#!/bin/sh
set -e

# Only the web (gunicorn) container should run migrations / collectstatic.
# The celery worker shares this image but skips DB schema mutation to avoid races.
#
# ⚠️ migrate 必须跨 pod 串行化(MySQL GET_LOCK):2026-07-07 事故——连推 3 个 commit 触发
# 3 轮 rolling 部署,多个新 pod 并发跑 migrate,数据迁移(积分 ×10 rescale)被交错重放 6 次,
# 测试库单价被乘成 ×10⁶(¥2 → 2,000,000)。锁把并发压成串行;后到者拿到锁时迁移已被
# 先到者记录,migrate 自然 no-op。锁超时 600s 拿不到 → 快速失败重启,绝不裸跑。
case "$1" in
  gunicorn)
    echo "[entrypoint] running migrations (serialized via DB advisory lock)..."
    python - <<'PYEOF'
import os

import django

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "airshelf.settings.production")
django.setup()

from django.core.management import call_command
from django.db import connection

if connection.vendor == "mysql":
    with connection.cursor() as cursor:
        cursor.execute("SELECT GET_LOCK('airshelf_migrate', 600)")
        acquired = cursor.fetchone()[0]
    if not acquired:
        raise SystemExit("[entrypoint] FATAL: migrate advisory lock timeout (another pod stuck?)")
    try:
        call_command("migrate", interactive=False)
    finally:
        with connection.cursor() as cursor:
            cursor.execute("SELECT RELEASE_LOCK('airshelf_migrate')")
else:
    call_command("migrate", interactive=False)
PYEOF
    echo "[entrypoint] collecting static..."
    python manage.py collectstatic --noinput
    ;;
esac

exec "$@"