vars: implement prompts

nixosModules/clanCore/vars/default.nix

@@ -39,7 +39,7 @@ in
     vars = {
       generators = lib.flip lib.mapAttrs config.clan.core.vars.generators (
         _name: generator: {
-          inherit (generator) dependencies finalScript;
+          inherit (generator) dependencies finalScript prompts;
           files = lib.flip lib.mapAttrs generator.files (_name: file: { inherit (file) secret; });
         }
       );

nixosModules/clanCore/vars/interface.nix

@@ -108,8 +108,9 @@ in
                 Prompts are available to the generator script as files.
                 For example, a prompt named 'prompt1' will be available via $prompts/prompt1
               '';
+              default = { };
               type = attrsOf (submodule {
-                options = {
+                options = options {
                   description = {
                     description = ''
                       The description of the prompted value

pkgs/clan-cli/clan_cli/vars/generate.py

@@ -2,9 +2,8 @@ import argparse
 import importlib
 import logging
 import os
-import subprocess
 import sys
-from collections.abc import Callable
+from getpass import getpass
 from graphlib import TopologicalSorter
 from pathlib import Path
 from tempfile import TemporaryDirectory
@@ -29,17 +28,7 @@ from .secret_modules import SecretStoreBase
 log = logging.getLogger(__name__)
 
 
-def read_multiline_input(prompt: str = "Finish with Ctrl-D") -> str:
-    """
-    Read multi-line input from stdin.
-    """
-    print(prompt, flush=True)
-    proc = subprocess.run(["cat"], stdout=subprocess.PIPE, text=True)
-    log.info("Input received. Processing...")
-    return proc.stdout
-
-
-def bubblewrap_cmd(generator: str, generator_dir: Path, dep_tmpdir: Path) -> list[str]:
+def bubblewrap_cmd(generator: str, tmpdir: Path) -> list[str]:
     # fmt: off
     return nix_shell(
         [
@@ -51,8 +40,7 @@ def bubblewrap_cmd(generator: str, generator_dir: Path, dep_tmpdir: Path) -> lis
             "--ro-bind", "/nix/store", "/nix/store",
             "--tmpfs",  "/usr/lib/systemd",
             "--dev", "/dev",
-            "--bind", str(generator_dir), str(generator_dir),
-            "--ro-bind", str(dep_tmpdir), str(dep_tmpdir),
+            "--bind", str(tmpdir), str(tmpdir),
             "--unshare-all",
             "--unshare-user",
             "--uid", "1000",
@@ -92,7 +80,7 @@ def decrypt_dependencies(
 def dependencies_as_dir(
     decrypted_dependencies: dict[str, dict[str, bytes]],
     tmpdir: Path,
-) -> Path:
+) -> None:
     for dep_generator, files in decrypted_dependencies.items():
         dep_generator_dir = tmpdir / dep_generator
         dep_generator_dir.mkdir()
@@ -102,7 +90,6 @@ def dependencies_as_dir(
             file_path.touch()
             file_path.chmod(0o600)
             file_path.write_bytes(file)
-    return tmpdir
 
 
 def execute_generator(
@@ -111,10 +98,7 @@ def execute_generator(
     regenerate: bool,
     secret_vars_store: SecretStoreBase,
     public_vars_store: FactStoreBase,
-    dep_tmpdir: Path,
-    prompt: Callable[[str], str],
 ) -> bool:
-    generator_dir = dep_tmpdir / generator_name
     # check if all secrets exist and generate them if at least one is missing
     needs_regeneration = not check_secrets(machine, generator_name=generator_name)
     log.debug(f"{generator_name} needs_regeneration: {needs_regeneration}")
@@ -124,51 +108,65 @@ def execute_generator(
         msg = f"flake is not a Path: {machine.flake}"
         msg += "fact/secret generation is only supported for local flakes"
 
-    # compatibility for old outputs.nix users
     generator = machine.vars_generators[generator_name]["finalScript"]
-    # if machine.vars_data[generator_name]["generator"]["prompt"]:
-    #     prompt_value = prompt(machine.vars_data[generator_name]["generator"]["prompt"])
-    #     env["prompt_value"] = prompt_value
 
     # build temporary file tree of dependencies
     decrypted_dependencies = decrypt_dependencies(
         machine, generator_name, secret_vars_store, public_vars_store
     )
     env = os.environ.copy()
-    generator_dir.mkdir(parents=True)
-    env["out"] = str(generator_dir)
     with TemporaryDirectory() as tmp:
-        dep_tmpdir = dependencies_as_dir(decrypted_dependencies, Path(tmp))
-        env["in"] = str(dep_tmpdir)
+        tmpdir = Path(tmp)
+        tmpdir_in = tmpdir / "in"
+        tmpdir_prompts = tmpdir / "prompts"
+        tmpdir_out = tmpdir / "out"
+        tmpdir_in.mkdir()
+        tmpdir_out.mkdir()
+        env["in"] = str(tmpdir_in)
+        env["out"] = str(tmpdir_out)
+        # populate dependency inputs
+        dependencies_as_dir(decrypted_dependencies, tmpdir_in)
+        # populate prompted values
+        # TODO: make prompts rest API friendly
+        if machine.vars_generators[generator_name]["prompts"]:
+            tmpdir_prompts.mkdir()
+            env["prompts"] = str(tmpdir_prompts)
+            for prompt_name, prompt in machine.vars_generators[generator_name][
+                "prompts"
+            ].items():
+                prompt_file = tmpdir_prompts / prompt_name
+                value = prompt_func(prompt["description"], prompt["type"])
+                prompt_file.write_text(value)
+
         if sys.platform == "linux":
-            cmd = bubblewrap_cmd(generator, generator_dir, dep_tmpdir=dep_tmpdir)
+            cmd = bubblewrap_cmd(generator, tmpdir)
         else:
             cmd = ["bash", "-c", generator]
         run(
             cmd,
             env=env,
         )
-    files_to_commit = []
-    # store secrets
-    files = machine.vars_generators[generator_name]["files"]
-    for file_name, file in files.items():
-        groups = machine.deployment["sops"]["defaultGroups"]
+        files_to_commit = []
+        # store secrets
+        files = machine.vars_generators[generator_name]["files"]
+        for file_name, file in files.items():
+            groups = machine.deployment["sops"]["defaultGroups"]
 
-        secret_file = generator_dir / file_name
-        if not secret_file.is_file():
-            msg = f"did not generate a file for '{file_name}' when running the following command:\n"
-            msg += generator
-            raise ClanError(msg)
-        if file["secret"]:
-            file_path = secret_vars_store.set(
-                generator_name, file_name, secret_file.read_bytes(), groups
-            )
-        else:
-            file_path = public_vars_store.set(
-                generator_name, file_name, secret_file.read_bytes()
-            )
-        if file_path:
-            files_to_commit.append(file_path)
+            secret_file = tmpdir_out / file_name
+            if not secret_file.is_file():
+                msg = f"did not generate a file for '{file_name}' when running the following command:\n"
+                msg += generator
+                raise ClanError(msg)
+            if file["secret"]:
+                file_path = secret_vars_store.set(
+                    generator_name, file_name, secret_file.read_bytes(), groups
+                )
+            else:
+                file_path = public_vars_store.set(
+                    generator_name, file_name, secret_file.read_bytes()
+                )
+            if file_path:
+                files_to_commit.append(file_path)
     commit_files(
         files_to_commit,
         machine.flake_dir,
@@ -177,9 +175,18 @@ def execute_generator(
     return True
 
 
-def prompt_func(text: str) -> str:
-    print(f"{text}: ")
-    return read_multiline_input()
+def prompt_func(description: str, input_type: str) -> str:
+    if input_type == "line":
+        result = input(f"Enter the value for {description}: ")
+    elif input_type == "multiline":
+        print(f"Enter the value for {description} (Finish with Ctrl-D): ")
+        result = sys.stdin.read()
+    elif input_type == "hidden":
+        result = getpass(f"Enter the value for {description} (hidden): ")
+    else:
+        raise ClanError(f"Unknown input type: {input_type} for prompt {description}")
+    log.info("Input received. Processing...")
+    return result
 
 
 def _get_subgraph(graph: dict[str, set], vertex: str) -> dict[str, set]:
@@ -197,11 +204,7 @@ def _generate_vars_for_machine(
     machine: Machine,
     generator_name: str | None,
     regenerate: bool,
-    tmpdir: Path,
-    prompt: Callable[[str], str] = prompt_func,
 ) -> bool:
-    local_temp = tmpdir / machine.name
-    local_temp.mkdir()
     secret_vars_module = importlib.import_module(machine.secret_vars_module)
     secret_vars_store = secret_vars_module.SecretStore(machine=machine)
 
@@ -216,13 +219,6 @@ def _generate_vars_for_machine(
             f"Could not find generator with name: {generator_name}. The following generators are available: {generators}"
         )
 
-    # if generator_name:
-    #     machine_generator_facts = {
-    #         generator_name: machine.vars_generators[generator_name]
-    #     }
-    # else:
-    #     machine_generator_facts = machine.vars_generators
-
     graph = {
         gen_name: set(generator["dependencies"])
         for gen_name, generator in machine.vars_generators.items()
@@ -250,8 +246,6 @@ def _generate_vars_for_machine(
             regenerate=regenerate,
             secret_vars_store=secret_vars_store,
             public_vars_store=public_vars_store,
-            dep_tmpdir=local_temp,
-            prompt=prompt,
         )
     if machine_updated:
         # flush caches to make sure the new secrets are available in evaluation
@@ -263,25 +257,21 @@ def generate_vars(
     machines: list[Machine],
     generator_name: str | None,
     regenerate: bool,
-    prompt: Callable[[str], str] = prompt_func,
 ) -> bool:
     was_regenerated = False
-    with TemporaryDirectory() as tmp:
-        tmpdir = Path(tmp)
-
-        for machine in machines:
-            errors = 0
-            try:
-                was_regenerated |= _generate_vars_for_machine(
-                    machine, generator_name, regenerate, tmpdir, prompt
-                )
-            except Exception as exc:
-                log.error(f"Failed to generate facts for {machine.name}: {exc}")
-                errors += 1
-            if errors > 0:
-                raise ClanError(
-                    f"Failed to generate facts for {errors} hosts. Check the logs above"
-                )
+    for machine in machines:
+        errors = 0
+        try:
+            was_regenerated |= _generate_vars_for_machine(
+                machine, generator_name, regenerate
+            )
+        except Exception as exc:
+            log.error(f"Failed to generate facts for {machine.name}: {exc}")
+            errors += 1
+        if errors > 0:
+            raise ClanError(
+                f"Failed to generate facts for {errors} hosts. Check the logs above"
+            )
 
     if not was_regenerated:
         print("All secrets and facts are already up to date")

pkgs/clan-cli/tests/test_vars.py

@@ -1,6 +1,7 @@
 import os
 from collections import defaultdict
 from collections.abc import Callable
+from io import StringIO
 from pathlib import Path
 from tempfile import TemporaryDirectory
 from typing import Any
@@ -55,7 +56,8 @@ def test_dependencies_as_files() -> None:
         ),
     )
     with TemporaryDirectory() as tmpdir:
-        dep_tmpdir = dependencies_as_dir(decrypted_dependencies, Path(tmpdir))
+        dep_tmpdir = Path(tmpdir)
+        dependencies_as_dir(decrypted_dependencies, dep_tmpdir)
         assert dep_tmpdir.is_dir()
         assert (dep_tmpdir / "gen_1" / "var_1a").read_bytes() == b"var_1a"
         assert (dep_tmpdir / "gen_1" / "var_1b").read_bytes() == b"var_1b"
@@ -232,3 +234,40 @@ def test_dependant_generators(
     )
     assert child_file_path.is_file()
     assert child_file_path.read_text() == "hello\n"
+
+
+@pytest.mark.impure
+@pytest.mark.parametrize(
+    ("prompt_type", "input_value"),
+    [
+        ("line", "my input"),
+        ("multiline", "my\nmultiline\ninput\n"),
+        # The hidden type cannot easily be tested, as getpass() reads from /dev/tty directly
+        # ("hidden", "my hidden input"),
+    ],
+)
+def test_prompt(
+    monkeypatch: pytest.MonkeyPatch,
+    temporary_home: Path,
+    prompt_type: str,
+    input_value: str,
+) -> None:
+    config = nested_dict()
+    my_generator = config["clan"]["core"]["vars"]["generators"]["my_generator"]
+    my_generator["files"]["my_value"]["secret"] = False
+    my_generator["prompts"]["prompt1"]["description"] = "dream2nix"
+    my_generator["prompts"]["prompt1"]["type"] = prompt_type
+    my_generator["script"] = "cat $prompts/prompt1 > $out/my_value"
+    flake = generate_flake(
+        temporary_home,
+        flake_template=CLAN_CORE / "templates" / "minimal",
+        machine_configs=dict(my_machine=config),
+    )
+    monkeypatch.chdir(flake.path)
+    monkeypatch.setattr("sys.stdin", StringIO(input_value))
+    cli.run(["vars", "generate", "--flake", str(flake.path), "my_machine"])
+    var_file_path = (
+        flake.path / "machines" / "my_machine" / "vars" / "my_generator" / "my_value"
+    )
+    assert var_file_path.is_file()
+    assert var_file_path.read_text() == input_value