Files
Shadowbroker/backend/tests/test_aishub_fallback.py
T
BigBodyCobain a2f5d62926 feat(ais): AISHub REST fallback when AISStream WebSocket is offline
When stream.aisstream.io is unreachable (cert outage, server down — see
2026-05-20 and 2026-05-23 events) the ships layer goes empty. This adds
a slow REST fallback to data.aishub.net so the layer stays populated in
degraded mode.

Behavior:

* Opt-in via AISHUB_USERNAME (free registration at aishub.net/api).
  Without the env var the fetcher is a no-op.
* Default poll cadence 20 min — well inside their free-tier limits, gives
  ships time to move enough to look "alive". Configurable via
  AISHUB_POLL_INTERVAL_MINUTES, clamped to [1, 360].
* Internal gate: skips the poll entirely when the WebSocket primary is
  currently connected. Stomping fresh live data with 20-min-old REST
  data would be worse than leaving it alone.
* Vessels merge into the shared _vessels dict with source="aishub" so
  the existing UI / health tooling can attribute the provider.
* Live data wins races: if a WebSocket update for the same MMSI lands in
  the last 1s, we don't overwrite with the slower REST record.

Scheduler job runs every AISHUB_POLL_INTERVAL_MINUTES minutes alongside
the existing ais_prune job in data_fetcher.py.

24 tests cover gating (no-username, primary-connected), response parsing
(success / error / empty / malformed / unexpected shape), record
normalization (sentinels, missing fields, range checks, AIS @ padding),
poll interval clamping, and end-to-end merge with live-data-wins.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-23 07:00:32 -06:00

433 lines
16 KiB
Python

"""AISHub REST fallback for ship tracking.
Background
----------
When ``stream.aisstream.io`` (the WebSocket primary) is unreachable, the
ships layer goes empty. ``aishub_fallback.py`` polls ``data.aishub.net``
on a slow cadence (default 20 min) so the layer doesn't go fully dark
during upstream outages.
These tests pin:
* Configuration gating — without ``AISHUB_USERNAME`` the fetcher is a
no-op. The username's presence is the opt-in.
* Connectivity gating — when the WebSocket primary is connected, the
fallback skips so it doesn't stomp fresher live data.
* Response parsing — successful, error, and empty AISHub payloads.
* Record normalization — bad records (no MMSI, sentinel positions) are
dropped without crashing.
* Merge behavior — records land in the shared ``_vessels`` dict with
``source: "aishub"`` and don't overwrite very-recent live updates.
* Poll interval clamping — env var overrides honored within [1, 360].
"""
from __future__ import annotations
import json
import os
import time
import pytest
# ---------------------------------------------------------------------------
# Configuration / gating
# ---------------------------------------------------------------------------
class TestGating:
def test_no_username_means_disabled(self, monkeypatch):
from services.fetchers.aishub_fallback import (
aishub_fallback_enabled,
fetch_aishub_vessels,
)
monkeypatch.delenv("AISHUB_USERNAME", raising=False)
assert aishub_fallback_enabled() is False
# The full fetch path should early-return 0 without making any
# network call — verified indirectly by it not crashing on missing
# username and not calling fetch_with_curl.
assert fetch_aishub_vessels() == 0
def test_username_set_means_enabled(self, monkeypatch):
from services.fetchers.aishub_fallback import aishub_fallback_enabled
monkeypatch.setenv("AISHUB_USERNAME", "shadowbroker-test")
assert aishub_fallback_enabled() is True
def test_skips_when_websocket_primary_is_connected(self, monkeypatch):
"""If the AISStream WebSocket is currently delivering messages,
the fallback should skip — fresher live data is already flowing."""
from services.fetchers import aishub_fallback
from services import ais_stream as ais
monkeypatch.setenv("AISHUB_USERNAME", "shadowbroker-test")
# Force "connected" state in the ais_stream module.
with ais._vessels_lock:
ais._last_msg_at = time.time() - 5 # 5s ago — well inside 60s
ais._proxy_spawn_count = 1
# Sanity check the gate:
assert ais.ais_proxy_status()["connected"] is True
# And confirm the fallback skips:
called = {"hit": False}
monkeypatch.setattr(
aishub_fallback,
"fetch_with_curl",
lambda *a, **kw: (_ for _ in ()).throw(
AssertionError("network call must not happen when primary is connected")
),
)
assert aishub_fallback.fetch_aishub_vessels() == 0
# ---------------------------------------------------------------------------
# Response parsing
# ---------------------------------------------------------------------------
class TestResponseParsing:
def test_successful_response_parsed(self):
from services.fetchers.aishub_fallback import _parse_aishub_response
payload = json.dumps([
{"ERROR": False, "USERNAME": "test", "FORMAT": "1", "RECORDS": 2},
[
{"MMSI": 123, "LATITUDE": 40.0, "LONGITUDE": -73.0},
{"MMSI": 456, "LATITUDE": 51.5, "LONGITUDE": -0.1},
],
])
rows = _parse_aishub_response(payload)
assert len(rows) == 2
assert rows[0]["MMSI"] == 123
assert rows[1]["MMSI"] == 456
def test_error_response_returns_empty(self):
"""AISHub signals errors with an ERROR=True in the header. We log
and treat as no data."""
from services.fetchers.aishub_fallback import _parse_aishub_response
payload = json.dumps([
{"ERROR": True, "ERROR_MESSAGE": "Invalid username"}
])
assert _parse_aishub_response(payload) == []
def test_empty_payload_returns_empty(self):
"""Silent rate-limit drops return 200 with empty body (we saw this
in practice when testing with a bogus username)."""
from services.fetchers.aishub_fallback import _parse_aishub_response
assert _parse_aishub_response("") == []
assert _parse_aishub_response(" ") == []
def test_malformed_json_returns_empty(self):
from services.fetchers.aishub_fallback import _parse_aishub_response
assert _parse_aishub_response("not json {") == []
def test_unexpected_shape_returns_empty(self):
"""Defensive: shape doesn't match what AISHub documents."""
from services.fetchers.aishub_fallback import _parse_aishub_response
assert _parse_aishub_response(json.dumps({"unexpected": "object"})) == []
assert _parse_aishub_response(json.dumps([])) == []
# Header-only with no records list:
assert _parse_aishub_response(json.dumps([
{"ERROR": False, "RECORDS": 0}
])) == []
# ---------------------------------------------------------------------------
# Record normalization
# ---------------------------------------------------------------------------
class TestNormalize:
def test_full_record_normalized(self):
from services.fetchers.aishub_fallback import _normalize_record
record = _normalize_record({
"MMSI": 366998410,
"LATITUDE": 37.8,
"LONGITUDE": -122.4,
"COG": 280,
"SOG": 12.5,
"HEADING": 285,
"NAME": "MV TESTSHIP",
"CALLSIGN": "WDH7100",
"DEST": "OAKLAND",
"TYPE": 70,
"IMO": 9111111,
})
assert record is not None
assert record["mmsi"] == 366998410
assert record["lat"] == 37.8
assert record["lng"] == -122.4
assert record["sog"] == 12.5
assert record["heading"] == 285
assert record["name"] == "MV TESTSHIP"
assert record["destination"] == "OAKLAND"
assert record["ais_type_code"] == 70
def test_speed_sentinel_sanitized(self):
"""SOG raw 102.3+ kn = "speed not available" in the AIS spec.
Sanitize to 0 so it doesn't look like a 200-knot ship."""
from services.fetchers.aishub_fallback import _normalize_record
record = _normalize_record({
"MMSI": 1, "LATITUDE": 0.5, "LONGITUDE": 0.5,
"SOG": 102.3, "COG": 0,
})
assert record["sog"] == 0.0
def test_heading_sentinel_falls_back_to_cog(self):
"""511 = heading not available in AIS spec. Use COG instead."""
from services.fetchers.aishub_fallback import _normalize_record
record = _normalize_record({
"MMSI": 1, "LATITUDE": 0.5, "LONGITUDE": 0.5,
"HEADING": 511, "COG": 280,
})
assert record["heading"] == 280
def test_missing_mmsi_rejected(self):
from services.fetchers.aishub_fallback import _normalize_record
assert _normalize_record({"LATITUDE": 0.5, "LONGITUDE": 0.5}) is None
assert _normalize_record({"MMSI": 0, "LATITUDE": 0.5, "LONGITUDE": 0.5}) is None
def test_no_position_rejected(self):
from services.fetchers.aishub_fallback import _normalize_record
assert _normalize_record({"MMSI": 1}) is None
assert _normalize_record({"MMSI": 1, "LATITUDE": 0.5}) is None
assert _normalize_record({"MMSI": 1, "LONGITUDE": 0.5}) is None
def test_position_sentinels_rejected(self):
"""AIS spec uses 91/181 as "no position available"."""
from services.fetchers.aishub_fallback import _normalize_record
assert _normalize_record({
"MMSI": 1, "LATITUDE": 91.0, "LONGITUDE": 0.0
}) is None
assert _normalize_record({
"MMSI": 1, "LATITUDE": 0.0, "LONGITUDE": 181.0
}) is None
def test_out_of_range_rejected(self):
from services.fetchers.aishub_fallback import _normalize_record
assert _normalize_record({
"MMSI": 1, "LATITUDE": 95.0, "LONGITUDE": 0.0
}) is None
assert _normalize_record({
"MMSI": 1, "LATITUDE": 0.0, "LONGITUDE": 200.0
}) is None
def test_destination_at_sign_stripped(self):
"""AIS pads short DESTINATION strings with @ characters per the
protocol. Strip them so the UI doesn't render "OAKLAND@@@@@"."""
from services.fetchers.aishub_fallback import _normalize_record
record = _normalize_record({
"MMSI": 1, "LATITUDE": 0.5, "LONGITUDE": 0.5,
"DEST": "OAKLAND@@@",
})
assert record["destination"] == "OAKLAND"
# ---------------------------------------------------------------------------
# Poll interval clamping
# ---------------------------------------------------------------------------
class TestPollInterval:
def test_default_is_twenty_minutes(self, monkeypatch):
from services.fetchers.aishub_fallback import aishub_poll_interval_minutes
monkeypatch.delenv("AISHUB_POLL_INTERVAL_MINUTES", raising=False)
assert aishub_poll_interval_minutes() == 20
def test_env_override_honored(self, monkeypatch):
from services.fetchers.aishub_fallback import aishub_poll_interval_minutes
monkeypatch.setenv("AISHUB_POLL_INTERVAL_MINUTES", "45")
assert aishub_poll_interval_minutes() == 45
def test_clamp_lower_bound(self, monkeypatch):
"""A 0 or negative env var would hammer the upstream — clamp."""
from services.fetchers.aishub_fallback import aishub_poll_interval_minutes
monkeypatch.setenv("AISHUB_POLL_INTERVAL_MINUTES", "0")
assert aishub_poll_interval_minutes() == 1
monkeypatch.setenv("AISHUB_POLL_INTERVAL_MINUTES", "-5")
assert aishub_poll_interval_minutes() == 1
def test_clamp_upper_bound(self, monkeypatch):
"""A 99999 env var would silence the fallback effectively forever."""
from services.fetchers.aishub_fallback import aishub_poll_interval_minutes
monkeypatch.setenv("AISHUB_POLL_INTERVAL_MINUTES", "99999")
assert aishub_poll_interval_minutes() == 360
def test_malformed_env_defaults(self, monkeypatch):
from services.fetchers.aishub_fallback import aishub_poll_interval_minutes
monkeypatch.setenv("AISHUB_POLL_INTERVAL_MINUTES", "twenty")
assert aishub_poll_interval_minutes() == 20
# ---------------------------------------------------------------------------
# End-to-end fetch + merge into _vessels store
# ---------------------------------------------------------------------------
class TestFetchAndMerge:
def _force_primary_disconnected(self):
"""Set ais_stream module state so the gate allows the fallback."""
from services import ais_stream as ais
with ais._vessels_lock:
# Far in the past → connected = false; spawn_count > 0 → primary
# has at least tried so the gate engages.
ais._last_msg_at = time.time() - 3600
ais._proxy_spawn_count = 5
ais._vessels.clear()
def test_vessels_merged_with_source_tag(self, monkeypatch):
"""Happy path: AISHub returns 2 ships, both land in ``_vessels``
with ``source: 'aishub'``."""
from services.fetchers import aishub_fallback
from services import ais_stream as ais
monkeypatch.setenv("AISHUB_USERNAME", "test-user")
self._force_primary_disconnected()
payload = json.dumps([
{"ERROR": False, "USERNAME": "test-user", "FORMAT": "1", "RECORDS": 2},
[
{
"MMSI": 111111111,
"LATITUDE": 40.0,
"LONGITUDE": -73.0,
"SOG": 12.0,
"COG": 270,
"HEADING": 275,
"NAME": "SHIP A",
"TYPE": 70,
},
{
"MMSI": 222222222,
"LATITUDE": 51.5,
"LONGITUDE": -0.1,
"SOG": 8.0,
"COG": 90,
"HEADING": 92,
"NAME": "SHIP B",
"TYPE": 60,
},
],
])
class FakeResp:
status_code = 200
text = payload
monkeypatch.setattr(
aishub_fallback, "fetch_with_curl", lambda *a, **kw: FakeResp()
)
count = aishub_fallback.fetch_aishub_vessels()
assert count == 2
with ais._vessels_lock:
v1 = ais._vessels.get(111111111)
v2 = ais._vessels.get(222222222)
assert v1 is not None
assert v1["source"] == "aishub"
assert v1["lat"] == 40.0
assert v1["name"] == "SHIP A"
assert v2 is not None
assert v2["source"] == "aishub"
assert v2["type"] == "passenger" # AIS type 60 → passenger
def test_does_not_overwrite_fresh_live_data(self, monkeypatch):
"""If the WebSocket pushed an update for an MMSI 0.5s ago and the
AISHub poll completes in that window, we should NOT clobber the
fresher live data."""
from services.fetchers import aishub_fallback
from services import ais_stream as ais
monkeypatch.setenv("AISHUB_USERNAME", "test-user")
self._force_primary_disconnected()
# Pre-seed _vessels with a "very fresh" live record.
fresh_ts = time.time()
with ais._vessels_lock:
ais._vessels[111111111] = {
"mmsi": 111111111,
"lat": 12.34,
"lng": 56.78,
"source": "aisstream",
"_updated": fresh_ts,
}
payload = json.dumps([
{"ERROR": False, "USERNAME": "test-user", "FORMAT": "1", "RECORDS": 1},
[
{
"MMSI": 111111111,
"LATITUDE": 99.0, # bogus to make the test obvious
"LONGITUDE": 99.0,
"NAME": "STALE",
"SOG": 0,
"COG": 0,
"TYPE": 0,
},
],
])
class FakeResp:
status_code = 200
text = payload
monkeypatch.setattr(
aishub_fallback, "fetch_with_curl", lambda *a, **kw: FakeResp()
)
# Note: 99.0/99.0 also exceeds the 91/181 sentinel guard and
# would be filtered. Pick a valid-but-bogus position instead.
payload = json.dumps([
{"ERROR": False, "USERNAME": "test-user", "FORMAT": "1", "RECORDS": 1},
[
{
"MMSI": 111111111,
"LATITUDE": 0.0, # different from the live 12.34
"LONGITUDE": 0.0,
"NAME": "STALE",
"SOG": 0,
"COG": 0,
"TYPE": 0,
},
],
])
monkeypatch.setattr(
aishub_fallback, "fetch_with_curl",
lambda *a, **kw: type("R", (), {"status_code": 200, "text": payload})(),
)
aishub_fallback.fetch_aishub_vessels()
with ais._vessels_lock:
v = ais._vessels.get(111111111)
# Live data wins — position should still be 12.34 / 56.78.
assert v["lat"] == 12.34
assert v["lng"] == 56.78
assert v["source"] == "aisstream"
def test_http_failure_returns_zero(self, monkeypatch):
from services.fetchers import aishub_fallback
monkeypatch.setenv("AISHUB_USERNAME", "test-user")
self._force_primary_disconnected()
class FailResp:
status_code = 503
text = ""
monkeypatch.setattr(
aishub_fallback, "fetch_with_curl", lambda *a, **kw: FailResp()
)
assert aishub_fallback.fetch_aishub_vessels() == 0