disnix-module: split dysnomia's functionality into a separate module so that it can be used without Disnix and remove the hacky/obsolete avahi publisher

nixos/modules/module-list.nix

···
   ./services/misc/confd.nix
   ./services/misc/devmon.nix
   ./services/misc/dictd.nix
+  ./services/misc/dysnomia.nix
   ./services/misc/disnix.nix
   ./services/misc/docker-registry.nix
   ./services/misc/emby.nix

nixos/modules/services/misc/disnix.nix

···
         default = false;
         description = "Whether to enable the DisnixWebService interface running on Apache Tomcat";
       };
-
-      publishInfrastructure = {
-        enable = mkOption {
-          default = false;
-          description = "Whether to publish capabilities/properties of this machine in as attributes in the infrastructure option";
-        };
-
-        enableAuthentication = mkOption {
-          default = false;
-          description = "Whether to publish authentication credentials through the infrastructure attribute (not recommended in combination with Avahi)";
-        };
-      };
-
-      infrastructure = mkOption {
-        default = {};
-        description = "List of name value pairs containing properties for the infrastructure model";
-      };
-
-      publishAvahi = mkOption {
-        default = false;
-        description = "Whether to publish capabilities/properties as a Disnix service through Avahi";
+      
+      package = mkOption {
+        type = types.path;
+        description = "The Disnix package";
+        default = pkgs.disnix;
       };
 
     };
 
   };
-
 
   ###### implementation
 
   config = mkIf cfg.enable {
-    environment.systemPackages = [ pkgs.disnix pkgs.dysnomia ] ++ optional cfg.useWebServiceInterface pkgs.DisnixWebService;
+    dysnomia.enable = true;
+    
+    environment.systemPackages = [ pkgs.disnix ] ++ optional cfg.useWebServiceInterface pkgs.DisnixWebService;
 
     services.dbus.enable = true;
     services.dbus.packages = [ pkgs.disnix ];
 
-    services.avahi.enable = cfg.publishAvahi;
-
     services.tomcat.enable = cfg.useWebServiceInterface;
     services.tomcat.extraGroups = [ "disnix" ];
     services.tomcat.javaOpts = "${optionalString cfg.useWebServiceInterface "-Djava.library.path=${pkgs.libmatthew_java}/lib/jni"} ";
     services.tomcat.sharedLibs = optional cfg.useWebServiceInterface "${pkgs.DisnixWebService}/share/java/DisnixConnection.jar"
-                                 ++ optional cfg.useWebServiceInterface "${pkgs.dbus_java}/share/java/dbus.jar";
+      ++ optional cfg.useWebServiceInterface "${pkgs.dbus_java}/share/java/dbus.jar";
     services.tomcat.webapps = optional cfg.useWebServiceInterface pkgs.DisnixWebService;
 
     users.extraGroups = singleton
···
         gid = config.ids.gids.disnix;
       };
 
-    services.disnix.infrastructure =
-      optionalAttrs (cfg.publishInfrastructure.enable)
-      ( { hostname = config.networking.hostName;
-          #targetHost = config.deployment.targetHost;
-          system = if config.nixpkgs.system == "" then builtins.currentSystem else config.nixpkgs.system;
-
-          supportedTypes = (import "${pkgs.stdenv.mkDerivation {
-            name = "supportedtypes";
-            buildCommand = ''
-              ( echo -n "[ "
-                cd ${dysnomia}/libexec/dysnomia
-                for i in *
-                do
-                    echo -n "\"$i\" "
-                done
-                echo -n " ]") > $out
-            '';
-          }}");
-        }
-        #// optionalAttrs (cfg.useWebServiceInterface) { targetEPR = "http://${config.deployment.targetHost}:8080/DisnixWebService/services/DisnixWebService"; }
-        // optionalAttrs (config.services.httpd.enable) { documentRoot = config.services.httpd.documentRoot; }
-        // optionalAttrs (config.services.mysql.enable) { mysqlPort = config.services.mysql.port; }
-        // optionalAttrs (config.services.tomcat.enable) { tomcatPort = 8080; }
-        // optionalAttrs (config.services.svnserve.enable) { svnBaseDir = config.services.svnserve.svnBaseDir; }
-        // optionalAttrs (config.services.ejabberd.enable) { ejabberdUser = config.services.ejabberd.user; }
-        // optionalAttrs (cfg.publishInfrastructure.enableAuthentication) (
-          optionalAttrs (config.services.mysql.enable) { mysqlUsername = "root"; mysqlPassword = readFile config.services.mysql.rootPassword; })
-        )
-    ;
-
-    services.disnix.publishInfrastructure.enable = cfg.publishAvahi;
-
     systemd.services = {
       disnix = {
         description = "Disnix server";
···
 
         restartIfChanged = false;
 
-        path = [ pkgs.nix pkgs.disnix dysnomia "/run/current-system/sw" ];
+        path = [ config.nix.package cfg.package config.dysnomia.package "/run/current-system/sw" ];
 
         environment = {
           HOME = "/root";
-        };
-
-        preStart = ''
-          mkdir -p /etc/systemd-mutable/system
-          if [ ! -f /etc/systemd-mutable/system/dysnomia.target ]
-          then
-              ( echo "[Unit]"
-                echo "Description=Services that are activated and deactivated by Dysnomia"
-                echo "After=final.target"
-              ) > /etc/systemd-mutable/system/dysnomia.target
-          fi
-        '';
-
-        script = "disnix-service";
+        }
+        // (if config.environment.variables ? DYSNOMIA_CONTAINERS_PATH then { inherit (config.environment.variables) DYSNOMIA_CONTAINERS_PATH; } else {})
+        // (if config.environment.variables ? DYSNOMIA_MODULES_PATH then { inherit (config.environment.variables) DYSNOMIA_MODULES_PATH; } else {});
+        
+        serviceConfig.ExecStart = "${cfg.package}/bin/disnix-service";
       };
-    } // optionalAttrs cfg.publishAvahi {
-      disnixAvahi = {
-        description = "Disnix Avahi publisher";
-        wants = [ "avahi-daemon.service" ];
-        wantedBy = [ "multi-user.target" ];
 
-        script = ''
-          ${pkgs.avahi}/bin/avahi-publish-service disnix-${config.networking.hostName} _disnix._tcp 22 \
-            "mem=$(grep 'MemTotal:' /proc/meminfo | sed -e 's/kB//' -e 's/MemTotal://' -e 's/ //g')" \
-            ${concatMapStrings (infrastructureAttrName:
-              let infrastructureAttrValue = getAttr infrastructureAttrName (cfg.infrastructure);
-              in
-              if isInt infrastructureAttrValue then
-              ''${infrastructureAttrName}=${toString infrastructureAttrValue} \
-              ''
-              else
-              ''${infrastructureAttrName}=\"${infrastructureAttrValue}\" \
-              ''
-              ) (attrNames (cfg.infrastructure))}
-        '';
-      };
     };
   };
 }

nixos/modules/services/misc/dysnomia.nix

···
+{pkgs, lib, config, ...}:
+
+with lib;
+
+let
+  cfg = config.dysnomia;
+  
+  printProperties = properties:
+    concatMapStrings (propertyName:
+      let
+        property = properties."${propertyName}";
+      in
+      if isList property then "${propertyName}=(${lib.concatMapStrings (elem: "\"${toString elem}\" ") (properties."${propertyName}")})\n"
+      else "${propertyName}=\"${toString property}\"\n"
+    ) (builtins.attrNames properties);
+  
+  properties = pkgs.stdenv.mkDerivation {
+    name = "dysnomia-properties";
+    buildCommand = ''
+      cat > $out << "EOF"
+      ${printProperties cfg.properties}
+      EOF
+    '';
+  };
+  
+  containersDir = pkgs.stdenv.mkDerivation {
+    name = "dysnomia-containers";
+    buildCommand = ''
+      mkdir -p $out
+      cd $out
+      
+      ${concatMapStrings (containerName:
+        let
+          containerProperties = cfg.containers."${containerName}";
+        in
+        ''
+          cat > ${containerName} <<EOF
+          ${printProperties containerProperties}
+          type=${containerName}
+          EOF
+        ''
+      ) (builtins.attrNames cfg.containers)}
+    '';
+  };
+  
+  linkMutableComponents = {containerName}:
+    ''
+      mkdir ${containerName}
+      
+      ${concatMapStrings (componentName:
+        let
+          component = cfg.components."${containerName}"."${componentName}";
+        in
+        "ln -s ${component} ${containerName}/${componentName}\n"
+      ) (builtins.attrNames (cfg.components."${containerName}" or {}))}
+    '';
+  
+  componentsDir = pkgs.stdenv.mkDerivation {
+    name = "dysnomia-components";
+    buildCommand = ''
+      mkdir -p $out
+      cd $out
+      
+      ${concatMapStrings (containerName:
+        let
+          components = cfg.components."${containerName}";
+        in
+        linkMutableComponents { inherit containerName; }
+      ) (builtins.attrNames cfg.components)}
+    '';
+  };
+in
+{
+  options = {
+    dysnomia = {
+      
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Whether to enable Dysnomia";
+      };
+      
+      enableAuthentication = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Whether to publish privacy-sensitive authentication credentials";
+      };
+      
+      package = mkOption {
+        type = types.path;
+        description = "The Dysnomia package";
+      };
+      
+      properties = mkOption {
+        description = "An attribute set in which each attribute represents a machine property. Optionally, these values can be shell substitutions.";
+        default = {};
+      };
+      
+      containers = mkOption {
+        description = "An attribute set in which each key represents a container and each value an attribute set providing its configuration properties";
+        default = {};
+      };
+      
+      components = mkOption {
+        description = "An atttribute set in which each key represents a container and each value an attribute set in which each key represents a component and each value a derivation constructing its initial state";
+        default = {};
+      };
+      
+      extraContainerProperties = mkOption {
+        description = "An attribute set providing additional container settings in addition to the default properties";
+        default = {};
+      };
+      
+      extraContainerPaths = mkOption {
+        description = "A list of paths containing additional container configurations that are added to the search folders";
+        default = [];
+      };
+      
+      extraModulePaths = mkOption {
+        description = "A list of paths containing additional modules that are added to the search folders";
+        default = [];
+      };
+    };
+  };
+  
+  config = mkIf cfg.enable {
+  
+    environment.etc = {
+      "dysnomia/containers" = {
+        source = containersDir;
+      };
+      "dysnomia/components" = {
+        source = componentsDir;
+      };
+      "dysnomia/properties" = {
+        source = properties;
+      };
+    };
+    
+    environment.variables = {
+      DYSNOMIA_STATEDIR = "/var/state/dysnomia-nixos";
+      DYSNOMIA_CONTAINERS_PATH = "${lib.concatMapStrings (containerPath: "${containerPath}:") cfg.extraContainerPaths}/etc/dysnomia/containers";
+      DYSNOMIA_MODULES_PATH = "${lib.concatMapStrings (modulePath: "${modulePath}:") cfg.extraModulePaths}/etc/dysnomia/modules";
+    };
+    
+    environment.systemPackages = [ cfg.package ];
+    
+    dysnomia.package = pkgs.dysnomia.override (origArgs: {
+      enableApacheWebApplication = config.services.httpd.enable;
+      enableAxis2WebService = config.services.tomcat.axis2.enable;
+      enableEjabberdDump = config.services.ejabberd.enable;
+      enableMySQLDatabase = config.services.mysql.enable;
+      enablePostgreSQLDatabase = config.services.postgresql.enable;
+      enableSubversionRepository = config.services.svnserve.enable;
+      enableTomcatWebApplication = config.services.tomcat.enable;
+      enableMongoDatabase = config.services.mongodb.enable;
+    });
+    
+    dysnomia.properties = {
+      hostname = config.networking.hostName;
+      system = if config.nixpkgs.system == "" then builtins.currentSystem else config.nixpkgs.system;
+
+      supportedTypes = (import "${pkgs.stdenv.mkDerivation {
+        name = "supportedtypes";
+        buildCommand = ''
+          ( echo -n "[ "
+            cd ${cfg.package}/libexec/dysnomia
+            for i in *
+            do
+                echo -n "\"$i\" "
+            done
+            echo -n " ]") > $out
+        '';
+      }}");
+    };
+    
+    dysnomia.containers = lib.recursiveUpdate ({
+      process = {};
+      wrapper = {};
+    }
+    // lib.optionalAttrs (config.services.httpd.enable) { apache-webapplication = {
+      documentRoot = config.services.httpd.documentRoot;
+    }; }
+    // lib.optionalAttrs (config.services.tomcat.axis2.enable) { axis2-webservice = {}; }
+    // lib.optionalAttrs (config.services.ejabberd.enable) { ejabberd-dump = {
+      ejabberdUser = config.services.ejabberd.user;
+    }; }
+    // lib.optionalAttrs (config.services.mysql.enable) { mysql-database = {
+        mysqlPort = config.services.mysql.port;
+      } // lib.optionalAttrs cfg.enableAuthentication {
+        mysqlUsername = "root";
+        mysqlPassword = builtins.readFile (config.services.mysql.rootPassword);
+      };
+    }
+    // lib.optionalAttrs (config.services.postgresql.enable && cfg.enableAuthentication) { postgresql-database = {
+      postgresqlUsername = "root";
+    }; }
+    // lib.optionalAttrs (config.services.tomcat.enable) { tomcat-webapplication = {
+      tomcatPort = 8080;
+    }; }
+    // lib.optionalAttrs (config.services.mongodb.enable) { mongo-database = {}; }
+    // lib.optionalAttrs (config.services.svnserve.enable) { subversion-repository = {
+      svnBaseDir = config.services.svnserve.svnBaseDir;
+    }; }) cfg.extraContainerProperties;
+
+    system.activationScripts.dysnomia = ''
+      mkdir -p /etc/systemd-mutable/system
+      if [ ! -f /etc/systemd-mutable/system/dysnomia.target ]
+      then
+          ( echo "[Unit]"
+            echo "Description=Services that are activated and deactivated by Dysnomia"
+            echo "After=final.target"
+          ) > /etc/systemd-mutable/system/dysnomia.target
+      fi
+    '';
+  };
+}