Introduction
In this tutorial you will learn how to install certbot which communicates with Let's Encrypt. We will create an SSL certificate for our example.com domain and adapt the Nginx configuration as well as the ufw configuration.
Prerequisites
- Setup Ubuntu 20.04
- Install Nginx on Ubuntu 20.04
- A top-level domain, e.g.
example.com
Step 1 - Install Certbot
First, update your server:
holu@10.0.0.1:~$ sudo apt-get update && sudo apt-get upgrade -yThen we are going to install Certbot:
holu@10.0.0.1:~$ sudo apt install certbot python3-certbot-nginxStep 2 - Allow HTTPS traffic
In the earlier tutorials we only allowed HTTP traffic through our firewall. So your ufw status should look like this:
holu@10.0.0.1:~$ sudo ufw status
Status: active
To Action From
-- ------ ----
OpenSSH ALLOW Anywhere
Nginx HTTP ALLOW Anywhere
OpenSSH (v6) ALLOW Anywhere (v6)
Nginx HTTP (v6) ALLOW Anywhere (v6)Now we need to change this to also allow HTTPS traffic:
holu@10.0.0.1:~$ sudo ufw allow 'Nginx Full'
holu@10.0.0.1:~$ sudo ufw delete allow 'Nginx HTTP'Our new ufw status looks like this:
holu@10.0.0.1:~$ sudo ufw status
Status: active
To Action From
-- ------ ----
OpenSSH ALLOW Anywhere
Nginx Full ALLOW Anywhere
OpenSSH (v6) ALLOW Anywhere (v6)
Nginx Full (v6) ALLOW Anywhere (v6)Step 3 - Get an SSL Certificate
In this step we will ask certbot to give us an SSL certificate. Certbot will also automatically adapt our Nginx configuration we previously set.
For this we need to run the following command:
holu@10.0.0.1:~$ sudo certbot --nginx -d example.comIf you will use both
example.comandwww.example.comyou need to tell it certbot in this step.holu@10.0.0.1:~$ sudo certbot --nginx -d example.com -d www.example.com
Step 3.1 - Certbot Prompt
Certbot will prompt you with the following:
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator nginx, Installer nginx
Enter email address (used for urgent renewal and security notices) (Enter 'c' to
cancel):Specify an email that you check regularly, as Let's Encrypt will warn you by email about expiring certificates.
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-v02.api.letsencrypt.org/directory
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(A)gree/(C)ancel: A
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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 our work
encrypting the web, EFF news, campaigns, and ways to support digital freedom.
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(Y)es/(N)o:Here you need to accept the terms of service and choose whether you want to subscribe to the newsletter of EFF.
Obtaining a new certificate
Performing the following challenges:
http-01 challenge for example.com
Waiting for verification...
Cleaning up challenges
Deploying Certificate to VirtualHost /etc/nginx/sites-enabled/example.com
Please choose whether or not to redirect HTTP traffic to HTTPS, removing HTTP access.
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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.
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Select the appropriate number [1-2] then [enter] (press 'c' to cancel):For new sites you should choose 2, but choose according to your needs.
Redirecting all traffic on port 80 to ssl in /etc/nginx/sites-enabled/example.com
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Congratulations! You have successfully enabled https://example.com
You should test your configuration at:
https://www.ssllabs.com/ssltest/analyze.html?d=example.com
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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 2021-11-20. 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-leYou just obtained an SSL certificate!
Your new Nginx config should look as follows:
server {
server_name example.com;
root /var/www/example.com/html;
index index.html;
location / {
try_files $uri $uri/ =404;
}
listen [::]:443 ssl ipv6only=on; # managed by Certbot
listen 443 ssl; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem; # managed by Certbot
include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
}
server {
server_name example.com;
listen 80;
listen [::]:80;
if ($host = example.com) {
return 301 https://$host$request_uri;
} # managed by Certbot
return 404; # managed by Certbot
}Conclusion
We have installed certbot which communicates with Let's Encrypt and installed an SSL certificate. Certbot also configured Nginx correctly to use our new SSL certificate. We also adapted the ufw firewall to let both HTTP and HTTPS traffic through.