How To Secure Nginx with Let's Encrypt on Ubuntu 20.04

Updated on March 1, 2021
How To Secure Nginx with Let's Encrypt on Ubuntu 20.04
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Ubuntu 20.04


Let’s Encrypt is a Certificate Authority (CA) that provides an easy way to obtain and install free TLS/SSL certificates, thereby enabling encrypted HTTPS on web servers. It simplifies the process by providing a software client, Certbot, that attempts to automate most (if not all) of the required steps. Currently, the entire process of obtaining and installing a certificate is fully automated on both Apache and Nginx.

In this tutorial, you will use Certbot to obtain a free SSL certificate for Nginx on Ubuntu 20.04 and set up your certificate to renew automatically.

This tutorial will use a separate Nginx server configuration file instead of the default file. We recommend creating new Nginx server block files for each domain because it helps to avoid common mistakes and maintains the default files as a fallback configuration.

Let DigitalOcean worry about managing Nginx and Let’s Encrypt. DigitalOcean App Platform will let you deploy directly from GitHub in minutes. App Platform will also handle SSL certs and routing for you.


To follow this tutorial, you will need:

  • One Ubuntu 20.04 server set up by following this initial server setup for Ubuntu 20.04 tutorial, including a sudo-enabled non-root user and a firewall.

  • A registered domain name. This tutorial will use example.com throughout. You can purchase a domain name from Namecheap, get one for free with Freenom, or use the domain registrar of your choice.

  • Both of the following DNS records set up for your server. If you are using DigitalOcean, please see our DNS documentation for details on how to add them.

    • An A record with example.com pointing to your server’s public IP address.
    • An A record with www.example.com pointing to your server’s public IP address.
  • Nginx installed by following How To Install Nginx on Ubuntu 20.04. Be sure that you have a server block for your domain. This tutorial will use /etc/nginx/sites-available/example.com as an example.

Step 1 — Installing Certbot

The first step to using Let’s Encrypt to obtain an SSL certificate is to install the Certbot software on your server.

Install Certbot and it’s Nginx plugin with apt:

  1. sudo apt install certbot python3-certbot-nginx

Certbot is now ready to use, but in order for it to automatically configure SSL for Nginx, we need to verify some of Nginx’s configuration.

Step 2 — Confirming Nginx’s Configuration

Certbot needs to be able to find the correct server block in your Nginx configuration for it to be able to automatically configure SSL. Specifically, it does this by looking for a server_name directive that matches the domain you request a certificate for.

If you followed the server block set up step in the Nginx installation tutorial, you should have a server block for your domain at /etc/nginx/sites-available/example.com with the server_name directive already set appropriately.

To check, open the configuration file for your domain using nano or your favorite text editor:

  1. sudo nano /etc/nginx/sites-available/example.com

Find the existing server_name line. It should look like this:

server_name example.com www.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:

  1. sudo nginx -t

If you get an error, reopen the server block file and check for any typos or missing characters. Once your configuration file’s syntax is correct, reload Nginx to load the new configuration:

  1. sudo systemctl reload nginx

Certbot can now find the correct server block and update it automatically.

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, Nginx registers a few profiles with ufw upon installation.

You can see the current setting by typing:

  1. sudo ufw status

It will probably look like this, meaning that only HTTP traffic is allowed to the web server:

Status: active To Action From -- ------ ---- OpenSSH ALLOW Anywhere Nginx HTTP ALLOW Anywhere OpenSSH (v6) ALLOW Anywhere (v6) Nginx HTTP (v6) ALLOW Anywhere (v6)

To additionally let in HTTPS traffic, allow the Nginx Full profile and delete the redundant Nginx HTTP profile allowance:

  1. sudo ufw allow 'Nginx Full'
  2. sudo ufw delete allow 'Nginx HTTP'

Your status should now look like this:

  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)

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 Nginx plugin will take care of reconfiguring Nginx and reloading the config whenever necessary. To use this plugin, type the following:

  1. sudo certbot --nginx -d example.com -d www.example.com

This runs certbot with the --nginx plugin, using -d to specify the domain names we’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.

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 Nginx 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:

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 2020-08-18. 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

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 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 systemd timer that will run twice a day and automatically renew any certificate that’s within thirty days of expiration.

You can query the status of the timer with systemctl:

  1. sudo systemctl status certbot.timer
● certbot.timer - Run certbot twice daily Loaded: loaded (/lib/systemd/system/certbot.timer; enabled; vendor preset: enabled) Active: active (waiting) since Mon 2020-05-04 20:04:36 UTC; 2 weeks 1 days ago Trigger: Thu 2020-05-21 05:22:32 UTC; 9h left Triggers: ● certbot.service

To test the renewal process, you can do a dry run with certbot:

  1. sudo certbot renew --dry-run

If you see no errors, you’re all set. When necessary, Certbot will renew your certificates and reload Nginx 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.


In this tutorial, you installed the Let’s Encrypt client certbot, downloaded SSL certificates for your domain, configured Nginx to use these certificates, and set up automatic certificate renewal. If you have further questions about using Certbot, the official documentation is a good place to start.

Want to easily configure a performant, secure, and stable Nginx server? Try our free open-source Nginx tool.

Learn more here

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After upgrading my droplet from 18.04 to 20.04, I didn’t know it, but auto-renew silently broke.

The tutorial showed me how to confirm it was broken:

$ sudo systemctl status certbot.timer
● certbot.timer
Loaded: masked (Reason: Unit certbot.timer is masked.)
Active: inactive (dead)
Trigger: n/a

But gave no clue what to do next.

I’d never heard of a system daemon being masked, but tried to unmask it. After unmasking I tried to run certbot, but it was not found. I tried to re-install, but it was unavailable.

Finally I learned, in https://askubuntu.com/questions/1278936/install-certbot-on-ubuntu-20-04 that the install instructions in this tutorial have been superceded for 20.04.

sudo snap install certbot --classic

got certbot re-installed.

From there, re-running certbot seems to have refreshed my certs.

Please update these instructions:

Correct the installation information.

Provide troubleshooting information so that others can figure out for themselves what to do when certbot gets deleted across a system upgrade.

For sub-domain SSL integration, remove www part from command just like below: Run: sudo certbot --nginx -d dev.example.com

I had issues because in my DNS Server config I had forgot to configure an A record pointing at www.example_domain.com. I only configured one for example_domain.com. Also, make sure you allow HTTP traffic through ufw until you set everything up.

Worked nicely.

Update 2022-11-18.

  1. Make sure to use digital ocean Nameservers
  2. Finish this article and then proceed to - https://www.digitalocean.com/community/tutorials/how-to-secure-nginx-with-let-s-encrypt-on-ubuntu-20-04

Once you have those 2 steps done, you should be able to see your website functional on your domain

Great stuff, straight forward.

This did not quite work for me, but I found a workaround.

After some steps, the certbot checks its work with a “http-01 challenge”. With ufw set to block HTTP requests as the article directs, those challenges fail and the process does not run to completion. After issuing the command “sudo ufw allow ‘Nginx Full’”, the certbot setup and the certbot.timer both behave as expected.

This means that my firewall configuration is a little more porous than the one recommended in the tutorial.

CAA record is needed in digital ocean for this to work completely It wasnt in your tutorial I suggest you guys add it.

Though it is in another article https://docs.digitalocean.com/products/networking/dns/how-to/create-caa-records/

this is great, work like a charm. thank you.

Hello, Thanks for the perfect article. I have an issue that I didn’t fix and maybe you have an idea.

I have three applications on the server, two of them are front-end applications coded by Vue. Both are OK.

**The third application is a backend app with ExpressJS. My requests to ExpressJS Backend App are so slow. The especially first request took almost a minute on browsers. Browsers wait until get a response. When I try with a postman throw a time-out error. **

I was very fast before SSL.

I saw the below error, console sometimes. ** “connect ETIMEDOUT” **

Web: https://www.anurbanite.com/ Rest: https://api.anurbanite.com/api/v1/product

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