clan-config: add readme

Also add capability of reading an option value

README.md

@@ -1,6 +1,7 @@
 # clan.lol core
 
 This is the monorepo of the clan.lol project
-
 In here are all the packages we use, all the nixosModules we use/expose, the CLI and tests for everything.
-Not in here is the deployed infrastructure, which is in clan-infra.
+
+## cLAN config tool
+Find the docs [here](/docs/clan-config.md)

docs/clan-config.md

@@ -0,0 +1,65 @@
+# cLAN config
+
+`clan config` allows you to manage your nixos configuration via the terminal.
+Similar as how `git config` reads and sets git options, `clan config` does the same with your nixos options
+It also supports auto completion making it easy to find the right options.
+
+## Set up clan-config
+
+Add the clan tool to your flake inputs:
+
+```
+clan.url = "git+https://git.clan.lol/clan/clan-core";
+```
+
+and inside the mkFlake:
+```
+imports = [
+  inputs.clan.flakeModules.clan-config
+];
+```
+
+Add an empty config file and add it to git
+```command
+echo "{}" > ./clan-settings.json
+git add ./clan-settings.json
+```
+
+Import the clan-config module into your nixos configuration:
+```nix
+{
+  imports = [
+    # clan-settings.json is located in the same directory as your flake.
+    # Adapt the path if necessary.
+    (builtins.fromJSON (builtins.readFile ./clan-settings.json))
+  ];
+}
+
+
+```
+
+Make sure your nixos configuration is set a default
+```nix
+{self, ...}: {
+  flake.nixosConfigurations.default = self.nixosConfigurations.my-machine;
+}
+```
+
+Use all inputs provided by the clan-config devShell in your own devShell:
+
+```nix
+{ ... }: {
+  perSystem = { pkgs, self', ... }: {
+    devShells.default = pkgs.mkShell {
+      inputsFrom = [ self'.devShells.clan-config ];
+      # ...
+    };
+  };
+}
+```
+
+re-load your dev-shell to make the clan tool available.
+
+```command
+clan config --help
+```

flake.nix

@@ -27,11 +27,12 @@
         ./formatter.nix
         ./templates/flake-module.nix
 
+        ./flakeModules/clan-config.nix
+
         ./pkgs/flake-module.nix
 
         ./lib/flake-module.nix
         ({ self, lib, ... }: {
-          flake.flakeModules = lib.mapAttrs (_: nix: { imports = [ nix ]; }) (self.lib.findNixFiles ./flakeModules);
           flake.clanModules = lib.mapAttrs (_: nix: { imports = [ nix ]; }) (self.lib.findNixFiles ./clanModules);
           flake.nixosModules = lib.mapAttrs (_: nix: { imports = [ nix ]; }) (self.lib.findNixFiles ./nixosModules);
         })

flakeModules/clan-config.nix

@@ -1,40 +1,42 @@
-{ self, inputs, ... }:
-let
+{ ... } @ clanCore: {
+  flake.flakeModules.clan-config = { self, inputs, ... }:
+    let
 
-  # take the default nixos configuration
-  options = self.nixosConfigurations.default.options;
+      # take the default nixos configuration
+      options = self.nixosConfigurations.default.options;
 
-  # this is actually system independent as it uses toFile
-  docs = inputs.nixpkgs.legacyPackages.x86_64-linux.nixosOptionsDoc {
-    inherit options;
-  };
+      # this is actually system independent as it uses toFile
+      docs = inputs.nixpkgs.legacyPackages.x86_64-linux.nixosOptionsDoc {
+        inherit options;
+      };
 
-  optionsJSONFile = docs.optionsJSON.options;
+      optionsJSONFile = docs.optionsJSON.options;
 
-  warnIfNoDefaultConfig = return:
-    if ! self ? nixosConfigurations.default
-    then
-      builtins.trace
-        "WARNING: .#nixosConfigurations.default could not be found. Please define it."
-        return
-    else return;
+      warnIfNoDefaultConfig = return:
+        if ! self ? nixosConfigurations.default
+        then
+          builtins.trace
+            "WARNING: .#nixosConfigurations.default could not be found. Please define it."
+            return
+        else return;
 
-in
-{
-  flake.clanOptions = warnIfNoDefaultConfig optionsJSONFile;
+    in
+    {
+      flake.clanOptions = warnIfNoDefaultConfig optionsJSONFile;
 
-  flake.clanSettings = self + /clan-settings.json;
+      flake.clanSettings = self + /clan-settings.json;
 
-  perSystem = { pkgs, inputs', ... }: {
-    devShells.clan-config = pkgs.mkShell {
-      packages = [
-        inputs'.clan-core.packages.clan-cli
-      ];
-      shellHook = ''
-        export CLAN_OPTIONS_FILE=$(nix eval --raw .#clanOptions)
-        export XDG_DATA_DIRS="${inputs'.clan-core.packages.clan-cli}/share''${XDG_DATA_DIRS:+:$XDG_DATA_DIRS}"
-        export fish_complete_path="${inputs'.clan-core.packages.clan-cli}/share/fish/vendor_completions.d''${fish_complete_path:+:$fish_complete_path}"
-      '';
+      perSystem = { pkgs, ... }: {
+        devShells.clan-config = pkgs.mkShell {
+          packages = [
+            clanCore.config.flake.packages.${pkgs.system}.clan-cli
+          ];
+          shellHook = ''
+            export CLAN_OPTIONS_FILE=$(nix eval --raw .#clanOptions)
+            export XDG_DATA_DIRS="${clanCore.config.flake.packages.${pkgs.system}.clan-cli}/share''${XDG_DATA_DIRS:+:$XDG_DATA_DIRS}"
+            export fish_complete_path="${clanCore.config.flake.packages.${pkgs.system}.clan-cli}/share/fish/vendor_completions.d''${fish_complete_path:+:$fish_complete_path}"
+          '';
+        };
+      };
     };
-  };
 }

pkgs/clan-cli/clan_cli/config/__init__.py

@@ -43,7 +43,7 @@ def merge(a: dict, b: dict, path: list[str] = []) -> dict:
             elif isinstance(a[key], list) and isinstance(b[key], list):
                 a[key].extend(b[key])
             elif a[key] != b[key]:
-                raise Exception("Conflict at " + ".".join(path + [str(key)]))
+                a[key] = b[key]
         else:
             a[key] = b[key]
     return a
@@ -91,13 +91,49 @@ def cast(value: Any, type: Type, opt_description: str) -> Any:
         )
 
 
+def read_option(option: str) -> str:
+    # use nix eval to read from .#nixosConfigurations.default.config.{option}
+    # this will give us the evaluated config with the options attribute
+    proc = subprocess.run(
+        [
+            "nix",
+            "eval",
+            "--json",
+            f".#nixosConfigurations.default.config.{option}",
+        ],
+        capture_output=True,
+        text=True,
+    )
+    if proc.returncode != 0:
+        print(proc.stderr, file=sys.stderr)
+        raise ClanError(f"Failed to read option {option}:\n{proc.stderr}")
+    value = json.loads(proc.stdout)
+    # print the value so that the output can be copied and fed as an input.
+    # for example a list should be displayed as space separated values surrounded by quotes.
+    if isinstance(value, list):
+        out = " ".join([json.dumps(x) for x in value])
+    elif isinstance(value, dict):
+        out = json.dumps(value, indent=2)
+    else:
+        out = json.dumps(value, indent=2)
+    return out
+
+
 def process_args(
-    option: str, value: Any, options: dict, out_file: Path, option_description: str = ""
+    option: str,
+    value: Any,
+    options: dict,
+    settings_file: Path,
+    option_description: str = "",
 ) -> None:
+    if value == []:
+        print(read_option(option))
+        return
+
     option_path = option.split(".")
 
     # if the option cannot be found, then likely the type is attrs and we need to
-    # find the parent option
+    # find the parent option.
     if option not in options:
         if len(option_path) == 1:
             raise ClanError(f"Option {option_description} not found")
@@ -107,11 +143,12 @@ def process_args(
             option=".".join(option_parent),
             value={attr: value},
             options=options,
-            out_file=out_file,
+            settings_file=settings_file,
             option_description=option,
         )
 
     target_type = map_type(options[option]["type"])
+    casted = cast(value, target_type, option)
 
     # construct a nested dict from the option path and set the value
     result: dict[str, Any] = {}
@@ -121,22 +158,21 @@ def process_args(
         current = current[part]
     current[option_path[-1]] = value
 
-    casted = cast(value, target_type, option)
-
     current[option_path[-1]] = casted
 
     # check if there is an existing config file
-    if os.path.exists(out_file):
-        with open(out_file) as f:
+    if os.path.exists(settings_file):
+        with open(settings_file) as f:
             current_config = json.load(f)
     else:
         current_config = {}
     # merge and save the new config file
     new_config = merge(current_config, result)
-    with open(out_file, "w") as f:
+    with open(settings_file, "w") as f:
         json.dump(new_config, f, indent=2)
-    print("New config:")
-    print(json.dumps(new_config, indent=2))
+    new_value = read_option(option)
+    print(f"New Value for {option}:")
+    print(new_value)
 
 
 def register_parser(
@@ -182,13 +218,13 @@ def _register_parser(
             option=args.option,
             value=args.value,
             options=options,
-            out_file=args.out_file,
+            settings_file=args.settings_file,
         )
     )
 
     # add argument to pass output file
     parser.add_argument(
-        "--out-file",
+        "--settings-file",
         "-o",
         help="Output file",
         type=Path,
@@ -198,8 +234,6 @@ def _register_parser(
     # add single positional argument for the option (e.g. "foo.bar")
     parser.add_argument(
         "option",
-        # force this arg to be set
-        nargs="?",
         help="Option to configure",
         type=str,
         choices=AllContainer(list(options.keys())),
@@ -209,7 +243,7 @@ def _register_parser(
     parser.add_argument(
         "value",
         # force this arg to be set
-        nargs="+",
+        nargs="*",
         help="Value to set",
     )
 

pkgs/clan-cli/tests/test_config.py

@@ -37,7 +37,7 @@ def test_set_some_option(
     with tempfile.NamedTemporaryFile() as out_file:
         with open(out_file.name, "w") as f:
             json.dump({}, f)
-        monkeypatch.setattr(sys, "argv", ["", "--out-file", out_file.name] + argv)
+        monkeypatch.setattr(sys, "argv", ["", "--settings-file", out_file.name] + argv)
         parser = argparse.ArgumentParser()
         config._register_parser(
             parser=parser,