ioc/nixos-integration: support multiple systemd services

ioc/modules/nixos-integration.nix

@@ -5,96 +5,115 @@
   pkgs,
   ...
 }: let
-  cfg = config.epnix.nixos;
+  globalConfig = config;
 
   iocTop = "${config.epnix.outputs.build}";
 in {
   options.epnix.nixos = {
-    service = {
-      app = lib.mkOption {
-        type = lib.types.str;
-        example = "my_exec";
-        description = ''
-          Name of the app to start the IOC with.
-        '';
+    services = lib.mkOption {
+      description = ''
+        Services for which to create a systemd service config.
+      '';
+      example = {
+        ioc = {
+          app = "examples";
+          ioc = "iocExamples";
+        };
       };
+      type = lib.types.attrsOf (lib.types.submodule ({config, ...}: {
+        options = {
+          app = lib.mkOption {
+            type = lib.types.str;
+            example = "my_exec";
+            description = ''
+              Name of the app to start the IOC with.
+            '';
+          };
 
-      ioc = lib.mkOption {
-        type = lib.types.str;
-        example = "iocMyDevice";
-        description = ''
-          Name of the directory under `iocBoot` containing the start commands.
-        '';
-      };
+          ioc = lib.mkOption {
+            type = lib.types.str;
+            example = "iocMyDevice";
+            description = ''
+              Name of the directory under `iocBoot` containing the start commands.
+            '';
+          };
 
-      startCommandsFile = lib.mkOption {
-        default = "st.cmd";
-        example = "other_st.cmd";
-        type = lib.types.str;
-        description = ''
-          Name of the file containing the EPICS start commands.
-        '';
-      };
+          startCommandsFile = lib.mkOption {
+            default = "st.cmd";
+            example = "other_st.cmd";
+            type = lib.types.str;
+            description = ''
+              Name of the file containing the EPICS start commands.
+            '';
+          };
 
-      config = lib.mkOption {
-        type = lib.types.attrs;
-        readOnly = true;
-        description = ''
-          Resulting configuration for the systemd service.
-        '';
-      };
+          config = lib.mkOption {
+            type = lib.types.attrs;
+            readOnly = true;
+            description = ''
+              Resulting configuration for the systemd service.
+            '';
+          };
 
-      procServ = {
-        port = lib.mkOption {
-          default = 2000;
-          type = lib.types.port;
-          description = ''
-            Port where the procServ utility will listen.
-          '';
-        };
+          procServ = {
+            port = lib.mkOption {
+              default = 2000;
+              type = lib.types.port;
+              description = ''
+                Port where the procServ utility will listen.
+              '';
+            };
 
-        options = lib.mkOption {
-          default = {};
-          example = {
-            allow = true;
-            info-file = "/var/run/ioc/procServ_info";
+            options = lib.mkOption {
+              default = {};
+              example = {
+                allow = true;
+                info-file = "/var/run/ioc/procServ_info";
+              };
+              type = with lib.types; attrsOf (oneOf [str int bool (listOf str)]);
+              description = ''
+                Extra command-line options to pass to procServ.
+
+                Note: using `lib.mkForce` will override the default options needed
+                for the systemd service to work. If you wish to do this, you will
+                need to specify needed arguments like `foreground` and `chdir`.
+              '';
+            };
           };
-          type = with lib.types; attrsOf (oneOf [str int bool (listOf str)]);
-          description = ''
-            Extra command-line options to pass to procServ.
+        };
 
-            Note: using `lib.mkForce` will override the default options needed
-            for the systemd service to work. If you wish to do this, you will
-            need to specify needed arguments like `foreground` and `chdir`.
-          '';
+        config.procServ.options = {
+          foreground = true;
+          oneshot = true;
+          logfile = "-";
+          holdoff = 0;
+          chdir = "${iocTop}/iocBoot/${config.ioc}";
         };
-      };
-    };
-  };
 
-  config.epnix.nixos.service.procServ.options = {
-    foreground = true;
-    oneshot = true;
-    logfile = "-";
-    chdir = "${iocTop}/iocBoot/${cfg.service.ioc}";
-  };
+        config.config = {
+          wantedBy = ["multi-user.target"];
 
-  config.epnix.nixos.service.config = {
-    wantedBy = ["multi-user.target"];
-    after = ["network.target"];
+          # When initializing the IOC, PV Access looks for network interfaces that
+          # have IP addresses. "network.target" may be too early, especially for
+          # systems with DHCP.
+          wants = ["network-online.target"];
+          after = ["network-online.target"];
 
-    description = "EPICS IOC ${config.epnix.meta.name}";
+          description = "EPICS IOC ${globalConfig.epnix.meta.name}";
 
-    serviceConfig = {
-      ExecStart = let
-        procServ = "${pkgs.epnix.procServ}/bin/procServ";
-        arch = epnix.lib.toEpicsArch config.epnix.outputs.build.stdenv.hostPlatform;
-      in ''
-        ${procServ} ${lib.cli.toGNUCommandLineShell {} cfg.service.procServ.options} \
-        ${toString cfg.service.procServ.port} \
-        ${iocTop}/bin/${arch}/${cfg.service.app} ${cfg.service.startCommandsFile}
-      '';
-      Restart = "on-failure";
+          serviceConfig = {
+            ExecStart = let
+              procServ = "${pkgs.epnix.procServ}/bin/procServ";
+              arch = epnix.lib.toEpicsArch globalConfig.epnix.outputs.build.stdenv.hostPlatform;
+            in ''
+              ${procServ} ${lib.cli.toGNUCommandLineShell {} config.procServ.options} \
+              ${toString config.procServ.port} \
+              ${iocTop}/bin/${arch}/${config.app} ${config.startCommandsFile}
+            '';
+            Restart = "on-failure";
+          };
+        };
+      }));
     };
   };
 }

ioc/tests/support/StreamDevice/simple/default.nix

@@ -11,7 +11,7 @@
     epnixConfig.imports = [./top/epnix.nix];
   };
 
-  service = result.config.epnix.nixos.service.config;
+  service = result.config.epnix.nixos.services.ioc.config;
 
   ioc = result.outputs.build;
 in

ioc/tests/support/StreamDevice/simple/top/epnix.nix

@@ -5,7 +5,9 @@
 
     support.modules = with pkgs.epnix.support; [StreamDevice epics-systemd];
 
-    nixos.service.app = "simple";
-    nixos.service.ioc = "iocsimple";
+    nixos.services.ioc = {
+      app = "simple";
+      ioc = "iocsimple";
+    };
   };
 }

ioc/tests/support/autosave/simple/autosaveSimpleTestTop/epnix.nix

@@ -5,7 +5,9 @@
 
     support.modules = with pkgs.epnix.support; [autosave];
 
-    nixos.service.app = "simple";
-    nixos.service.ioc = "iocSimple";
+    nixos.services.ioc = {
+      app = "simple";
+      ioc = "iocSimple";
+    };
   };
 }

ioc/tests/support/autosave/simple/default.nix

@@ -7,7 +7,7 @@
     epnixConfig.imports = [./autosaveSimpleTestTop/epnix.nix];
   };
 
-  service = result.config.epnix.nixos.service.config;
+  service = result.config.epnix.nixos.services.ioc.config;
 
   ioc = result.outputs.build;
 in

ioc/tests/support/seq/simple/default.nix

@@ -7,7 +7,7 @@
     epnixConfig.imports = [./top/epnix.nix];
   };
 
-  service = result.config.epnix.nixos.service.config;
+  service = result.config.epnix.nixos.services.ioc.config;
 
   ioc = result.outputs.build;
 in

ioc/tests/support/seq/simple/top/epnix.nix

@@ -5,7 +5,9 @@
 
     support.modules = with pkgs.epnix.support; [seq];
 
-    nixos.service.app = "simple";
-    nixos.service.ioc = "iocsimple";
+    nixos.services.ioc = {
+      app = "simple";
+      ioc = "iocsimple";
+    };
   };
 }