teleo-infrastructure/ops/run_local_canonical_postgres_rebuild.py
2026-07-13 10:50:11 +02:00

819 lines
29 KiB
Python
Executable file

#!/usr/bin/env python3
"""Restore and verify a canonical PostgreSQL dump in an isolated Docker canary."""
from __future__ import annotations
import argparse
import hashlib
import json
import os
import re
import signal
import subprocess
import tempfile
import time
import uuid
from datetime import UTC, datetime
from pathlib import Path
from typing import Any
try:
from .verify_postgres_parity_manifest import compare_manifests, load_manifest
except ImportError: # pragma: no cover - direct script execution
from verify_postgres_parity_manifest import compare_manifests, load_manifest
DEFAULT_IMAGE = "postgres:16-alpine"
DEFAULT_MANIFEST_SQL = Path(__file__).with_name("postgres_parity_manifest.sql")
DATA_DIR = "/var/lib/postgresql/data"
DUMP_DESTINATION = "/tmp/teleo-canonical.dump"
MANIFEST_DESTINATION = "/tmp/postgres-parity-manifest.sql"
CANARY_LABEL = "com.livingip.teleo.canonical-rebuild-canary"
DATABASE_NAME_RE = re.compile(r"[A-Za-z_][A-Za-z0-9_]{0,62}\Z")
CONTAINER_PREFIX_RE = re.compile(r"[A-Za-z0-9][A-Za-z0-9_.-]{0,39}\Z")
ALLOWED_APPLICATION_ROLES = frozenset({"kb_apply", "kb_review"})
ROLE_BOOLEAN_FIELDS = (
"can_login",
"superuser",
"create_db",
"create_role",
"inherit",
"replication",
"bypass_rls",
)
KEY_TABLES = (
"public.claims",
"public.sources",
"public.claim_evidence",
"public.claim_edges",
"public.reasoning_tools",
"kb_stage.kb_proposals",
)
class TerminationRequested(RuntimeError):
"""Raised after SIGINT/SIGTERM so the normal cleanup path still runs."""
def sha256_file(path: Path) -> str:
digest = hashlib.sha256()
with path.open("rb") as handle:
for chunk in iter(lambda: handle.read(1024 * 1024), b""):
digest.update(chunk)
return digest.hexdigest()
def validate_custom_dump(path: Path) -> None:
if not path.is_file():
raise ValueError(f"custom dump does not exist or is not a regular file: {path}")
if path.stat().st_size <= 5:
raise ValueError("custom dump is empty or truncated")
with path.open("rb") as handle:
signature = handle.read(5)
if signature != b"PGDMP":
raise ValueError("dump is not PostgreSQL custom format (missing PGDMP signature)")
def new_container_name(prefix: str) -> str:
timestamp = datetime.now(UTC).strftime("%Y%m%d%H%M%S")
return f"{prefix}-{timestamp}-{uuid.uuid4().hex[:12]}"
def _run(
command: list[str],
*,
timeout: float,
) -> subprocess.CompletedProcess[str]:
return subprocess.run(
command,
capture_output=True,
check=False,
text=True,
timeout=timeout,
)
def _bounded_error(completed: subprocess.CompletedProcess[str]) -> str:
message = (completed.stderr or completed.stdout or "no command output").strip()
return message[-2000:]
def _require_success(completed: subprocess.CompletedProcess[str], action: str) -> str:
if completed.returncode != 0:
raise RuntimeError(f"{action} failed (exit {completed.returncode}): {_bounded_error(completed)}")
return completed.stdout
def _absence_result(completed: subprocess.CompletedProcess[str]) -> tuple[bool | None, str | None]:
if completed.returncode == 0:
return False, None
message = (completed.stderr or completed.stdout or "").strip()
lowered = message.lower()
if "no such object" in lowered or "no such container" in lowered:
return True, None
return None, message[-2000:] or f"docker inspect exited {completed.returncode}"
def inspect_container_absence(
docker_bin: str,
container: str,
*,
timeout: float,
) -> tuple[bool | None, str | None]:
completed = _run([docker_bin, "container", "inspect", container], timeout=timeout)
return _absence_result(completed)
def inspect_container_isolation(
docker_bin: str,
container: str,
*,
expected_image: str,
expected_label: str,
timeout: float,
) -> dict[str, Any]:
completed = _run([docker_bin, "container", "inspect", container], timeout=timeout)
raw = _require_success(completed, "container isolation inspection")
try:
rows = json.loads(raw)
observed = rows[0]
host_config = observed["HostConfig"]
config = observed["Config"]
except (IndexError, KeyError, TypeError, json.JSONDecodeError) as exc:
raise RuntimeError("container isolation inspection returned invalid JSON") from exc
network_mode = host_config.get("NetworkMode")
tmpfs = host_config.get("Tmpfs") or {}
labels = config.get("Labels") or {}
image = config.get("Image")
running = bool((observed.get("State") or {}).get("Running"))
problems = []
if network_mode != "none":
problems.append(f"network_mode={network_mode!r}")
if DATA_DIR not in tmpfs:
problems.append("postgres_data_tmpfs_missing")
if labels.get(CANARY_LABEL) != expected_label:
problems.append("canary_label_mismatch")
if image != expected_image:
problems.append(f"image={image!r}")
if not running:
problems.append("container_not_running")
if problems:
raise RuntimeError("container isolation check failed: " + ", ".join(problems))
return {
"network_mode": network_mode,
"postgres_data_tmpfs": tmpfs[DATA_DIR],
"image": image,
"label": labels[CANARY_LABEL],
"running": running,
}
def _psql_command(container: str, database: str, *arguments: str, docker_bin: str) -> list[str]:
return [
docker_bin,
"exec",
container,
"psql",
"-X",
"-U",
"postgres",
"-d",
database,
"-Atq",
"-v",
"ON_ERROR_STOP=1",
*arguments,
]
def wait_for_named_database(
docker_bin: str,
container: str,
database: str,
*,
startup_timeout: float,
command_timeout: float,
poll_interval: float,
) -> int:
deadline = time.monotonic() + startup_timeout
attempts = 0
last_error = "no psql attempt completed"
while True:
attempts += 1
remaining = max(0.1, deadline - time.monotonic())
completed = _run(
_psql_command(
container,
database,
"-c",
"select current_database();",
docker_bin=docker_bin,
),
timeout=min(command_timeout, remaining),
)
if completed.returncode == 0 and completed.stdout.strip() == database:
return attempts
last_error = _bounded_error(completed)
if time.monotonic() >= deadline:
raise RuntimeError(
f"named database did not accept a psql connection within {startup_timeout:g}s: {last_error}"
)
time.sleep(min(poll_interval, max(0.0, deadline - time.monotonic())))
def _role_keyword(value: bool, enabled: str, disabled: str) -> str:
return enabled if value else disabled
def application_role_sql(source_manifest: dict[str, Any]) -> str:
items = source_manifest["singleton"]["application_roles"].get("items", [])
if not isinstance(items, list):
raise ValueError("source manifest application_roles.items must be a list")
statements = []
seen: set[str] = set()
for item in items:
if not isinstance(item, dict):
raise ValueError("source manifest application role must be an object")
name = item.get("name")
if name not in ALLOWED_APPLICATION_ROLES:
raise ValueError(f"source manifest contains non-allowlisted application role: {name!r}")
if name in seen:
raise ValueError(f"source manifest contains duplicate application role: {name}")
seen.add(name)
for field in ROLE_BOOLEAN_FIELDS:
if type(item.get(field)) is not bool:
raise ValueError(f"source manifest application role {name} has invalid {field}")
attributes = [
_role_keyword(item["can_login"], "LOGIN", "NOLOGIN"),
_role_keyword(item["superuser"], "SUPERUSER", "NOSUPERUSER"),
_role_keyword(item["create_db"], "CREATEDB", "NOCREATEDB"),
_role_keyword(item["create_role"], "CREATEROLE", "NOCREATEROLE"),
_role_keyword(item["inherit"], "INHERIT", "NOINHERIT"),
_role_keyword(item["replication"], "REPLICATION", "NOREPLICATION"),
_role_keyword(item["bypass_rls"], "BYPASSRLS", "NOBYPASSRLS"),
]
statements.append(f'CREATE ROLE "{name}" {" ".join(attributes)};')
return "\n".join(statements)
def execute_application_role_bootstrap(
docker_bin: str,
container: str,
database: str,
source_manifest: dict[str, Any],
*,
timeout: float,
) -> list[str]:
sql = application_role_sql(source_manifest)
if not sql:
return []
completed = _run(
_psql_command(container, database, "-c", sql, docker_bin=docker_bin),
timeout=timeout,
)
_require_success(completed, "application role bootstrap")
return sorted(item["name"] for item in source_manifest["singleton"]["application_roles"].get("items", []))
def query_scalar(
docker_bin: str,
container: str,
database: str,
sql: str,
*,
timeout: float,
) -> str:
completed = _run(
_psql_command(container, database, "-c", sql, docker_bin=docker_bin),
timeout=timeout,
)
return _require_success(completed, "PostgreSQL readback").strip()
def collect_key_counts(
docker_bin: str,
container: str,
database: str,
*,
timeout: float,
) -> tuple[dict[str, int], int]:
counts: dict[str, int] = {}
for table in KEY_TABLES:
exists = query_scalar(
docker_bin,
container,
database,
f"select to_regclass('{table}') is not null;",
timeout=timeout,
)
if exists != "t":
raise RuntimeError(f"required canonical table is missing after restore: {table}")
schema, name = table.split(".", 1)
raw_count = query_scalar(
docker_bin,
container,
database,
f'select count(*) from "{schema}"."{name}";',
timeout=timeout,
)
try:
counts[table] = int(raw_count)
except ValueError as exc:
raise RuntimeError(f"invalid row count for {table}: {raw_count!r}") from exc
raw_table_count = query_scalar(
docker_bin,
container,
database,
"select count(*) from pg_tables where schemaname in ('public', 'kb_stage');",
timeout=timeout,
)
try:
table_count = int(raw_table_count)
except ValueError as exc:
raise RuntimeError(f"invalid canonical schema table count: {raw_table_count!r}") from exc
return counts, table_count
def run_parity_check(
docker_bin: str,
container: str,
database: str,
*,
source_manifest_path: Path,
source_manifest: dict[str, Any],
manifest_sql: Path,
command_timeout: float,
max_target_query_ms: float,
max_target_source_ratio: float,
) -> dict[str, Any]:
copy_result = _run(
[docker_bin, "cp", str(manifest_sql), f"{container}:{MANIFEST_DESTINATION}"],
timeout=command_timeout,
)
_require_success(copy_result, "parity manifest copy")
completed = _run(
_psql_command(
container,
database,
"-f",
MANIFEST_DESTINATION,
docker_bin=docker_bin,
),
timeout=command_timeout,
)
target_payload = _require_success(completed, "target parity manifest capture")
with tempfile.TemporaryDirectory(prefix="teleo-canonical-parity-") as temp_dir:
target_path = Path(temp_dir) / "target-manifest.jsonl"
target_path.write_text(target_payload, encoding="utf-8")
target_manifest = load_manifest(target_path)
problems, details = compare_manifests(
source_manifest,
target_manifest,
max_target_query_ms=max_target_query_ms,
max_target_source_ratio=max_target_source_ratio,
)
target_receipt = {
"bytes": target_path.stat().st_size,
"sha256": sha256_file(target_path),
"line_count": sum(1 for line in target_payload.splitlines() if line.strip()),
}
return {
"requested": True,
"status": "pass" if not problems else "fail",
"verifier": "ops.verify_postgres_parity_manifest.compare_manifests",
"source_manifest": {
"path": str(source_manifest_path),
"bytes": source_manifest_path.stat().st_size,
"sha256": sha256_file(source_manifest_path),
},
"target_manifest": target_receipt,
"problems": problems,
"details": details,
}
def cleanup_container(
docker_bin: str,
container: str,
*,
command_timeout: float,
poll_interval: float,
) -> dict[str, Any]:
cleanup: dict[str, Any] = {
"attempted": True,
"container": container,
"force_remove_attempted": True,
"container_absent": None,
"status": "unproven",
}
try:
removed = _run([docker_bin, "rm", "--force", container], timeout=command_timeout)
cleanup["force_remove_exit_code"] = removed.returncode
if removed.returncode != 0:
cleanup["force_remove_message"] = _bounded_error(removed)
except (OSError, subprocess.TimeoutExpired) as exc:
cleanup["force_remove_error"] = str(exc)
except (KeyboardInterrupt, TerminationRequested) as exc:
cleanup["interrupted"] = str(exc)
cleanup["force_remove_error"] = str(exc)
last_error = None
for attempt in range(1, 6):
cleanup["absence_inspection_attempts"] = attempt
try:
absent, error = inspect_container_absence(
docker_bin,
container,
timeout=command_timeout,
)
except (OSError, subprocess.TimeoutExpired) as exc:
absent, error = None, str(exc)
except (KeyboardInterrupt, TerminationRequested) as exc:
cleanup["interrupted"] = str(exc)
absent, error = None, str(exc)
if absent is True:
cleanup["container_absent"] = True
cleanup["status"] = "pass"
cleanup.pop("absence_inspection_error", None)
return cleanup
cleanup["container_absent"] = absent
last_error = error
if error and "interrupted" not in cleanup:
cleanup["absence_inspection_error"] = error
break
if attempt < 5:
try:
time.sleep(poll_interval)
except (KeyboardInterrupt, TerminationRequested) as exc:
cleanup["interrupted"] = str(exc)
if last_error:
cleanup["absence_inspection_error"] = last_error
cleanup["status"] = "fail" if cleanup["container_absent"] is False else "unproven"
return cleanup
def _initial_receipt(args: argparse.Namespace, container: str) -> dict[str, Any]:
return {
"artifact": "local_canonical_postgres_rebuild_canary",
"generated_at_utc": datetime.now(UTC).isoformat(),
"status": "running",
"database": args.database,
"dump": {
"path": str(args.dump.resolve()),
"bytes": None,
"sha256": None,
"custom_format_signature_valid": False,
},
"container": {
"name": container,
"image": args.image,
"network_mode_required": "none",
"postgres_data_tmpfs_required": f"rw,nosuid,nodev,noexec,size={args.tmpfs_mb}m",
"preexisting_absence_proven": False,
"started": False,
"isolation": None,
},
"application_roles_bootstrapped": [],
"key_counts": {},
"canonical_schema_table_count": None,
"parity": {
"requested": args.source_manifest is not None,
"status": "pending" if args.source_manifest is not None else "not_requested",
"reason": None if args.source_manifest is not None else "--source-manifest was not supplied",
},
"timings_seconds": {},
"cleanup": {
"attempted": False,
"container": container,
"container_absent": None,
"status": "pending",
},
"safety": {
"production_database_touched": False,
"network_access_available_to_container": False,
"persistent_postgres_storage_used": False,
},
"error": None,
}
def run_canary(args: argparse.Namespace) -> dict[str, Any]:
started_at = time.monotonic()
container = new_container_name(args.container_prefix)
receipt = _initial_receipt(args, container)
phase = "validation"
source_manifest: dict[str, Any] | None = None
primary_error: dict[str, str] | None = None
try:
hash_started = time.monotonic()
validate_custom_dump(args.dump)
receipt["dump"].update(
{
"bytes": args.dump.stat().st_size,
"sha256": sha256_file(args.dump),
"custom_format_signature_valid": True,
}
)
receipt["timings_seconds"]["dump_validation_and_hash"] = round(time.monotonic() - hash_started, 6)
if args.source_manifest is not None:
phase = "source_manifest_validation"
source_manifest = load_manifest(args.source_manifest)
phase = "container_name_preflight"
absent, absence_error = inspect_container_absence(
args.docker_bin,
container,
timeout=args.command_timeout,
)
if absent is not True:
detail = absence_error or "generated container name unexpectedly already exists"
raise RuntimeError(f"could not prove generated container name is unused: {detail}")
receipt["container"]["preexisting_absence_proven"] = True
phase = "container_start"
startup_started = time.monotonic()
tmpfs_options = f"{DATA_DIR}:rw,nosuid,nodev,noexec,size={args.tmpfs_mb}m"
run_result = _run(
[
args.docker_bin,
"run",
"--detach",
"--rm",
"--network",
"none",
"--name",
container,
"--label",
f"{CANARY_LABEL}={container}",
"--tmpfs",
tmpfs_options,
"--env",
f"POSTGRES_DB={args.database}",
"--env",
"POSTGRES_HOST_AUTH_METHOD=trust",
args.image,
],
timeout=args.command_timeout,
)
container_id = _require_success(run_result, "networkless PostgreSQL container start").strip()
if not container_id:
raise RuntimeError("networkless PostgreSQL container start returned no container id")
receipt["container"]["started"] = True
receipt["container"]["id_prefix"] = container_id[:12]
receipt["container"]["isolation"] = inspect_container_isolation(
args.docker_bin,
container,
expected_image=args.image,
expected_label=container,
timeout=args.command_timeout,
)
phase = "named_database_readiness"
readiness_attempts = wait_for_named_database(
args.docker_bin,
container,
args.database,
startup_timeout=args.startup_timeout,
command_timeout=args.command_timeout,
poll_interval=args.poll_interval,
)
receipt["container"]["named_database_psql_ready"] = True
receipt["container"]["named_database_psql_attempts"] = readiness_attempts
receipt["timings_seconds"]["container_start_and_named_database_ready"] = round(
time.monotonic() - startup_started,
6,
)
if source_manifest is not None:
phase = "application_role_bootstrap"
receipt["application_roles_bootstrapped"] = execute_application_role_bootstrap(
args.docker_bin,
container,
args.database,
source_manifest,
timeout=args.command_timeout,
)
phase = "dump_copy"
copy_result = _run(
[args.docker_bin, "cp", str(args.dump.resolve()), f"{container}:{DUMP_DESTINATION}"],
timeout=args.command_timeout,
)
_require_success(copy_result, "custom dump copy")
phase = "restore"
restore_started = time.monotonic()
restore_result = _run(
[
args.docker_bin,
"exec",
container,
"pg_restore",
"-U",
"postgres",
"-d",
args.database,
"--no-owner",
"--no-privileges",
"--exit-on-error",
DUMP_DESTINATION,
],
timeout=args.restore_timeout,
)
_require_success(restore_result, "canonical PostgreSQL restore")
receipt["timings_seconds"]["pg_restore"] = round(time.monotonic() - restore_started, 6)
phase = "key_count_readback"
count_started = time.monotonic()
key_counts, table_count = collect_key_counts(
args.docker_bin,
container,
args.database,
timeout=args.command_timeout,
)
receipt["key_counts"] = key_counts
receipt["canonical_schema_table_count"] = table_count
receipt["timings_seconds"]["key_count_readback"] = round(time.monotonic() - count_started, 6)
if source_manifest is not None:
phase = "parity_manifest_and_compare"
parity_started = time.monotonic()
receipt["parity"] = run_parity_check(
args.docker_bin,
container,
args.database,
source_manifest_path=args.source_manifest,
source_manifest=source_manifest,
manifest_sql=args.manifest_sql,
command_timeout=args.manifest_timeout,
max_target_query_ms=args.max_target_query_ms,
max_target_source_ratio=args.max_target_source_ratio,
)
receipt["timings_seconds"]["manifest_capture_and_parity_compare"] = round(
time.monotonic() - parity_started,
6,
)
if receipt["parity"]["status"] != "pass":
raise RuntimeError("canonical parity verification failed")
receipt["status"] = "pass"
except (
OSError,
ValueError,
RuntimeError,
subprocess.TimeoutExpired,
json.JSONDecodeError,
KeyboardInterrupt,
TerminationRequested,
) as exc:
primary_error = {
"phase": phase,
"type": type(exc).__name__,
"message": str(exc)[-2000:],
}
receipt["status"] = "fail"
receipt["error"] = primary_error
finally:
cleanup_started = time.monotonic()
cleanup = cleanup_container(
args.docker_bin,
container,
command_timeout=args.command_timeout,
poll_interval=args.poll_interval,
)
receipt["cleanup"] = cleanup
receipt["timings_seconds"]["cleanup"] = round(time.monotonic() - cleanup_started, 6)
receipt["timings_seconds"]["total"] = round(time.monotonic() - started_at, 6)
if cleanup.get("container_absent") is not True:
receipt["status"] = "fail"
cleanup_error = {
"phase": "cleanup",
"type": "CleanupProofError",
"message": "container absence was not independently proven",
}
if primary_error is None:
receipt["error"] = cleanup_error
else:
receipt["cleanup_error"] = cleanup_error
if cleanup.get("interrupted"):
receipt["status"] = "fail"
interruption_error = {
"phase": "cleanup",
"type": "TerminationRequested",
"message": cleanup["interrupted"],
}
if primary_error is None:
receipt["error"] = interruption_error
else:
receipt["cleanup_interruption"] = interruption_error
return receipt
def write_receipt(path: Path, payload: dict[str, Any]) -> None:
path = path.expanduser()
if not path.is_absolute():
path = Path.cwd() / path
path.parent.mkdir(parents=True, exist_ok=True)
path = path.parent.resolve() / path.name
encoded = (json.dumps(payload, indent=2, sort_keys=True) + "\n").encode()
temporary = path.parent / f".{path.name}.{uuid.uuid4().hex}.tmp"
descriptor = os.open(temporary, os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0o600)
try:
with os.fdopen(descriptor, "wb") as handle:
handle.write(encoded)
handle.flush()
os.fsync(handle.fileno())
os.replace(temporary, path)
os.chmod(path, 0o600)
finally:
try:
temporary.unlink()
except FileNotFoundError:
pass
def parse_args(argv: list[str] | None = None) -> argparse.Namespace:
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument("--dump", required=True, type=Path, help="PostgreSQL custom-format pg_dump")
parser.add_argument("--database", default="teleo")
parser.add_argument("--image", default=DEFAULT_IMAGE)
parser.add_argument("--container-prefix", default="teleo-canonical-rebuild")
parser.add_argument("--tmpfs-mb", default=1024, type=int)
parser.add_argument("--source-manifest", type=Path)
parser.add_argument("--manifest-sql", default=DEFAULT_MANIFEST_SQL, type=Path)
parser.add_argument("--max-target-query-ms", default=2000.0, type=float)
parser.add_argument("--max-target-source-ratio", default=20.0, type=float)
parser.add_argument("--startup-timeout", default=60.0, type=float)
parser.add_argument("--restore-timeout", default=300.0, type=float)
parser.add_argument("--manifest-timeout", default=180.0, type=float)
parser.add_argument("--command-timeout", default=30.0, type=float)
parser.add_argument("--poll-interval", default=0.25, type=float)
parser.add_argument("--docker-bin", default="docker")
parser.add_argument("--output", required=True, type=Path)
args = parser.parse_args(argv)
if not DATABASE_NAME_RE.fullmatch(args.database):
parser.error("--database must be a safe PostgreSQL identifier up to 63 characters")
if not CONTAINER_PREFIX_RE.fullmatch(args.container_prefix):
parser.error("--container-prefix must be 1-40 Docker-safe characters")
if not args.image or any(character.isspace() for character in args.image):
parser.error("--image must be a non-empty Docker image reference without whitespace")
if not args.docker_bin or any(character.isspace() for character in args.docker_bin):
parser.error("--docker-bin must be one executable name or path without whitespace")
if not 64 <= args.tmpfs_mb <= 65536:
parser.error("--tmpfs-mb must be between 64 and 65536")
for value, flag in (
(args.startup_timeout, "--startup-timeout"),
(args.restore_timeout, "--restore-timeout"),
(args.manifest_timeout, "--manifest-timeout"),
(args.command_timeout, "--command-timeout"),
(args.poll_interval, "--poll-interval"),
(args.max_target_query_ms, "--max-target-query-ms"),
(args.max_target_source_ratio, "--max-target-source-ratio"),
):
if value <= 0:
parser.error(f"{flag} must be positive")
if not args.dump.is_file():
parser.error("--dump must be an existing regular file")
if args.source_manifest is not None:
if not args.source_manifest.is_file():
parser.error("--source-manifest must be an existing regular file")
if not args.manifest_sql.is_file():
parser.error("--manifest-sql must be an existing regular file when parity is requested")
protected_inputs = {args.dump.resolve(), args.manifest_sql.resolve()}
if args.source_manifest is not None:
protected_inputs.add(args.source_manifest.resolve())
if args.output.resolve() in protected_inputs:
parser.error("--output must not overwrite a dump or manifest input")
return args
def _termination_handler(signum: int, _frame: Any) -> None:
raise TerminationRequested(f"received {signal.Signals(signum).name}")
def main(argv: list[str] | None = None) -> int:
args = parse_args(argv)
previous_handlers = {}
for watched_signal in (signal.SIGINT, signal.SIGTERM):
previous_handlers[watched_signal] = signal.getsignal(watched_signal)
signal.signal(watched_signal, _termination_handler)
try:
payload = run_canary(args)
finally:
for watched_signal, previous in previous_handlers.items():
signal.signal(watched_signal, previous)
try:
write_receipt(args.output, payload)
except OSError as exc:
payload["status"] = "fail"
payload["receipt_write_error"] = str(exc)
print(json.dumps(payload, indent=2, sort_keys=True))
return 0 if payload["status"] == "pass" else 1
if __name__ == "__main__":
raise SystemExit(main())