The headline implementation for issue #160. POST /api/query now gates
direct `bq."<dataset>"."<source_table>"` references behind the registry
and bounds the BQ scan cost behind a configurable cap. Wired through
the same singleton QuotaTracker as /api/v2/scan so daily-byte budgets
are shared across both BQ-touching paths.
Changes in app/api/query.py:
- Add module-level `BQ_PATH` regex matching the 16 syntax variants
verified empirically (fully-quoted, unquoted, mixed quoting,
case-insensitive, inside CTE bodies, multi-path, …).
- Add `bigquery_query` to the SQL keyword blocklist. Closes the
pre-existing function-call backdoor where a user could run an
arbitrary BQ jobs API call against any reachable dataset, bypassing
the registry and RBAC. Wrap views internal to the BQ extractor still
use bigquery_query() — but those run via DuckDB view resolution at
query time, not via user-submitted SQL, so the blocklist doesn't
break them.
- Add `_bq_guardrail_inputs` helper: walks user SQL twice — once for
bare-name matches against accessible registered remote-BQ names
(contributes to dry_run_set), once for direct `bq.X.Y` matches
(gated against `find_by_bq_path` lookups, returns 403 with
structured detail on miss or grant violation).
- Add `_enforce_remote_bq_quota_and_cap` helper: pre-flight
`check_daily_budget` (over-cap → 429), then `with quota.acquire(...)`
wraps a per-path BQ dry-run, sums bytes, raises 400
`remote_scan_too_large` when total > cap.
- Cap default 5 GiB; configurable via `api.query.bq_max_scan_bytes`
in /admin/server-config (next phase wires the UI).
- Post-flight `record_bytes` against the user's daily counter.
- Module-level imports of `_bq_dry_run_bytes`, `_build_quota_tracker`,
`get_bq_access` so tests can monkeypatch via `app.api.query.<name>`.
Tests:
- All 23 RED tests from the previous commit now pass (regex matrix,
blocklist with detail-string assertion, RBAC unregistered/admin-bypass,
guardrail dry-run-called/over-cap-rejected, quota pre-flight 429).
- mock_dry_run fixture stubs both `_bq_dry_run_bytes` and `get_bq_access`
so guardrail tests don't require a live BQ project.
- Quota test uses `admin1` (the seeded_app fixture's actual user id, not
`admin`).
Smoke: 887 passed across query/bq/admin/extractor/registry/quota
domains. No regressions.
5 new test files for the upcoming /api/query pre-flight block (next
commit). All failing for the right reason on the current codebase:
tests/test_query_bq_regex.py (8 + 1 + 7 + 1 = 17 cases)
Pure unit test of `BQ_PATH` regex constant (not yet imported from
app.api.query). Verifies the 16-case matrix from spec §4.3.1:
positive matches for fully-quoted / unquoted / mixed quoting / case
variants / inside CTE bodies / multiple paths in one statement;
negative for bare registered names / 2-part bq.col / prefix that
contains bq / middle-component bq / quoted bare names; documented
string-literal false-positive accepted.
tests/test_query_bigquery_query_blocked.py (3 cases)
POST /api/query with bigquery_query() function call must hit the
canonical blocklist rejection ("Only single SELECT queries are
allowed"). Today the blocklist passes all 3 — confirmed RED via
detail-string assertion.
tests/test_api_query_rbac_bq_path.py (4 cases)
Direct bq."<ds>"."<tbl>" references must be registry-gated:
unregistered → 403 bq_path_not_registered; registered + admin →
bypass per-name grant; case-insensitive lookup; string-literal
containing bq.X.Y → 403 (strict-deny).
tests/test_api_query_guardrail.py (3 cases)
Cost guardrail: SQL referencing a registered remote BQ row invokes
_bq_dry_run_bytes (verified via call-counter side effect); over-cap
dry-run returns 400 remote_scan_too_large with bytes/tables/suggestion
in detail; non-BQ queries skip the dry-run entirely.
tests/test_api_query_quota.py (3 cases)
Daily-byte quota check_daily_budget pre-flight (over-cap → 429
before dry-run); record_bytes post-flight on the shared singleton
v2_quota tracker; non-BQ queries leave the counter alone.
RED breakdown: 16 ImportError (BQ_PATH not yet defined) + 7 assertion
failures = 23 fully-RED. 6 tests pass for regression-green reasons
(use `if r.status_code == 403:` patterns where current code returns
400 for unrelated reasons). They serve as anti-regression guards once
the implementation lands and remain green throughout — documented per
spec §6 Phase 1 RED-discipline notes.
