Make --network accept a file argument and add a --flake flag

To make it possible to keep multiple network definitions in the same
directory, make the `--network` flag accept a file in addition to a
directory. Also, add a corresponding `--flake` flag and create short
flags for both (`-n` and `-f` respectively).

Author: talyz

nixops/args.py

@@ -61,20 +61,19 @@
 subparser = add_subparser(subparsers, "create", help="create a new deployment")
 subparser.set_defaults(op=op_create)
 subparser.add_argument(
-    "--name", "-n", dest="name", metavar="NAME", help=SUPPRESS
+    "--name", dest="name", metavar="NAME", help=SUPPRESS
 )  # obsolete, use -d instead
 
 subparser = add_subparser(subparsers, "modify", help="modify an existing deployment")
 subparser.set_defaults(op=op_modify)
 subparser.add_argument(
-    "--name", "-n", dest="name", metavar="NAME", help="new symbolic name of deployment"
+    "--name", dest="name", metavar="NAME", help="new symbolic name of deployment"
 )
 
 subparser = add_subparser(subparsers, "clone", help="clone an existing deployment")
 subparser.set_defaults(op=op_clone)
 subparser.add_argument(
     "--name",
-    "-n",
     dest="name",
     metavar="NAME",
     help="symbolic name of the cloned deployment",

nixops/script_defs.py

@@ -37,27 +37,38 @@
 
 
 def get_network_file(args: Namespace) -> NetworkFile:
-    network_dir: str = os.path.abspath(args.network_dir)
-
-    if not os.path.exists(network_dir):
-        raise ValueError("f{network_dir} does not exist")
-
-    classic_path = os.path.join(network_dir, "nixops.nix")
-    flake_path = os.path.join(network_dir, "flake.nix")
-
-    classic_exists: bool = os.path.exists(classic_path)
+    if args.network_path is not None:
+        network_path: str = os.path.abspath(args.network_path)
+        if os.path.isdir(network_path):
+            network_path = os.path.join(network_path, "nixops.nix")
+        if not os.path.exists(network_path):
+            raise ValueError(f"{network_path} does not exist")
+        return NetworkFile(network=network_path, is_flake=False)
+
+    if args.flake_path is not None:
+        flake_path: str = os.path.abspath(args.flake_path)
+        if os.path.isdir(flake_path):
+            flake_path = os.path.join(flake_path, "flake.nix")
+        if not os.path.exists(flake_path):
+            raise ValueError(f"{flake_path} does not exist")
+        return NetworkFile(network=flake_path, is_flake=True)
+
+    network_path: str = os.path.join(os.getcwd(), "nixops.nix")
+    flake_path: str = os.path.join(os.getcwd(), "flake.nix")
+
+    network_exists: bool = os.path.exists(network_path)
     flake_exists: bool = os.path.exists(flake_path)
 
-    if all((flake_exists, classic_exists)):
-        raise ValueError("Both flake.nix and nixops.nix cannot coexist")
-
-    if classic_exists:
-        return NetworkFile(network=classic_path, is_flake=False)
+    if all((flake_exists, network_exists)):
+        raise ValueError("Both flake.nix and nixops.nix found in current directory")
 
-    if flake_exists:
-        return NetworkFile(network=network_dir, is_flake=True)
+    if not network_exists and not flake_exists:
+        raise ValueError("Neither flake.nix nor nixops.nix exists in current directory")
 
-    raise ValueError(f"Neither flake.nix nor nixops.nix exists in {network_dir}")
+    if network_exists:
+        return NetworkFile(network=network_path, is_flake=False)
+    else:
+        return NetworkFile(network=network_path, is_flake=True)
 
 
 def set_common_depl(depl: nixops.deployment.Deployment, args: Namespace) -> None:
@@ -1127,12 +1138,20 @@ def add_subparser(
     subparsers: _SubParsersAction, name: str, help: str
 ) -> ArgumentParser:
     subparser = subparsers.add_parser(name, help=help)
-    subparser.add_argument(
+    network = subparser.add_mutually_exclusive_group()
+    network.add_argument(
         "--network",
-        dest="network_dir",
+        "-n",
+        dest="network_path",
+        metavar="FILE",
+        help="path to network file or a directory containing nixops.nix",
+    )
+    network.add_argument(
+        "--flake",
+        "-f",
+        dest="flake_path",
         metavar="FILE",
-        default=os.getcwd(),
-        help="path to a directory containing either nixops.nix or flake.nix",
+        help="path to flake or a directory containing flake.nix",
     )
     subparser.add_argument(
         "--deployment",