报错:
book-manager-app | 2026-04-26T10:06:31.294Z ERROR --- [main] o.h.engine.jdbc.spi.SqlExceptionHelper : Communications link failure book-manager-app | Caused by: java.net.UnknownHostException: mysql: Name or service not known book-manager-app exited with code 1
最后解决
启动顺序问题:虽然配置了depends_on,但 MySQL 可能还没完全就绪
# 1. 清理
docker compose down -v
# 2. 只启动 MySQL
docker compose up -d mysql
# 3. 等 MySQL 完全启动(15秒)
sleep 30
# 4. 再启动 app
docker compose up -d app
# 5. 查看日志
docker compose logs app
mysql 没准备好 等他准备好就行了