Files
bot-bottle/bot_bottle/policy_resolver.py
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didericis 47268f6fd6 feat(orchestrator+egress): slice 8 — multi-tenant egress via the resolver (#352)
The egress addon now selects each request's Config by the calling bottle's
source IP, so one shared sidecar serves every bottle. Opt-in and fail-closed;
single-tenant behaviour is unchanged.

Orchestrator side (source-IP-primary attribution, per the PRD invariant):
  * registry: `by_source_ip` (the single active bottle at a source IP —
    network-layer attribution); `attribute` now composes it + the token.
  * service: `resolve(source_ip, token="")` — with a token, strict
    attribution; without, source IP alone.
  * control_plane: `POST /resolve`'s identity_token is now OPTIONAL (absent
    → source-IP-only); split cleanly from the token-required `/attribute`.
  * policy_resolver: `resolve` token now optional.

Egress side:
  * egress_addon_core: `resolve_client_config(resolver, client_ip, token)` —
    fetches + parses the client's Config, **fail-closed**: unattributed, a
    resolver error, or an unparseable policy all yield deny-all (no routes).
    Host-testable; `PolicyResolverLike` Protocol keeps it import-free.
  * egress_addon: consolidated mode when `BOT_BOTTLE_ORCHESTRATOR_URL` is
    set → `_active_config(flow)` resolves per client IP (reads + strips the
    `x-bot-bottle-identity` header); `request()` uses it. Unset → the static
    routes file, exactly as before. `PolicyResolver` added to the bundle.

Security note: source-IP-only resolution is safe where the IP is unspoofable
(Firecracker /31 + nft) AND the control plane is reachable only by the
trusted sidecar; the identity token, when the agent injects it, strengthens
it on weaker backends.

Scope note: the egress data plane is now multi-tenant. Remaining to be fully
live: the network topology routing every bottle's proxy to the one shared
sidecar, git-gate multitenancy, and agent-side identity-token injection.

Tests: registry by_source_ip; orchestrator resolve (with/without token);
control-plane /resolve token-optional; resolver token-optional;
resolve_client_config fail-closed matrix. All 182 egress tests still pass
(single-tenant unchanged). Full suite green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WBMWTEtQdJ4W5UrWuLHCck
2026-07-14 01:28:32 -04:00

77 lines
3.4 KiB
Python

"""Sidecar-side per-client policy resolver (PRD 0070).
The consolidated sidecar serves every bottle from one process, so for each
request it must apply the *calling* bottle's policy, selected by the source
IP the attribution invariant makes unspoofable. This resolves that policy
from the orchestrator's control plane (`POST /resolve`), keyed on the
`(source_ip, identity_token)` pair.
**Always fresh — no cache.** The resolver is called rarely enough that a
round-trip doesn't matter, and correctness matters more than speed: every
resolve reflects the orchestrator's *current* view, so a revocation, a
policy change, or a bottle teardown the orchestrator knows about is honored
immediately rather than lingering for a cache TTL. (If this ever becomes a
hot path, add caching with orchestrator-driven invalidation — not a blind
TTL.)
**Fail-closed:** an unattributed client (the orchestrator answers `403`)
resolves to `None`, and the caller (the egress addon, git-gate) must then
deny — exactly as an unknown bottle should be treated. Orchestrator
*errors* (unreachable / unexpected status) raise, so the caller can fail
closed too rather than silently serving stale or empty policy.
The resolved value is the policy blob the orchestrator stores verbatim; the
consumer parses it (e.g. the egress addon's `load_config`). This module is
stdlib-only and free of bot-bottle imports so it can be COPYed flat into
the sidecar bundle.
"""
from __future__ import annotations
import json
import urllib.error
import urllib.request
DEFAULT_TIMEOUT_SECONDS = 2.0
class PolicyResolveError(RuntimeError):
"""The orchestrator was unreachable or returned an unexpected status —
distinct from a clean `403` (unattributed), which returns None."""
class PolicyResolver:
"""Resolves each client's policy from the orchestrator, fresh per call."""
def __init__(self, base_url: str, *, timeout: float = DEFAULT_TIMEOUT_SECONDS) -> None:
self._base = base_url.rstrip("/")
self._timeout = timeout
def resolve(self, source_ip: str, identity_token: str = "") -> str | None:
"""The calling bottle's policy blob, or None if unattributed. Always
fetches from the orchestrator so revocations / changes / teardowns
are honored immediately. `identity_token` is optional — omit it to
resolve by source IP alone (the network-layer attribution).
Raises `PolicyResolveError` if the orchestrator can't be reached."""
body = json.dumps(
{"source_ip": source_ip, "identity_token": identity_token}
).encode()
req = urllib.request.Request(
f"{self._base}/resolve", data=body, method="POST",
headers={"Content-Type": "application/json"},
)
try:
with urllib.request.urlopen(req, timeout=self._timeout) as resp:
payload = json.loads(resp.read())
except urllib.error.HTTPError as e:
if e.code == 403:
return None # unattributed → fail closed (caller denies)
raise PolicyResolveError(f"/resolve returned HTTP {e.code}") from e
except (urllib.error.URLError, TimeoutError, OSError, ValueError) as e:
raise PolicyResolveError(f"/resolve unreachable or malformed: {e}") from e
policy = payload.get("policy") if isinstance(payload, dict) else None
return policy if isinstance(policy, str) else ""
__all__ = ["PolicyResolver", "PolicyResolveError"]