When you compare SSL/TLS, SSL stands for Secure Socket Layer while TLS stands for Transfer Layer Security. SSL/TLS is a popular cryptographic protocol that establishes a secure connection between servers and devices by encrypting data through HTTPS protocol. 

It is an authentication protocol widely implemented in web servers and browsers creating a secure layer over insecure HTTP for secure data exchange between them. For SSL/TLS we need a valid Certificate Authority (CA) and in this article, we will use Let's Encrypt CA which is free.

Certbot is an open-source software tool for integrating and managing Let's Encrypt certificates on the web to enable secure HTTPS protocol. It will automatically manage the Let’s Encrypt certificate for you. For this you will need a valid domain with your server IP address pointed on it and Nginx with pre config server block.

Here at Ibmi Media, as part of our Server Management Services, we regularly help our Customers to perform related Let's Encrypt Certificate queries.

In this context, we shall look into how to install let’s encrypt certificates in Ubuntu 20.04 using Certbot.

How to Install Certbot on Ubuntu ?

Before proceeding with this Installation procedure, ensure that the following requirements are met:

• Your domain name should be mapped to public IP.
• Web Server (nginx, apache or any other ) for ssl termination.
• Port 80 should be allowed to the public.

To install Certbot and Nginx plugin execute the following command. Before installing the Certbot make sure you update the package info:

$ sudo apt update
$ sudo apt install certbot python3-certbot-nginx

Make sure your Nginx configuration is working properly and the domain name is included on the config.

How to Obtain Let's Encrypt Certificate Using Certbot ?

We can get an SSL Certificate in different ways using a different plugin provided by Certbot. To get the certificate we will use the certbot command along with the Nginx plugin which we have installed earlier. 

i. The Nginx plugin will manage auto-configuration and reloading Nginx config when needed. 

For this, you need to execute the following command:

$ sudo certbot --nginx

After executing the above command Certbot will provide the option for choosing the domain for which it will request the certificate for the chosen domain. Here, the subdomain we will request the certificate is option 2.

ii. Now, the Certbot will perform some tasks and again it will ask if you want to redirect HTTP traffic to HTTPS. 

Choose the number of choices you prefer and press enter.

After the redirection config is configured Certbot will begin the final setup and output the following important notes and success message.

iii. Now, if you hit the URL you will get the lock icon before your URL if you click on it, it will show 'Connection is secure'.

If you want more info on the certificate click on the certificate you will get the following result that shows you CA details like issued by, issue date, expiry date, etc.

How to Renew the SSL Certificate ?

The actual time period of the certificate is three months so you have to renew your certificate after its valid period ends. The Certbot command provides you an easy certificate renewal method.

You can first check for the renewal by executing the following command:

$ sudo certbot renew --dry-run

If there is no error you are ready to go for your actual renewal.

You just need to execute the following command and the Certbot renew it:

$ sudo certbot renew

[Need urgent assistance in fixing Certbot issues ? We can help you. ]