Nginx with let'sencrypt

Tested on Ubuntu 20.04, and these are the appropriate commands on that platform:

apt-get update
sudo apt-get install certbot
apt-get install python-certbot-nginx

With Ubuntu 18.04 and later, substitute the Python 3 version:

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

certbot can automatically configure NGINX for SSL/TLS. It looks for and modifies
the server block in your NGINX configuration that contains a server_name directive with the
domain name you’re requesting a certificate for. In our example, the domain is www.example.com.

1. Assuming you’re starting with a fresh NGINX install, use a text editor to create a file in the /etc/nginx/conf.d directory named domain‑name.conf (so in our example, www.example.com.conf).
2. Specify your domain name (and variants, if any) with the server_name directive:

server {
    listen 80 default_server;
    listen [::]:80 default_server;
    root /var/www/html;
    server_name example.com www.example.com;
}

3. Save the file, then run this command to verify the syntax of your configuration and restart NGINX:

nginx -t && nginx -s reload

Obtain the SSL/TLS Certificate

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

1. Respond to prompts from certbot to configure your HTTPS settings, which involves entering your email address and agreeing to the Let’s Encrypt terms of service.

When certificate generation completes, NGINX reloads with the new settings. certbot generates a message indicating that certificate generation was successful and specifying the location of the certificate on your server.

Congratulations! You have successfully enabled https://example.com and https://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 2017-12-12.

If you look at domain‑name.conf, you see that certbot has modified it:

server {
    listen 80 default_server;
    listen [::]:80 default_server;
    root /var/www/html;
    server_name  example.com www.example.com;

    listen 443 ssl; # managed by Certbot

    # RSA certificate
    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

    # Redirect non-https traffic to https
    if ($scheme != "https") {
        return 301 https://$host$request_uri;
    } # managed by Certbot
}

Automatically Renew Let’s Encrypt Certificates 1. Open the crontab file

$crontab -e

2. Add the certbot command to run daily. In this example, we run the command every day at noon. The command checks to see if the certificate on the server will expire within the next 30 days, and renews it if so. The -quiet directive tells certbot not to generate output.

2. Add the `certbot` command to run daily. In this example, we run the command every day at noon. The command checks to see if the certificate on the server will expire within the next 30 days, and renews it if so. The `-quiet` directive tells `certbot` not to generate output.
    
    ```
    0 12 * * * /usr/bin/certbot renew --quiet
    ```

3. Save and close the file. All installed certificates will be automatically renewed and reloaded.