cluster/lib: implement meshLinks

cluster/default.nix

@@ -14,6 +14,7 @@ lib.evalModules {
     ./lib/services.nix
     ./lib/inject-nixos-config.nix
     ./lib/port-magic-multi.nix
+    ./lib/mesh.nix
 
     ./import-services.nix
   ];

cluster/lib/mesh.nix

@@ -0,0 +1,15 @@
+{ config, lib, ... }:
+
+{
+  hostLinks = lib.pipe config.services [
+    (lib.filterAttrs (_: svc: svc.meshLinks != {}))
+    (lib.mapAttrsToList (svcName: svc: lib.mapAttrsToList (name: cfg: lib.genAttrs svc.nodes.${name} (hostName: {
+      ${cfg.name} = { ... }: {
+        imports = [ cfg.link ];
+        ipv4 = config.vars.mesh.${hostName}.meshIp;
+      };
+    })) svc.meshLinks))
+    (map lib.mkMerge)
+    lib.mkMerge
+  ];
+}

cluster/lib/service-module.nix

@@ -1,8 +1,9 @@
-{ config, lib, ... }:
+{ config, lib, name, ... }:
 with lib;
 
 let
   filterGroup = group: hostName: builtins.filter (x: x != hostName) group;
+  serviceName = name;
 in
 
 {
@@ -31,6 +32,22 @@ in
       type = with types; attrs;
       default = {};
     };
+    meshLinks = mkOption {
+      description = "Create host links on the mesh network.";
+      type = types.attrsOf (types.submodule ({ name, ... }: {
+        options = {
+          name = mkOption {
+            type = types.str;
+            default = "${serviceName}-${name}";
+          };
+          link = mkOption {
+            type = types.deferredModule;
+            default = {};
+          };
+        };
+      }));
+      default = {};
+    };
   };
   config.otherNodes = builtins.mapAttrs (const filterGroup) config.nodes;
 }