找到yum.conf
[root@d78acc291c9e var]# find / -name yum.conf /etc/yum.conf
注释掉exclude那行，也可只删除httpd
[main] gpgcheck=1 installonly_limit=3 clean_requirements_on_remove=True best=True #exclude=httpd nginx php mysql mairadb python-psutil python2-psutil
//重新安装
yum install httpd -y systemctl enable httpd systemctl start httpd systemctl status httpd
Active: active (running)
Status: "Started, listening on: port 80"
[root@d78acc291c9e var]# httpd -v Server version: Apache/2.4.37 (centos) Server built: Dec 23 2019 20:45:34
参考：
https://www.linuxquestions.org/questions/fedora-35/yum-can%27t-find-httpd-or-apache-547678/