+{
+  config,
+  epnixLib,
+  lib,
+  pkgs,
+  ...
+}: let
+  cfg = config.services.phoebus-scan-server;
+  buildConfig = settings: with lib; concatLines (mapAttrsToList (k: v: "<${k}>${builtins.toString v}</${k}>") settings);
+  mainConfig = buildConfig cfg.settings;
+  pvConfig = with lib; concatLines (map (pv: "<pv>${buildConfig pv}</pv>") cfg.pvs);
+
+  rawConfigFile = pkgs.writeText "scan_config_raw.xml" ''
+    <?xml version="1.0"?>
+    <!-- Generated by NixOS/EPNix (services.phoebus-scan-server) -->
+
+    <scan_config>
+        <!-- Set by services.phoebus-scan-server.settings: -->
+        ${mainConfig}
+
+        <!-- Set by services.phoebus-scan-server.pvs: -->
+        ${pvConfig}
+    </scan_config>
+  '';
+
+  configFile = pkgs.runCommand "scan_config.xml" {nativeBuildInputs = [pkgs.libxml2];} ''
+    xmllint --format ${rawConfigFile} > $out
+  '';
+in {
+  options.services.phoebus-scan-server = {
+    enable = lib.mkEnableOption "the Phoebus scan server";
+
+    settings = lib.mkOption {
+      description = ''
+        Configuration for Phoebus scan server
+
+        Will be converted to an XML file
+
+        PVs are not specified here but in services.phoebus-scan-server.pvs
+      '';
+
+      default = {};
+      type = lib.types.submodule {
+        freeformType = with lib.types; attrsOf (oneOf [str int]);
+
+        options.port = lib.mkOption {
+          type = lib.types.port;
+
+          default = 4810;
+        };
+      };
+    };
+
+    pvs = lib.mkOption {
+      default = [];
+      type = lib.types.listOf (lib.types.submodule {
+        freeformType = with lib.types; attrsOf str;
+      });
+    };
+
+    openFirewall = lib.mkOption {
+      description = ''
+        Open the firewall for the Phoebus Scan Server.
+
+        Warning: this opens the firewall on all network interfaces.
+      '';
+      type = lib.types.bool;
+      default = false;
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.services.phoebus-scan-server = {
+      description = "Phoebus Scan Server";
+
+      wantedBy = ["multi-user.target"];
+
+      serviceConfig = {
+        ExecStart = "${lib.getExe pkgs.epnix.phoebus-scan-server} -config ${configFile} -noshell";
+      };
+    };
+
+    networking.firewall.allowedTCPPorts = lib.mkIf cfg.openFirewall [cfg.settings.port];
+  };
+}

nixos/tests/all-tests.nix

@@ -20,4 +20,5 @@ in {
   phoebus-alarm = handleTest ./phoebus/alarm.nix {};
   phoebus-olog = handleTest ./phoebus/olog.nix {};
   phoebus-save-and-restore = handleTest ./phoebus/save-and-restore.nix {};
+  phoebus-scan-server = handleTest ./phoebus/scan-server.nix {};
 }

nixos/tests/phoebus/scan-server.nix

@@ -0,0 +1,29 @@
+{
+  lib,
+  epnixLib,
+  ...
+}: {
+  name = "phoebus-scan-server-simple-check";
+  meta.maintainers = with epnixLib.maintainers; [synthetica];
+
+  nodes = {
+    server = {
+      services.phoebus-scan-server = {
+        enable = true;
+        openFirewall = true;
+      };
+    };
+
+    client = {};
+  };
+
+  testScript = ''
+    start_all()
+    server.wait_for_unit('phoebus-scan-server.service')
+    print(server.succeed('systemctl status phoebus-scan-server'))
+    server.wait_for_open_port(4810)
+    info = client.succeed('curl http://server:4810/server/info')
+    print('Server claims following info:')
+    print(info)
+  '';
+}