Files
DECNET/decnet/cli/gating.py
anti e6127a81a1 feat(webhook): worker + CLI + systemd unit
Introduces the `decnet webhook` long-running worker that consumes the
internal bus and POSTs matching events to configured subscriptions.

Design: one task per (subscription, pattern) pair. Each task opens
its own bus subscription, iterates events, and dispatches via the
shared deliver() client. No intermediate queue, no in-memory filter
matching — the bus's own pattern matcher is the filter. Reloads on
`system.webhook.subscriptions_changed` signals from the CRUD router,
with a 60s fallback timer in case a signal is lost.

Shutdown propagates via CancelledError on the outer task; all inner
subscription tasks are cancelled and awaited in a finally block.
Bus unavailable → worker stays up in idle mode per the DEBT-031
pattern, logging one warning.

Registered as a master-only CLI command (agents don't configure
webhooks — the subscription store lives on master). systemd unit
mirrors the profiler template; added to decnet.target Wants= list so
`systemctl start decnet.target` brings it up alongside everything
else. `decnet init` auto-picks up the new .service.j2 via its
existing `glob("decnet-*.service.j2")` sweep.
2026-04-24 15:46:11 -04:00

72 lines
2.8 KiB
Python

"""Role-based CLI gating.
MAINTAINERS: when you add a new Typer command (or add_typer group) that is
master-only, register its name in MASTER_ONLY_COMMANDS / MASTER_ONLY_GROUPS
below. The gate is the only thing that:
(a) hides the command from `decnet --help` on worker hosts, and
(b) prevents a misconfigured worker from invoking master-side logic.
Forgetting to register a new command is a role-boundary bug. Grep for
MASTER_ONLY when touching command registration.
Worker-legitimate commands (NOT in these sets): agent, updater, forwarder,
status, collect, probe, sniffer. Agents run deckies locally and should be
able to inspect them + run the per-host microservices (collector streams
container logs, prober characterizes attackers hitting this host, sniffer
captures traffic). Mutator and Profiler stay master-only: the mutator
orchestrates respawns across the swarm; the profiler rebuilds attacker
profiles against the master DB (no per-host DB exists).
"""
from __future__ import annotations
import os
import typer
from .utils import console
MASTER_ONLY_COMMANDS: frozenset[str] = frozenset({
"api", "swarmctl", "deploy", "redeploy", "teardown",
"mutate", "listener", "profiler",
"services", "distros", "correlate", "archetypes", "web",
"db-reset", "init", "webhook",
})
MASTER_ONLY_GROUPS: frozenset[str] = frozenset({"swarm", "topology", "geoip"})
def _agent_mode_active() -> bool:
"""True when the host is configured as an agent AND master commands are
disallowed (the default for agents). Workers overriding this explicitly
set DECNET_DISALLOW_MASTER=false to opt into hybrid use."""
mode = os.environ.get("DECNET_MODE", "master").lower()
disallow = os.environ.get("DECNET_DISALLOW_MASTER", "true").lower() == "true"
return mode == "agent" and disallow
def _require_master_mode(command_name: str) -> None:
"""Defence-in-depth: called at the top of every master-only command body.
The registration-time gate in _gate_commands_by_mode() already hides
these commands from Typer's dispatch table, but this check protects
against direct function imports (e.g. from tests or third-party tools)
that would bypass Typer entirely."""
if _agent_mode_active():
console.print(
f"[red]`decnet {command_name}` is a master-only command; this host "
f"is configured as an agent (DECNET_MODE=agent).[/]"
)
raise typer.Exit(1)
def _gate_commands_by_mode(_app: typer.Typer) -> None:
if not _agent_mode_active():
return
_app.registered_commands = [
c for c in _app.registered_commands
if (c.name or c.callback.__name__) not in MASTER_ONLY_COMMANDS
]
_app.registered_groups = [
g for g in _app.registered_groups
if g.name not in MASTER_ONLY_GROUPS
]