hermes-agent/tests/gateway/test_scale_to_zero_watcher.py
Ben Barclay dedf5643d8
fix(gateway): scale-to-zero never armed — arm-gate counted disabled placeholder platforms (#52831)
The scale-to-zero idle watcher never started on a correctly-opted-in,
relay-only instance, so the gateway never ran its idle decision, never called
go_dormant(), and never sent going_idle to the connector. Fly's autostop still
suspended the machine on traffic-idle, but the connector never flipped the
instance to buffered-only — so an inbound DM took the live delivery path,
found no live session for the suspended machine, and was dropped fail-closed
with no wake poke. The machine slept and never woke.

Root cause: _scale_to_zero_should_arm() passed list(config.platforms.keys())
to messaging_is_relay_only_or_absent(). config.platforms is pre-seeded with a
DISABLED placeholder PlatformConfig for every known platform (telegram,
discord, slack, matrix, …), so the key set is always the full ~20-entry
catalog regardless of what the instance actually runs. The relay-only check
discarded "relay", saw the disabled placeholders as live direct-socket
platforms, and returned False — so should_arm() was False and the watcher was
never created. Verified live on a staging instance: config.platforms keys =
[telegram, discord, slack, mattermost, matrix, relay] with only relay
enabled=True; should_arm() = False.

Fix: filter config.platforms to ENABLED entries before the relay-only check,
mirroring the adapter-connect loop which already gates on
`if not platform_config.enabled: continue`. This arms off the same notion of
"active platform" the rest of start() already uses — no parallel concept.

Also add a one-line not-armed diagnostic: when an instance IS opted in (the
HERMES_SCALE_TO_ZERO stamp is set) but the watcher still doesn't arm, log why
(relay_only_or_absent, the enabled platforms, wake_url present/missing). A
non-opted instance stays silent. The arm path previously logged only on
success, so a failed arm was invisible.

Tests: the existing pure-helper tests passed bare names so they never
exercised the call site that feeds the placeholder-laden config. Add
behaviour-contract tests against the REAL _scale_to_zero_should_arm with a
realistic config.platforms (relay enabled + others disabled). The F25
regression test (relay-only + disabled placeholders must arm) and the
no-platform case are RED without this fix, GREEN with it; the
genuinely-enabled-direct-platform / not-opted-in / no-wake-url cases stay
correctly non-arming so the filter can't over-broaden.

Wake mechanism itself verified healthy independently (direct wakeUrl GET
resumed a suspended staging instance in 1.15s, clean resume signature).
2026-06-26 14:01:48 +10:00

237 lines
9 KiB
Python

"""Watcher-level tests for scale-to-zero: the idle watcher's dormant sequence and
the arm-gate wiring, exercised against the real GatewayRunner methods bound onto
a lightweight stand-in (booting a full gateway is unnecessary for this logic and
would be slow/flaky).
These cover the parts gateway/test_scale_to_zero.py (pure helpers) can't: that
the watcher calls the relay adapter's go_dormant() exactly when idle+armed,
respects the cooldown, and skips when busy — the F7/D3 + D12 behaviour.
"""
from __future__ import annotations
import asyncio
import time
import pytest
from gateway.run import GatewayRunner
class _FakeRelayAdapter:
def __init__(self):
self.go_dormant_calls = 0
async def go_dormant(self):
self.go_dormant_calls += 1
return True
def _runner_with(monkeypatch, *, idle, armed_adapter=True):
"""Build a GatewayRunner without booting it, stubbing just what the watcher
touches. Real methods (_scale_to_zero_is_idle composition, the watcher body)
run; only their dependencies are stubbed."""
r = GatewayRunner.__new__(GatewayRunner)
r._running = True
r._scale_to_zero_cooldown_until = 0.0
r._last_inbound_at = time.time()
r._running_agents = {}
r._background_tasks = set()
adapter = _FakeRelayAdapter() if armed_adapter else None
monkeypatch.setattr(r, "_scale_to_zero_is_idle", lambda: idle, raising=False)
monkeypatch.setattr(r, "_relay_adapter_for_dormancy", lambda: adapter, raising=False)
monkeypatch.setattr(r, "_scale_to_zero_idle_timeout_seconds", lambda: 300.0, raising=False)
monkeypatch.setattr(r, "_update_runtime_status", lambda *a, **k: None, raising=False)
return r, adapter
@pytest.mark.asyncio
async def test_watcher_goes_dormant_when_idle(monkeypatch):
r, adapter = _runner_with(monkeypatch, idle=True)
# Run one iteration: stop after the first sleep so the loop exits cleanly.
task = asyncio.create_task(r._scale_to_zero_watcher(interval=0.01))
await asyncio.sleep(0.1)
r._running = False
await asyncio.wait_for(task, timeout=2)
assert adapter.go_dormant_calls >= 1
# After driving dormant, a re-arm cooldown is set (0.F).
assert r._scale_to_zero_cooldown_until > time.time()
@pytest.mark.asyncio
async def test_watcher_does_not_go_dormant_when_busy(monkeypatch):
r, adapter = _runner_with(monkeypatch, idle=False)
task = asyncio.create_task(r._scale_to_zero_watcher(interval=0.01))
await asyncio.sleep(0.1)
r._running = False
await asyncio.wait_for(task, timeout=2)
assert adapter.go_dormant_calls == 0
@pytest.mark.asyncio
async def test_watcher_respects_cooldown(monkeypatch):
r, adapter = _runner_with(monkeypatch, idle=True)
# Cooldown active far in the future: even though idle, no dormancy fires.
r._scale_to_zero_cooldown_until = time.time() + 3600
task = asyncio.create_task(r._scale_to_zero_watcher(interval=0.01))
await asyncio.sleep(0.1)
r._running = False
await asyncio.wait_for(task, timeout=2)
assert adapter.go_dormant_calls == 0
@pytest.mark.asyncio
async def test_watcher_noop_when_no_relay_adapter(monkeypatch):
# Armed-but-no-relay-adapter (e.g. relay not yet connected): must not crash.
r, _ = _runner_with(monkeypatch, idle=True, armed_adapter=False)
task = asyncio.create_task(r._scale_to_zero_watcher(interval=0.01))
await asyncio.sleep(0.1)
r._running = False
await asyncio.wait_for(task, timeout=2)
# No exception, loop exits cleanly — nothing to assert beyond survival.
def test_bg_work_blocks_idle_via_background_tasks(monkeypatch):
"""_scale_to_zero_has_live_background_work() reports True when a tracked
background task is still live (D3/F7) — the guard that keeps a gateway with
an in-flight backgrounded subagent/terminal awake."""
r = GatewayRunner.__new__(GatewayRunner)
async def _never():
await asyncio.sleep(3600)
loop = asyncio.new_event_loop()
try:
t = loop.create_task(_never())
r._background_tasks = {t}
# process_registry has nothing active in this fresh process.
assert r._scale_to_zero_has_live_background_work() is True
t.cancel()
finally:
loop.run_until_complete(asyncio.gather(t, return_exceptions=True))
loop.close()
def test_bg_work_blocks_idle_via_async_delegation(monkeypatch):
"""delegate_task(background=true) lives in tools.async_delegation, not the
process registry. An active background delegation must block suspend too."""
r = GatewayRunner.__new__(GatewayRunner)
r._background_tasks = set()
monkeypatch.setattr("tools.async_delegation.active_count", lambda: 1)
assert r._scale_to_zero_has_live_background_work() is True
def test_real_inbound_after_dormancy_restores_running_status(monkeypatch):
"""Once a dormant gateway receives real inbound after wake, the runtime
lifecycle must not remain stuck in the watcher-written `draining` state."""
r = GatewayRunner.__new__(GatewayRunner)
r._last_inbound_at = 0.0
r._scale_to_zero_cooldown_until = time.time() + 60.0
status_updates = []
monkeypatch.setattr(
r,
"_update_runtime_status",
lambda state=None, *a, **k: status_updates.append(state),
raising=False,
)
r._scale_to_zero_note_real_inbound()
assert r._last_inbound_at > 0.0
assert status_updates == ["running"]
def test_bg_work_false_when_quiet():
r = GatewayRunner.__new__(GatewayRunner)
r._background_tasks = set()
# No background tasks, no active processes in this fresh process.
assert r._scale_to_zero_has_live_background_work() is False
# ── _scale_to_zero_should_arm: the CALL SITE feeds config.platforms (the F25 bug) ──
#
# config.platforms is pre-seeded with a DISABLED placeholder PlatformConfig for every
# known platform, so list(config.platforms.keys()) is always the full ~20-entry catalog
# regardless of what the instance runs. The arm check must filter to ENABLED platforms
# (mirroring the connect loop) before asking messaging_is_relay_only_or_absent — passing
# the bare placeholder keys made it see disabled `discord`/`telegram`/… as live direct
# platforms and refuse to arm on a real relay-only instance. The pure-helper tests in
# test_scale_to_zero.py pass bare names so they never exercised this call site.
def _arm_runner(monkeypatch, platform_states, *, enabled=True, wake_url="https://wake.example"):
"""Build a GatewayRunner stand-in whose config.platforms mirrors a real load:
`platform_states` is {Platform: enabled_bool}; everything runs the REAL
_scale_to_zero_should_arm. Only the env flag + wake_url resolution are stubbed."""
from types import SimpleNamespace
from gateway.config import PlatformConfig
r = GatewayRunner.__new__(GatewayRunner)
platforms = {p: PlatformConfig(enabled=en) for p, en in platform_states.items()}
r.config = SimpleNamespace(platforms=platforms)
monkeypatch.setattr("gateway.scale_to_zero.scale_to_zero_enabled", lambda *a, **k: enabled)
monkeypatch.setattr("gateway.relay.relay_wake_url", lambda: wake_url)
return r
def test_arm_true_for_relay_only_with_disabled_placeholders(monkeypatch):
"""The F25 regression test: relay ENABLED, every other platform present but
DISABLED (the real load_gateway_config() shape). Must arm — the disabled
placeholders must NOT count as live direct-socket platforms."""
from gateway.platforms.base import Platform
r = _arm_runner(
monkeypatch,
{
Platform.TELEGRAM: False,
Platform.DISCORD: False,
Platform.SLACK: False,
Platform.MATRIX: False,
Platform.RELAY: True,
},
)
assert r._scale_to_zero_should_arm() is True
def test_no_arm_when_a_direct_platform_is_actually_enabled(monkeypatch):
"""A genuinely-enabled direct-socket platform (real Discord token) DOES disarm —
the filter must not over-broaden to 'ignore everything but relay'."""
from gateway.platforms.base import Platform
r = _arm_runner(
monkeypatch,
{Platform.DISCORD: True, Platform.RELAY: True},
)
assert r._scale_to_zero_should_arm() is False
def test_arm_when_no_platform_enabled_at_all(monkeypatch):
"""Chronos-only / no-messaging agent (all placeholders disabled) can scale to zero."""
from gateway.platforms.base import Platform
r = _arm_runner(
monkeypatch,
{Platform.TELEGRAM: False, Platform.DISCORD: False},
)
assert r._scale_to_zero_should_arm() is True
def test_no_arm_when_not_opted_in(monkeypatch):
"""Relay-only but the Labs stamp is off ⇒ never arm (fail-safe default)."""
from gateway.platforms.base import Platform
r = _arm_runner(monkeypatch, {Platform.RELAY: True}, enabled=False)
assert r._scale_to_zero_should_arm() is False
def test_no_arm_without_wake_url(monkeypatch):
"""Relay-only + opted in but no registered wake URL ⇒ no arm (§3.4(1))."""
from gateway.platforms.base import Platform
r = _arm_runner(monkeypatch, {Platform.RELAY: True}, wake_url=None)
assert r._scale_to_zero_should_arm() is False