webui: implement /api/machines/{name}/schema

pkgs/clan-cli/tests/config/example_flake/clanModules/machine1.nix

@@ -0,0 +1,7 @@
+{ lib, ... }: {
+  options.clan.jitsi.enable = lib.mkOption {
+    type = lib.types.bool;
+    default = false;
+    description = "Enable jitsi on this machine";
+  };
+}

pkgs/clan-cli/tests/config/example_flake/flake.nix

@@ -0,0 +1,10 @@
+{
+  inputs = {
+    # this placeholder is replaced by the path to nixpkgs
+    nixpkgs.url = "__CLAN_NIXPKGS__";
+  };
+
+  outputs = _inputs: {
+    clanModules.machine-machine1 = ./clanModules/machine1.nix;
+  };
+}

pkgs/clan-cli/tests/config/test_machine_schema.py

@@ -0,0 +1,44 @@
+import os
+import tempfile
+from pathlib import Path
+from typing import Generator
+
+import pytest
+
+from clan_cli.config import machine
+
+CLAN_NIXPKGS = os.environ.get("CLAN_NIXPKGS", "")
+if CLAN_NIXPKGS == "":
+    raise Exception("CLAN_NIXPKGS not set")
+
+
+# fixture for the example flake located under ./example_flake
+# The flake is a template that is copied to a temporary location.
+# Variables like __CLAN_NIXPKGS__ are replaced with the value of the
+# CLAN_NIXPKGS environment variable.
+@pytest.fixture
+def flake_dir() -> Generator[Path, None, None]:
+    template = Path(__file__).parent / "example_flake"
+    # copy the template to a new temporary location
+    with tempfile.TemporaryDirectory() as tmpdir_:
+        tmpdir = Path(tmpdir_)
+        for path in template.glob("**/*"):
+            if path.is_dir():
+                (tmpdir / path.relative_to(template)).mkdir()
+            else:
+                (tmpdir / path.relative_to(template)).write_text(path.read_text())
+        # in the flake.nix file replace the string __CLAN_URL__ with the the clan flake
+        # provided by get_clan_flake_toplevel
+        flake_nix = tmpdir / "flake.nix"
+        flake_nix.write_text(
+            flake_nix.read_text().replace("__CLAN_NIXPKGS__", CLAN_NIXPKGS)
+        )
+        yield tmpdir
+
+
+def test_schema_for_machine(
+    flake_dir: Path, tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    monkeypatch.chdir(tmp_path)
+    schema = machine.schema_for_machine("machine1", flake_dir)
+    assert "properties" in schema