缺失libmysqlclient.so.18

一 问题描述
更新数据库后重启Django项目，返回500.查看日志文件发现报错。

your processes number limit is 516551
your memory page size is 4096 bytes
detected max file descriptor number: 1024
lock engine: pthread robust mutexes
thunder lock: disabled (you can enable it with --thunder-lock)
uwsgi socket 0 bound to UNIX address /tmp/indel.sock fd 3
Python version: 3.5.3 (default, Sep 27 2018, 17:25:39)  [GCC 6.3.0 20170516]
Python main interpreter initialized at 0x558d197a9a80
python threads support enabled
your server socket listen backlog is limited to 100 connections
your mercy for graceful operations on workers is 60 seconds
mapped 1191168 bytes (1163 KB) for 64 cores
*** Operational MODE: preforking+threaded ***
Traceback (most recent call last):
  File "....../venv/lib/python3.5/site-packages/django/db/backends/mysql/base.py", line 15, in <module>
    import MySQLdb as Database
  File "....../venv/lib/python3.5/site-packages/MySQLdb/__init__.py", line 19, in <module>
    import _mysql
ImportError: libmysqlclient.so.18: cannot open shared object file: No such file or directory

是导入MySQLdb模块时报的错。
二 解决过程
激活环境

source venv/bin/activate
Python 3.5.3 (default, Jan 19 2017, 14:11:04)
[GCC 6.3.0 20170118] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import MySQLdb
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "....../venv/lib/python3.5/site-packages/MySQLdb/__init__.py", line 19, in <module>
    import _mysql
ImportError: libmysqlclient.so.18: cannot open shared object file: No such file or directory

本机寻找

sudo find / -name libmysqlclient.so.18
sudo locate libmysqlclient.so.18

找不到...（如果找到了，软链接到ln -s 找到的libmysqlclient.so.18文件路径 /usr/lib/libmysqlclient.so.18）
在这个页面download path(es页面)找libmysqlclient.so.18的下载地址
sudo wget -O /usr/lib/libmysqlclient.so.18 http://files.directadmin.com/services/es_7.0_64/libmysqlclient.so.18
成功解决

$ python
Python 3.5.3 (default, Jan 19 2017, 14:11:04)
[GCC 6.3.0 20170118] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import MySQLdb
>>>

重启后没有问题。
三 解决方法
1，sudo wget -O /usr/lib/libmysqlclient.so.18 http://files.directadmin.com/services/es_7.0_64/libmysqlclient.so.18
2，重启项目。