hermes-agent/tests/hermes_cli/test_container_aware_cli.py
Siddharth Balyan cab814af15
feat(nix): container-aware CLI — auto-route into managed container (#7543)
* feat(nix): container-aware CLI — auto-route all subcommands into managed container

When container.enable = true, the host `hermes` CLI transparently execs
every subcommand into the managed Docker/Podman container. A symlink
bridge (~/.hermes -> /var/lib/hermes/.hermes) unifies state between host
and container so sessions, config, and memories are shared.

CLI changes:
- Global routing before subcommand dispatch (all commands forwarded)
- docker exec with -u exec_user, env passthrough (TERM, COLORTERM,
  LANG, LC_ALL), TTY-aware flags
- Retry with spinner on failure (TTY: 5s, non-TTY: 10s silent)
- Hard fail instead of silent fallback
- HERMES_DEV=1 env var bypasses routing for development
- No routing messages (invisible to user)

NixOS module changes:
- container.hostUsers option: lists users who get ~/.hermes symlink
  and automatic hermes group membership
- Activation script creates symlink bridge (with backup of existing
  ~/.hermes dirs), writes exec_user to .container-mode
- Cleanup on disable: removes symlinks + .container-mode + stops service
- Warning when hostUsers set without addToSystemPackages

* fix: address review — reuse sudo var, add chown -h on symlink update

- hermes_cli/main.py: reuse the existing `sudo` variable instead of
  redundant `shutil.which("sudo")` call that could return None
- nix/nixosModules.nix: add missing `chown -h` when updating an
  existing symlink target so ownership stays consistent with the
  fresh-create and backup-replace branches

* fix: address remaining review items from cursor bugbot

- hermes_cli/main.py: move container routing BEFORE parse_args() so
  --help, unrecognised flags, and all subcommands are forwarded
  transparently into the container instead of being intercepted by
  argparse on the host (high severity)

- nix/nixosModules.nix: resolve home dirs via
  config.users.users.${user}.home instead of hardcoding /home/${user},
  supporting users with custom home directories (medium severity)

- nix/nixosModules.nix: gate hostUsers group membership on
  container.enable so setting hostUsers without container mode doesn't
  silently add users to the hermes group (low severity)

* fix: simplify container routing — execvp, no retries, let it crash

- Replace subprocess.run retry loop with os.execvp (no idle parent process)
- Extract _probe_container helper for sudo detection with 15s timeout
- Narrow exception handling: FileNotFoundError only in get_container_exec_info,
  catch TimeoutExpired specifically, remove silent except Exception: pass
- Collapse needs_sudo + sudo into single sudo_path variable
- Simplify NixOS symlink creation from 4 branches to 2
- Gate NixOS sudoers hint with "On NixOS:" prefix
- Full test rewrite: 18 tests covering execvp, sudo probe, timeout, permissions

---------

Co-authored-by: Hermes Agent <hermes@nousresearch.com>
2026-04-12 05:17:46 +05:30

342 lines
12 KiB
Python

"""Tests for container-aware CLI routing (NixOS container mode).
When container.enable = true in the NixOS module, the activation script
writes a .container-mode metadata file. The host CLI detects this and
execs into the container instead of running locally.
"""
import os
import subprocess
from pathlib import Path
from unittest.mock import MagicMock, patch
import pytest
from hermes_cli.config import (
_is_inside_container,
get_container_exec_info,
)
# =============================================================================
# _is_inside_container
# =============================================================================
def test_is_inside_container_dockerenv():
"""Detects /.dockerenv marker file."""
with patch("os.path.exists") as mock_exists:
mock_exists.side_effect = lambda p: p == "/.dockerenv"
assert _is_inside_container() is True
def test_is_inside_container_containerenv():
"""Detects Podman's /run/.containerenv marker."""
with patch("os.path.exists") as mock_exists:
mock_exists.side_effect = lambda p: p == "/run/.containerenv"
assert _is_inside_container() is True
def test_is_inside_container_cgroup_docker():
"""Detects 'docker' in /proc/1/cgroup."""
with patch("os.path.exists", return_value=False), \
patch("builtins.open", create=True) as mock_open:
mock_open.return_value.__enter__ = lambda s: s
mock_open.return_value.__exit__ = MagicMock(return_value=False)
mock_open.return_value.read = MagicMock(
return_value="12:memory:/docker/abc123\n"
)
assert _is_inside_container() is True
def test_is_inside_container_false_on_host():
"""Returns False when none of the container indicators are present."""
with patch("os.path.exists", return_value=False), \
patch("builtins.open", side_effect=OSError("no such file")):
assert _is_inside_container() is False
# =============================================================================
# get_container_exec_info
# =============================================================================
@pytest.fixture
def container_env(tmp_path, monkeypatch):
"""Set up a fake HERMES_HOME with .container-mode file."""
hermes_home = tmp_path / ".hermes"
hermes_home.mkdir()
monkeypatch.setenv("HERMES_HOME", str(hermes_home))
monkeypatch.delenv("HERMES_DEV", raising=False)
container_mode = hermes_home / ".container-mode"
container_mode.write_text(
"# Written by NixOS activation script. Do not edit manually.\n"
"backend=podman\n"
"container_name=hermes-agent\n"
"exec_user=hermes\n"
"hermes_bin=/data/current-package/bin/hermes\n"
)
return hermes_home
def test_get_container_exec_info_returns_metadata(container_env):
"""Reads .container-mode and returns all fields including exec_user."""
with patch("hermes_cli.config._is_inside_container", return_value=False):
info = get_container_exec_info()
assert info is not None
assert info["backend"] == "podman"
assert info["container_name"] == "hermes-agent"
assert info["exec_user"] == "hermes"
assert info["hermes_bin"] == "/data/current-package/bin/hermes"
def test_get_container_exec_info_none_inside_container(container_env):
"""Returns None when we're already inside a container."""
with patch("hermes_cli.config._is_inside_container", return_value=True):
info = get_container_exec_info()
assert info is None
def test_get_container_exec_info_none_without_file(tmp_path, monkeypatch):
"""Returns None when .container-mode doesn't exist (native mode)."""
hermes_home = tmp_path / ".hermes"
hermes_home.mkdir()
monkeypatch.setenv("HERMES_HOME", str(hermes_home))
monkeypatch.delenv("HERMES_DEV", raising=False)
with patch("hermes_cli.config._is_inside_container", return_value=False):
info = get_container_exec_info()
assert info is None
def test_get_container_exec_info_skipped_when_hermes_dev(container_env, monkeypatch):
"""Returns None when HERMES_DEV=1 is set (dev mode bypass)."""
monkeypatch.setenv("HERMES_DEV", "1")
with patch("hermes_cli.config._is_inside_container", return_value=False):
info = get_container_exec_info()
assert info is None
def test_get_container_exec_info_not_skipped_when_hermes_dev_zero(container_env, monkeypatch):
"""HERMES_DEV=0 does NOT trigger bypass — only '1' does."""
monkeypatch.setenv("HERMES_DEV", "0")
with patch("hermes_cli.config._is_inside_container", return_value=False):
info = get_container_exec_info()
assert info is not None
def test_get_container_exec_info_defaults():
"""Falls back to defaults for missing keys."""
import tempfile
with tempfile.TemporaryDirectory() as tmpdir:
hermes_home = Path(tmpdir) / ".hermes"
hermes_home.mkdir()
(hermes_home / ".container-mode").write_text(
"# minimal file with no keys\n"
)
with patch("hermes_cli.config._is_inside_container", return_value=False), \
patch("hermes_cli.config.get_hermes_home", return_value=hermes_home), \
patch.dict(os.environ, {}, clear=False):
os.environ.pop("HERMES_DEV", None)
info = get_container_exec_info()
assert info is not None
assert info["backend"] == "docker"
assert info["container_name"] == "hermes-agent"
assert info["exec_user"] == "hermes"
assert info["hermes_bin"] == "/data/current-package/bin/hermes"
def test_get_container_exec_info_docker_backend(container_env):
"""Correctly reads docker backend with custom exec_user."""
(container_env / ".container-mode").write_text(
"backend=docker\n"
"container_name=hermes-custom\n"
"exec_user=myuser\n"
"hermes_bin=/opt/hermes/bin/hermes\n"
)
with patch("hermes_cli.config._is_inside_container", return_value=False):
info = get_container_exec_info()
assert info["backend"] == "docker"
assert info["container_name"] == "hermes-custom"
assert info["exec_user"] == "myuser"
assert info["hermes_bin"] == "/opt/hermes/bin/hermes"
def test_get_container_exec_info_crashes_on_permission_error(container_env):
"""PermissionError propagates instead of being silently swallowed."""
with patch("hermes_cli.config._is_inside_container", return_value=False), \
patch("builtins.open", side_effect=PermissionError("permission denied")):
with pytest.raises(PermissionError):
get_container_exec_info()
# =============================================================================
# _exec_in_container
# =============================================================================
@pytest.fixture
def docker_container_info():
return {
"backend": "docker",
"container_name": "hermes-agent",
"exec_user": "hermes",
"hermes_bin": "/data/current-package/bin/hermes",
}
@pytest.fixture
def podman_container_info():
return {
"backend": "podman",
"container_name": "hermes-agent",
"exec_user": "hermes",
"hermes_bin": "/data/current-package/bin/hermes",
}
def test_exec_in_container_calls_execvp(docker_container_info):
"""Verifies os.execvp is called with correct args: runtime, tty flags,
user, env vars, container name, binary, and CLI args."""
from hermes_cli.main import _exec_in_container
with patch("shutil.which", return_value="/usr/bin/docker"), \
patch("subprocess.run") as mock_run, \
patch("sys.stdin") as mock_stdin, \
patch("os.execvp") as mock_execvp, \
patch.dict(os.environ, {"TERM": "xterm-256color", "LANG": "en_US.UTF-8"},
clear=False):
mock_stdin.isatty.return_value = True
mock_run.return_value = MagicMock(returncode=0)
_exec_in_container(docker_container_info, ["chat", "-m", "opus"])
mock_execvp.assert_called_once()
cmd = mock_execvp.call_args[0][1]
assert cmd[0] == "/usr/bin/docker"
assert cmd[1] == "exec"
assert "-it" in cmd
idx_u = cmd.index("-u")
assert cmd[idx_u + 1] == "hermes"
e_indices = [i for i, v in enumerate(cmd) if v == "-e"]
e_values = [cmd[i + 1] for i in e_indices]
assert "TERM=xterm-256color" in e_values
assert "LANG=en_US.UTF-8" in e_values
assert "hermes-agent" in cmd
assert "/data/current-package/bin/hermes" in cmd
assert "chat" in cmd
def test_exec_in_container_non_tty_uses_i_only(docker_container_info):
"""Non-TTY mode uses -i instead of -it."""
from hermes_cli.main import _exec_in_container
with patch("shutil.which", return_value="/usr/bin/docker"), \
patch("subprocess.run") as mock_run, \
patch("sys.stdin") as mock_stdin, \
patch("os.execvp") as mock_execvp:
mock_stdin.isatty.return_value = False
mock_run.return_value = MagicMock(returncode=0)
_exec_in_container(docker_container_info, ["sessions", "list"])
cmd = mock_execvp.call_args[0][1]
assert "-i" in cmd
assert "-it" not in cmd
def test_exec_in_container_no_runtime_hard_fails(podman_container_info):
"""Hard fails when runtime not found (no fallback)."""
from hermes_cli.main import _exec_in_container
with patch("shutil.which", return_value=None), \
patch("subprocess.run") as mock_run, \
patch("os.execvp") as mock_execvp, \
pytest.raises(SystemExit) as exc_info:
_exec_in_container(podman_container_info, ["chat"])
mock_run.assert_not_called()
mock_execvp.assert_not_called()
assert exc_info.value.code != 0
def test_exec_in_container_sudo_probe_sets_prefix(podman_container_info):
"""When first probe fails and sudo probe succeeds, execvp is called
with sudo -n prefix."""
from hermes_cli.main import _exec_in_container
def which_side_effect(name):
if name == "podman":
return "/usr/bin/podman"
if name == "sudo":
return "/usr/bin/sudo"
return None
with patch("shutil.which", side_effect=which_side_effect), \
patch("subprocess.run") as mock_run, \
patch("sys.stdin") as mock_stdin, \
patch("os.execvp") as mock_execvp:
mock_stdin.isatty.return_value = True
mock_run.side_effect = [
MagicMock(returncode=1), # direct probe fails
MagicMock(returncode=0), # sudo probe succeeds
]
_exec_in_container(podman_container_info, ["chat"])
mock_execvp.assert_called_once()
cmd = mock_execvp.call_args[0][1]
assert cmd[0] == "/usr/bin/sudo"
assert cmd[1] == "-n"
assert cmd[2] == "/usr/bin/podman"
assert cmd[3] == "exec"
def test_exec_in_container_probe_timeout_prints_message(docker_container_info):
"""TimeoutExpired from probe produces a human-readable error, not a
raw traceback."""
from hermes_cli.main import _exec_in_container
with patch("shutil.which", return_value="/usr/bin/docker"), \
patch("subprocess.run", side_effect=subprocess.TimeoutExpired(
cmd=["docker", "inspect"], timeout=15)), \
patch("os.execvp") as mock_execvp, \
pytest.raises(SystemExit) as exc_info:
_exec_in_container(docker_container_info, ["chat"])
mock_execvp.assert_not_called()
assert exc_info.value.code == 1
def test_exec_in_container_container_not_running_no_sudo(docker_container_info):
"""When runtime exists but container not found and no sudo available,
prints helpful error about root containers."""
from hermes_cli.main import _exec_in_container
def which_side_effect(name):
if name == "docker":
return "/usr/bin/docker"
return None
with patch("shutil.which", side_effect=which_side_effect), \
patch("subprocess.run") as mock_run, \
patch("os.execvp") as mock_execvp, \
pytest.raises(SystemExit) as exc_info:
mock_run.return_value = MagicMock(returncode=1)
_exec_in_container(docker_container_info, ["chat"])
mock_execvp.assert_not_called()
assert exc_info.value.code == 1