启动salt-master服务报错ImportError: cannot import name EscapeFormatter

安装好salt-master和salt-minion之后，发现无法启动服务。

使用systemctl status salt-master命令查看，提示报错：

ImportError: cannot import name EscapeFormatter
      

Linux系统版本是：

# cat /etc/redhat-release
CentOS Linux release 7.5.1804 (Core) 
      

salt-master的版本是：

# yum info salt-master
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Installed Packages
Name        : salt-master
Arch        : noarch
Version     : 3000.9
Release     : 1.el7
Size        : 3.0 M
Repo        : installed
From repo   : salt-latest
Summary     : Management component for salt, a parallel remote execution system
URL         : http://saltstack.org/
License     : ASL 2.0
Description : The Salt master is the central server to which all minions connect.
      

解决方法：

# pip install --upgrade pip
# pip uninstall markupsafe
# pip install markupsafe
      

检验结果：

# python
Python 2.7.5 (default, Jul 13 2018, 13:06:57) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-28)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from markupsafe import EscapeFormatter
>>>