Merge pull request 'clan_cli: add select command' (#2815) from kenji/clan-core:lass/clan-select into main

Reviewed-on: https://git.clan.lol/clan/clan-core/pulls/2815

docs/mkdocs.yml

@@ -121,6 +121,7 @@ nav:
           - reference/cli/flash.md
           - reference/cli/history.md
           - reference/cli/machines.md
+          - reference/cli/select.md
           - reference/cli/secrets.md
           - reference/cli/show.md
           - reference/cli/ssh.md

pkgs/clan-cli/clan_cli/__init__.py

@@ -18,6 +18,7 @@ from . import (
     clan,
     history,
     secrets,
+    select,
     state,
     vms,
 )
@@ -373,6 +374,30 @@ For more detailed information, visit: {help_hyperlink("deploy", "https://docs.cl
     )
     history.register_parser(parser_history)
 
+    parser_select = subparsers.add_parser(
+        "select",
+        help="Select nixos values from the flake",
+        description="Select nixos values from the flake",
+        epilog=(
+            """
+This subcommand provides an interface nix values defined in the flake.
+
+Examples:
+
+  $ clan select nixosConfigurations.*.config.networking.hostName
+    List hostnames of all nixos configurations as JSON.
+
+  $ clan select nixosConfigurations.{jon,alice}.config.clan.core.vars.generators.*.name
+    List all vars generators for jon and alice.
+
+  $ clan select nixosConfigurations.jon.config.envirnonment.systemPackages.1
+    List the first system package for jon.
+        """
+        ),
+        formatter_class=argparse.RawTextHelpFormatter,
+    )
+    select.register_parser(parser_select)
+
     parser_state = subparsers.add_parser(
         "state",
         help="Query state information about machines",

pkgs/clan-cli/clan_cli/flake.py

@@ -192,7 +192,6 @@ class FlakeCacheEntry:
                     self.value[sel].is_cached(selectors[1:]) for sel in self.value
                 )
             # TODO: check if we already have all the keys anyway?
-            print("not cached because self.selector is not all")
             return False
         if (
             isinstance(selector, set)
@@ -200,15 +199,12 @@ class FlakeCacheEntry:
             and isinstance(self.value, dict)
         ):
             if not selector.issubset(self.selector):
-                print("not cached because selector is not subset of self.selector")
                 return False
             return all(self.value[sel].is_cached(selectors[1:]) for sel in selector)
         if isinstance(selector, str | int) and isinstance(self.value, dict):
             if selector in self.value:
                 return self.value[selector].is_cached(selectors[1:])
-            print("not cached because selector is not in self.value")
             return False
-        print("not cached because of unknown reason")
         return False
 
     def select(self, selectors: list[Selector]) -> Any:
@@ -307,6 +303,5 @@ class Flake:
     def select(self, selector: str) -> Any:
         if not self.cache.is_cached(selector):
             log.info(f"Cache miss for {selector}")
-            print(f"Cache miss for {selector}")
             self.prepare_cache([selector])
         return self.cache.select(selector)

pkgs/clan-cli/clan_cli/select.py

@@ -0,0 +1,17 @@
+import argparse
+import json
+
+from clan_cli.flake import Flake
+
+
+def select_command(args: argparse.Namespace) -> None:
+    flake = Flake(args.flake.path)
+    print(json.dumps(flake.select(args.selector), indent=4))
+
+
+def register_parser(parser: argparse.ArgumentParser) -> None:
+    parser.set_defaults(func=select_command)
+    parser.add_argument(
+        "selector",
+        help="select from a flake",
+    )