feat(infra): Internalize nix-lib, and make keys management simpler

meta/options.nix

@@ -368,10 +368,10 @@ in
           name: "A member of the external service ${name} admins was not found in the members list."
         ) org.external)
 
-        # Check that all members have a keyFile
+        # Check that all members have ssh keys
         (builtins.map (name: {
-          assertion = builtins.pathExists "${builtins.toString ../keys}/${name}.keys";
-          message = "No ssh keys file found for ${name}.";
+          assertion = ((import ../keys)._keys.${name} or [ ]) != [ ];
+          message = "No ssh keys found for ${name}.";
         }) members)
       ];
     };

meta/verify.nix

@@ -5,12 +5,6 @@ let
   pkgs = import sources.nixpkgs { };
 
   dns = import sources."dns.nix" { inherit pkgs; };
-
-  lib = import sources.nix-lib {
-    inherit (pkgs) lib;
-
-    keysRoot = ../keys;
-  };
 in
 
 {
@@ -29,6 +23,14 @@ in
       pkgs.writers.writeJSON "meta.json" config;
 
   dns = dns.util.writeZone "dgnum.eu" (
-    pkgs.lib.recursiveUpdate { SOA.serial = 0; } (import ./dns.nix { inherit dns lib; })
+    pkgs.lib.recursiveUpdate { SOA.serial = 0; } (
+      import ./dns.nix {
+        inherit dns;
+
+        lib = pkgs.lib // {
+          extra = import ../lib/nix-lib;
+        };
+      }
+    )
   );
 }