How to enable Apache SSL module in Ubuntu

To enable the Apache SSL module in Ubuntu, follow these steps

Update apt package cache

apt update

Install Apache SSL module

apt install libapache2-mod-ssl

Enable the SSL module

a2enmod ssl

Example

# a2enmod ssl
Considering dependency setenvif for ssl:
Module setenvif already enabled
Considering dependency mime for ssl:
Module mime already enabled
Considering dependency socache_shmcb for ssl:
Enabling module socache_shmcb.
Enabling module ssl.
See /usr/share/doc/apache2/README.Debian.gz on how to configure SSL and create self-signed certificates.
To activate the new configuration, you need to run:
  service apache2 restart
# 

Restart Apache webserver

# service apache2 restart
 * Restarting web server apache2     [ OK ] 
#

Verify Apache SSL module is installed.

# apache2ctl -M | grep ssl
 ssl_module (shared)
# 

See Configure SSL in Apache