64 lines
2.2 KiB
Python
64 lines
2.2 KiB
Python
|
"""Report whether the database schema matches the code (STATE-WP-0083-T07).
|
||
|
|
|
||
|
|
Central ran two revisions behind the code it was serving, and `review_contracts`
|
||
|
|
did not exist there although its migration shipped inside the running image.
|
||
|
|
Nothing surfaced that: the API starts happily against a schema it was not built
|
||
|
|
for, and only fails when a request happens to touch the missing table.
|
||
|
|
|
||
|
|
A hub that cannot say which schema it is running has the same problem as a
|
||
|
|
projection that cannot name its source commit — it is asserting correctness it
|
||
|
|
cannot demonstrate.
|
||
|
|
"""
|
||
|
|
|
||
|
|
from __future__ import annotations
|
||
|
|
|
||
|
|
from functools import lru_cache
|
||
|
|
from pathlib import Path
|
||
|
|
from typing import Any
|
||
|
|
|
||
|
|
from sqlalchemy import text
|
||
|
|
from sqlalchemy.ext.asyncio import AsyncSession
|
||
|
|
|
||
|
|
_MIGRATIONS = Path(__file__).resolve().parents[2] / "migrations"
|
||
|
|
|
||
|
|
|
||
|
|
@lru_cache(maxsize=1)
|
||
|
|
def code_head_revision() -> str | None:
|
||
|
|
"""The head revision the shipped migration scripts define.
|
||
|
|
|
||
|
|
Read from the migration files rather than the database: this is what the
|
||
|
|
code expects, and it must be knowable without a working connection.
|
||
|
|
"""
|
||
|
|
try:
|
||
|
|
from alembic.config import Config
|
||
|
|
from alembic.script import ScriptDirectory
|
||
|
|
|
||
|
|
cfg = Config()
|
||
|
|
cfg.set_main_option("script_location", str(_MIGRATIONS))
|
||
|
|
heads = ScriptDirectory.from_config(cfg).get_heads()
|
||
|
|
return heads[0] if len(heads) == 1 else ",".join(sorted(heads)) or None
|
||
|
|
except Exception:
|
||
|
|
return None
|
||
|
|
|
||
|
|
|
||
|
|
async def db_revision(session: AsyncSession) -> str | None:
|
||
|
|
try:
|
||
|
|
result = await session.execute(text("select version_num from alembic_version"))
|
||
|
|
return result.scalar()
|
||
|
|
except Exception:
|
||
|
|
return None
|
||
|
|
|
||
|
|
|
||
|
|
async def schema_state(session: AsyncSession) -> dict[str, Any]:
|
||
|
|
applied = await db_revision(session)
|
||
|
|
expected = code_head_revision()
|
||
|
|
# "unknown" is deliberately not "ok": an instance that cannot determine its
|
||
|
|
# own schema state must not report agreement it has not established.
|
||
|
|
if applied is None or expected is None:
|
||
|
|
status = "unknown"
|
||
|
|
elif applied == expected:
|
||
|
|
status = "ok"
|
||
|
|
else:
|
||
|
|
status = "behind"
|
||
|
|
return {"status": status, "applied": applied, "expected": expected}
|