nix/lib/default.nix in confctl-1.0.0 vs nix/lib/default.nix in confctl-2.0.0

@@ -1,31 +1,76 @@
 { confDir, coreLib, corePkgs }:
 with coreLib;
 let
-  machine = import ./machine { inherit confDir corePkgs coreLib findConfig; };
+  machine = import ./machine { inherit confDir corePkgs coreLib findMetaConfig; };
 
-  findConfig =
+  findMetaConfig =
     { cluster, name }:
     cluster.${name};
 
   makeMachine =
-    { name, config }:
-    {
-      inherit name config;
-      build.toplevel = buildConfig { inherit name config; };
+    { name, metaConfig, carrier ? null, alias ? null, clusterName ? null, extraModules ? [], buildAttribute ? null }:
+    let
+      ensuredClusterName = if isNull clusterName then name else clusterName;
+    in {
+      inherit name alias metaConfig carrier extraModules;
+      clusterName = ensuredClusterName;
+
+      build = {
+        attribute = if isNull buildAttribute then metaConfig.buildAttribute else buildAttribute;
+        toplevel = buildConfig { name = ensuredClusterName; inherit metaConfig; };
+      };
     };
 
   buildConfig =
-    { name, config }:
-    if !config.managed then
+    { name, metaConfig }:
+    if !metaConfig.managed then
       null
-    else if config.spin == "nixos" then
-      machine.nixos { inherit name config; }
-    else if config.spin == "vpsadminos" then
-      machine.vpsadminos { inherit name config; }
+    else if metaConfig.spin == "nixos" then
+      machine.nixos { inherit name metaConfig; }
+    else if metaConfig.spin == "vpsadminos" then
+      machine.vpsadminos { inherit name metaConfig; }
     else
       null;
+
+  expandCarriers = machineAttrs: flatten (mapAttrsToList (name: m:
+    if m.metaConfig.carrier.enable then
+      [ m ] ++ (expandCarrier machineAttrs m)
+    else
+      m
+  ) machineAttrs);
+
+  expandCarrier = machineAttrs: carrierMachine: map (cm:
+    makeMachine {
+      name = "${carrierMachine.name}#${if isNull cm.alias then cm.machine else cm.alias}";
+      alias = cm.alias;
+      clusterName = cm.machine;
+      carrier = carrierMachine.name;
+      extraModules = cm.extraModules;
+      buildAttribute = cm.buildAttribute;
+      metaConfig = coreLib.updateManyAttrsByPath ([
+        {
+          path = [ "labels" ];
+          update = old: old // cm.labels;
+        }
+        {
+          path = [ "tags" ];
+          update = old: old ++ cm.tags;
+        }
+      ] ++ (generationUpdates cm)) machineAttrs.${cm.machine}.metaConfig;
+    }
+  ) carrierMachine.metaConfig.carrier.machines;
+
+  generationUpdates = cm:
+    flatten (map (generations:
+      map (attr: {
+        path = [ generations attr ];
+        update = old:
+          let v = cm.${generations}.${attr};
+          in if isNull v then old else v;
+      }) [ "min" "max" "maxAge" ]
+    ) [ "buildGenerations" "hostGenerations" ]);
 in rec {
   inherit corePkgs coreLib;
 
   mkNetUdevRule = name: mac: ''
   ACTION=="add", SUBSYSTEM=="net", DRIVERS=="?*", KERNEL=="eth*", ATTR{address}=="${mac}", NAME="${name}"
@@ -33,23 +78,25 @@
 
   mkNetUdevRules = rs: concatStringsSep "\n" (mapAttrsToList (name: mac:
     mkNetUdevRule name mac
   ) rs);
 
-  inherit findConfig;
+  inherit findMetaConfig;
 
   # Return all configured machines in a list
   getClusterMachines = cluster:
-    mapAttrsToList (name: config:
-      makeMachine { inherit name config; }
-    ) cluster;
+    let
+      machineAttrs = mapAttrs (name: metaConfig:
+        makeMachine { inherit name metaConfig; }
+      ) cluster;
+    in expandCarriers machineAttrs;
 
   # Get IP version addresses from all machines in a cluster
   getAllAddressesOf = cluster: v:
     let
       machines = getClusterMachines cluster;
       addresses = flatten (map (machine:
-        map (addr: machine // addr) machine.config.addresses.${"v${toString v}"}
+        map (addr: machine // addr) machine.metaConfig.addresses.${"v${toString v}"}
       ) machines);
     in addresses;
 
   mkOptions = {
     addresses = v: