sudo yum install epel-release &&
sudo yum install httpd mod_ssl python-certbot-apache &&
sudo systemctl start httpd &&
sudo systemctl status httpd &&
sudo firewall-cmd --add-service=http &&
sudo firewall-cmd --add-service=https &&
sudo firewall-cmd --runtime-to-permanent &&

If get this issue:

  File "/usr/lib/python2.7/site-packages/urllib3/contrib/pyopenssl.py", line 147, in _validate_dependencies_met
    raise ImportError("'pyOpenSSL' module missing required functionality. "
ImportError: 'pyOpenSSL' module missing required functionality. Try upgrading to v0.14 or newer.

Install newer version of PyOpenSSL using this steps:

rpm --query centos-release  # centos-release-7-3.1611.el7.centos.x86_64
wget -c http://cbs.centos.org/kojifiles/packages/pyOpenSSL/16.2.0/3.el7/noarch/python2-pyOpenSSL-16.2.0-3.el7.noarch.rpm
sudo rpm -Uvh pyOpenSSL-0.15.1-1.el7.noarch.rpm
sudo yum install certbot

• https://github.com/certbot/certbot/issues/4514
• https://www.digitalocean.com/community/tutorials/how-to-secure-apache-with-let-s-encrypt-on-centos-7