Files
ARR-2.0-0918/tests/local_postgres.py

105 lines
5.0 KiB
Python

"""Disposable PostgreSQL for explicitly selected integration tests only.
Never accepts a DSN, host, existing data directory or production configuration.
The cluster has no TCP listener; its trust-authenticated Unix socket is contained
in a newly generated owner-only temporary directory. All artifacts are synthetic.
"""
from __future__ import annotations
import os
from pathlib import Path
import shlex
import shutil
import subprocess
import tempfile
PROJECT = Path(__file__).resolve().parents[1]
class TemporaryPostgres:
def __init__(self):
self.root = self.data = self.socket = None
self.started = False
self._temporary = None
self._saved_pg = {}
def __enter__(self):
import psycopg
self._driver = psycopg
self.initdb, self.pg_ctl = shutil.which("initdb"), shutil.which("pg_ctl")
if not self.initdb or not self.pg_ctl:
raise RuntimeError("local PostgreSQL initdb/pg_ctl binaries are required")
self._temporary = tempfile.TemporaryDirectory(prefix="arr-pg-test-", dir="/tmp")
self.root = Path(self._temporary.name)
self.data, self.socket = self.root / "cluster", self.root / "socket"
self.socket.mkdir(mode=0o700)
# Isolate this opt-in test process from libpq defaults; restore on exit.
self._saved_pg = {k: v for k, v in os.environ.items() if k.startswith("PG")}
for key in self._saved_pg:
os.environ.pop(key)
try:
self._command([self.initdb, "-D", str(self.data), "-U", "arr_fixture",
"--auth-local=trust", "--auth-host=reject", "--encoding=UTF8", "--locale=C"])
options = shlex.join(["-k", str(self.socket), "-p", "55432", "-c", "listen_addresses=",
"-c", "unix_socket_permissions=0700", "-c", "fsync=on",
"-c", "synchronous_commit=on", "-c", "full_page_writes=on"])
self._command([self.pg_ctl, "-D", str(self.data), "-l", str(self.root / "postgres.log"),
"-o", options, "-w", "-t", "20", "start"])
self.started = True
with self.connect(database="postgres", autocommit=True) as connection:
connection.execute("CREATE DATABASE booking_test TEMPLATE template0 ENCODING 'UTF8'")
return self
except BaseException:
self.__exit__(None, None, None)
raise
@staticmethod
def _command(arguments):
result = subprocess.run(arguments, capture_output=True, text=True, timeout=35)
if result.returncode:
raise RuntimeError(f"temporary PostgreSQL command failed: {result.stdout}\n{result.stderr}")
def connect(self, _dsn=None, *, database="booking_test", autocommit=False):
connection = self._driver.connect(host=str(self.socket), port=55432, dbname=database,
user="arr_fixture", connect_timeout=5, autocommit=True)
try:
directory = connection.execute("SHOW data_directory").fetchone()[0]
if Path(directory).resolve() != self.data.resolve():
raise RuntimeError("refusing non-fixture PostgreSQL instance")
if connection.execute("SHOW listen_addresses").fetchone()[0] != "":
raise RuntimeError("fixture PostgreSQL must not listen on TCP")
connection.autocommit = autocommit
return connection
except BaseException:
connection.close()
raise
def reset_database(self):
# Only this owned cluster has passed data_directory/socket checks above.
with self.connect(database="postgres", autocommit=True) as connection:
connection.execute("DROP DATABASE booking_test WITH (FORCE)")
connection.execute("CREATE DATABASE booking_test TEMPLATE template0 ENCODING 'UTF8'")
with self.connect(autocommit=True) as connection:
existing = connection.execute("SELECT nspname FROM pg_namespace WHERE nspname IN ('ingestion','finance','booking','reporting')").fetchall()
if existing:
raise RuntimeError("schema bootstrap requires an empty fixture database")
paths = sorted(p for p in (PROJECT / "database").glob("[0-9][0-9][0-9]_*.sql")
if ".down." not in p.name and 8 <= int(p.name[:3]) <= 19)
if len(paths) != 12:
raise RuntimeError("unexpected fixture migration set")
for path in paths:
connection.execute(path.read_text(), prepare=False)
def __exit__(self, *_):
try:
# A failed start can still leave a postmaster; stop it before cleanup.
if self.data and (self.data / "postmaster.pid").exists():
self._command([self.pg_ctl, "-D", str(self.data), "-m", "fast", "-w", "-t", "20", "stop"])
self.started = False
if self._temporary is not None:
self._temporary.cleanup()
finally:
os.environ.update(self._saved_pg)