add postgres container

flake.nix

@@ -103,6 +103,16 @@
           ./hosts/hedgedoc
         ];
       };
+      nixosConfigurations."sql" = nixpkgs.lib.nixosSystem {
+        #system = "x86_64-linux";
+        #pkgs = import nixpkgs { inherit system; };
+        inherit system;
+        modules = [
+          agenix.nixosModules.default
+          { environment.systemPackages = [ (agenix.packages.${system}.default) ]; }
+          ./hosts/sql
+        ];
+      };
     };
   #);
 }