semanage可以查看和配置selinux，但是，semanage在CentOS上是默认不安装的
直接使用yum install -y semanage来安装
$ yum install semanage
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
No package semanage available.
Error: Nothing to do如果出现No package semanage available.说明源中没有这个包，可以用yum provides semanage安装
$ yum provides semanage
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
base/7/x86_64/filelists_db | 7.1 MB 00:00:00
docker-ce-stable/x86_64/filelists_db | 20 kB 00:00:00
epel/x86_64/filelists_db | 12 MB 00:00:00
extras/7/x86_64/filelists_db | 205 kB 00:00:00
packages-microsoft-com-prod/filelists_db | 3.1 MB 00:00:00
updates/7/x86_64/filelists_db | 1.3 MB 00:00:00
policycoreutils-python-2.5-34.el7.x86_64 : SELinux policy core python utilities
Repo : base
Matched from:
Filename : /usr/sbin/semanage
如果还不能使用semanage，刚再输入
yum -y install policycoreutils-python.x86_64
