How to install free Let\’s Encrypt SSL Certificate on Ubuntu

sudo apt-get install python-certbot-apache

After that run the commands below to obtain your free Let’s Encrypt SSL/TLS certificate for the domain myexample.com

sudo certbot --apache -m admin@example.com -d myexample.com -d www.myexample.com

After running the above commands, you should get prompted to enter your email and accept the licensing terms. If everything is checked, the client should automatically install the free SSL/TLS certificate and configure the Apache site to use the certs.

Please read the Terms of Service at
https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf. You must
agree in order to register with the ACME server at
https://acme-v01.api.letsencrypt.org/directory
-------------------------------------------------------------------------------
(A)gree/(C)ancel: A

Choose Yes ( Y ) to share your email address

Would you be willing to share your email address with the Electronic Frontier
Foundation, a founding partner of the Let\'s Encrypt project and the non-profit
organization that develops Certbot? We\'d like to send you email about EFF and
our work to encrypt the web, protect its users and defend digital rights.
-------------------------------------------------------------------------------
(Y)es/(N)o: Y

This is how easy is it to obtain your free SSL/TLS certificate for your Apache2 powered website.

Please choose whether or not to redirect HTTP traffic to HTTPS, removing HTTP access.
-------------------------------------------------------------------------------
1: No redirect - Make no further changes to the webserver configuration.
2: Redirect - Make all requests redirect to secure HTTPS access. Choose this for
new sites, or if you\'re confident your site works on HTTPS. You can undo this
change by editing your web server\'s configuration.
-------------------------------------------------------------------------------
Select the appropriate number [1-2] then [enter] (press \'c\' to cancel): 2

Pick option 2 to redirect all traffic over HTTPS. This is important!

After that, the SSL client should install the cert and configure your website to redirect all traffic over HTTPS.

Congratulations! You have successfully enabled https://example.com and
https://www.example.comYou should test your configuration at:
https://www.ssllabs.com/ssltest/analyze.html?d=example.com
https://www.ssllabs.com/ssltest/analyze.html?d=www.example.com
-------------------------------------------------------------------------------IMPORTANT NOTES:
 - Congratulations! Your certificate and chain have been saved at:
   /etc/letsencrypt/live/example.com/fullchain.pem
   Your key file has been saved at:
   /etc/letsencrypt/live/example.com/privkey.pem
   Your cert will expire on 2018-02-24. To obtain a new or tweaked
   version of this certificate in the future, simply run certbot again
   with the \"certonly\" option. To non-interactively renew *all* of
   your certificates, run \"certbot renew\"
 - If you like Certbot, please consider supporting our work by:   Donating to ISRG / Let\'s Encrypt:   https://letsencrypt.org/donate
   Donating to EFF:                    https://eff.org/donate-le

The highlighted code block should be added to your Nginx configuration file automatically by Let’s Encrypt certbot. Your site is ready to be used over HTTPS.

<VirtualHost *:80>   
  ServerAdmin admin@example.com
     DocumentRoot /var/www/html/example.com/
     ServerName myexample.com
     ServerAlias www.myexample.com
     <Directory /var/www/html/example.com/>
        Options +FollowSymlinks
        AllowOverride All
        Require all granted
     </Directory>
     ErrorLog ${APACHE_LOG_DIR}/error.log
     CustomLog ${APACHE_LOG_DIR}/access.log combined
RewriteEngine on
RewriteCond %{SERVER_NAME} =myexample.com [OR]
RewriteCond %{SERVER_NAME} =www.myexample.com
RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]
</VirtualHost>

A new configuration file for the domain should also be created named /etc/apache2/sites-available/example-le-ssl.conf. That file should contain the certificate definitions defined in it.

<IfModule mod_ssl.c>
<VirtualHost *:443>
     ServerAdmin admin@example.com
     DocumentRoot /var/www/html/example.com/
     ServerName myexample.com
     ServerAlias www.myexample.com
     
      <Directory /var/www/html/example.com/>
        Options +FollowSymlinks
        AllowOverride All
        Require all granted
     </Directory>     ErrorLog ${APACHE_LOG_DIR}/error.log
     CustomLog ${APACHE_LOG_DIR}/access.log combinedSSLCertificateFile /etc/letsencrypt/live/myexample.com/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/myexample.com/privkey.pem
Include /etc/letsencrypt/options-ssl-apache.conf
</VirtualHost>
</IfModule>

After that, browse to your domain name and the site should respond over HTTPS.

Congratulations! You’ve successfully installed Let’s Encrypt free SSL/TLS certificates.

To setup a process to automatically renew the certificates, add a cron job to execute the renewal process.

sudo crontab -e

Then add the line below and save.

0 1 * * * /usr/bin/certbot renew & > /dev/null

The cron job will attempt to renew 30 days before expiration date.