Step 1 — Installing Certbot
First, add the repository:
sudo add-apt-repository ppa:certbot/certbot
You’ll need to press ENTER to accept.
Install Certbot’s Apache package with apt:
sudo apt install python-certbot-apache
Certbot is now ready to use, but in order for it to configure SSL for Apache,
we need to verify some of Apache’s configuration.
Step 2 — Set Up the SSL Certificate
Certbot needs to be able to find the correct virtual host in your
Apache configuration for it to automatically configure SSL.
Specifically, it does this by looking for a ServerName directive that
matches the domain you request a certificate for.
If you followed the virtual host set up step in the Apache installation tutorial,
you should have a VirtualHost block for your domain at
/etc/apache2/sites-available/example.com.conf
with the ServerName directive already set appropriately.
To check, open the virtual host file for your domain using nano or your favorite text editor:
sudo nano /etc/apache2/sites-available/example.com.conf
Find the existing ServerName line. It should look like this:
/etc/apache2/sites-available/example.com.conf
...
ServerName example.com;
...
If it does, exit your editor and move on to the next step.
If it doesn’t, update it to match.
Then save the file, quit your editor, and verify the syntax of your configuration edits:
sudo apache2ctl configtest
If you get an error, reopen the virtual host file and check for
any typos or missing characters.
Once your configuration file's syntax is correct,
reload Apache to load the new configuration:
sudo systemctl reload apache2
Certbot can now find the correct VirtualHost block and update it.
Next, let's update the firewall to allow HTTPS traffic.
Step 3 — Allowing HTTPS Through the Firewall
If you have the ufw firewall enabled, as recommended by the prerequisite guides, you'll need to adjust the settings to allow for HTTPS traffic. Luckily, Apache registers a few profiles with ufw upon installation.
You can see the current setting by typing:
sudo ufw status
It will probably look like this, meaning that only HTTP traffic is allowed to the web server:
Output
Status: active
To Action From
-- ------ ----
OpenSSH ALLOW Anywhere
Apache ALLOW Anywhere
OpenSSH (v6) ALLOW Anywhere (v6)
Apache (v6) ALLOW Anywhere (v6)
To additionally let in HTTPS traffic, allow the Apache Full profile and delete the redundant Apache profile allowance:
sudo ufw allow 'Apache Full'
sudo ufw delete allow 'Apache'
Your status should now look like this:
sudo ufw status
Output
Status: active
To Action From
-- ------ ----
OpenSSH ALLOW Anywhere
Apache Full ALLOW Anywhere
OpenSSH (v6) ALLOW Anywhere (v6)
Apache Full (v6) ALLOW Anywhere (v6)
Next, let's run Certbot and fetch our certificates.
Step 4 — Obtaining an SSL Certificate
Certbot provides a variety of ways to obtain SSL certificates through plugins. The Apache plugin will take care of reconfiguring Apache and reloading the config whenever necessary. To use this plugin, type the following:
sudo certbot --apache -d example.com -d www.example.com
This runs certbot with the --apache plugin, using -d to specify the names you'd like the certificate to be valid for.
If this is your first time running certbot, you will be prompted to enter an email address and agree to the terms of service. After doing so, certbot will communicate with the Let's Encrypt server, then run a challenge to verify that you control the domain you're requesting a certificate for.
If that's successful, certbot will ask how you'd like to configure your HTTPS settings:
Output
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):
Select your choice then hit ENTER. The configuration will be updated,
and Apache will reload to pick up the new settings.
certbot will wrap up with a message telling you the process was successful
and where your certificates are stored:
Output
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 2018-07-23. 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"
- Your account credentials have been saved in your Certbot
configuration directory at /etc/letsencrypt. You should make a
secure backup of this folder now. This configuration directory will
also contain certificates and private keys obtained by Certbot so
making regular backups of this folder is ideal.
- 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
Your certificates are downloaded, installed, and loaded. Try reloading your website using https:// and notice your browser's security indicator. It should indicate that the site is properly secured, usually with a green lock icon. If you test your server using the SSL Labs Server Test, it will get an A grade.
Let's finish by testing the renewal process.
Step 5 — Verifying Certbot Auto-Renewal
Let's Encrypt's certificates are only valid for ninety days. This is to encourage users to automate their certificate renewal process. The certbot package we installed takes care of this for us by adding a renew script to /etc/cron.d. This script runs twice a day and will automatically renew any certificate that's within thirty days of expiration.
To test the renewal process, you can do a dry run with certbot:
sudo certbot renew --dry-run
If you see no errors, you're all set. When necessary, Certbot will renew your certificates and reload Apache to pick up the changes. If the automated renewal process ever fails, Let’s Encrypt will send a message to the email you specified, warning you when your certificate is about to expire.
