DEV Community

Grigor Khachatryan
Grigor Khachatryan

Posted on

How to setup Let's Encrypt for Nginx (IPv6/A+ SLL rating)

#ssl #ipv6 #nginx #letsencrypt

How to setup Let's Encrypt for Nginx on Ubuntu 18.04 (including IPv6, HTTP/2 and A+ SLL rating)

There are two modes when you don't want Certbot to edit your configuration:

  • Standalone: replaces the webserver to respond to ACME challenges
  • Webroot: needs your webserver to serve challenges from a known folder.

Webroot is better because it doesn't need to replace Nginx (to bind to port 80) to renew certificates.

In the following, we're setting up mydomain.com to be served from /var/www/mydomain, and challenges will be served from /var/www/letsencrypt.

Nginx snippets

First we create two snippets to avoid duplicating code in every virtual host configuration.

Create a file /etc/nginx/snippets/letsencrypt.conf containing:

location ^~ /.well-known/acme-challenge/ {
    default_type "text/plain";
    root /var/www/letsencrypt;
}
Enter fullscreen mode Exit fullscreen mode

Create a file /etc/nginx/snippets/ssl.conf containing:

ssl_session_timeout 1d;
ssl_session_cache shared:SSL:50m;
ssl_session_tickets off;

ssl_protocols TLSv1.2;
ssl_ciphers EECDH+AESGCM:EECDH+AES;
ssl_ecdh_curve secp384r1;
ssl_prefer_server_ciphers on;

ssl_stapling on;
ssl_stapling_verify on;

add_header Strict-Transport-Security "max-age=15768000; includeSubdomains; preload";
add_header X-Frame-Options DENY;
add_header X-Content-Type-Options nosniff;
Enter fullscreen mode Exit fullscreen mode

Nginx virtual hosts (HTTP-only)

We don't have a certificate yet at this point, so the domain is served only as HTTP.

Create a file /etc/nginx/sites-available/mydomain.conf containing:

server {
    listen 80;
    listen [::]:80 ipv6only=on;
    server_name mydomain.com www.mydomain.com;

    include /etc/nginx/snippets/letsencrypt.conf;

    root /var/www/mydomain;
    index index.html;
    location / {
        try_files $uri $uri/ =404;
    }
}
Enter fullscreen mode Exit fullscreen mode

Enable the site:

rm /etc/nginx/sites-enabled/default
ln -s /etc/nginx/sites-available/mydomain.conf /etc/nginx/sites-enabled/mydomain.conf
Enter fullscreen mode Exit fullscreen mode

And reload Nginx:

sudo systemctl reload nginx
Enter fullscreen mode Exit fullscreen mode

Note the line include /etc/nginx/snippets/letsencrypt.conf; that makes Nginx serve challenges for both http://www.mydomain.com/.well-known/acme-challenge/ and http://mydomain.com/.well-known/acme-challenge/.

Let's Encrypt client

Install the client:

sudo apt-get install letsencrypt
Enter fullscreen mode Exit fullscreen mode

Create a folder for the challenges:

sudo mkdir -p /var/www/letsencrypt/.well-known/acme-challenge
Enter fullscreen mode Exit fullscreen mode

And finally, get a certificate (don't forget to replace with your own email address):

letsencrypt certonly --webroot -w /var/www/letsencrypt -d www.domain.com -d domain.com --email MY@EMAIL.COM --agree-tos
Enter fullscreen mode Exit fullscreen mode

It will save the files in /etc/letsencrypt/live/www.mydomain.com/.

Nginx virtual hosts (HTTPS-only)

Now that you have a certificate for the domain, switch to HTTPS by editing the file /etc/nginx/sites-available/mydomain.conf and replacing contents with:

server {
    listen 80;
    listen [::]:80 ipv6only=on;
    server_name mydomain.com www.mydomain.com;

    include /etc/nginx/snippets/letsencrypt.conf;

    location / {
        return 301 https://www.mydomain.com$request_uri;
    }
}


server {
    server_name www.mydomain.com;
    listen 443 ssl http2;
    listen [::]:443 ssl http2 ipv6only=on;

    ssl_certificate /etc/letsencrypt/live/www.mydomain.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/www.mydomain.com/privkey.pem;
    ssl_trusted_certificate /etc/letsencrypt/live/www.mydomain.com/fullchain.pem;
    include /etc/nginx/snippets/ssl.conf;

    root /var/www/mydomain.com;
    index index.html;
    location / {
        try_files $uri $uri/ =404;
    }
}


server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name mydomain.com;

    ssl_certificate /etc/letsencrypt/live/www.mydomain.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/www.mydomain.com/privkey.pem;
    ssl_trusted_certificate /etc/letsencrypt/live/www.mydomain.com/fullchain.pem;
    include /etc/nginx/snippets/ssl.conf;

    location / {
        return 301 https://www.mydomain.com$request_uri;
    }
}
Enter fullscreen mode Exit fullscreen mode

Then reload Nginx:

sudo systemctl reload nginx
Enter fullscreen mode Exit fullscreen mode

Conclusion

You should now be able to see your website at https://www.mydomain.com. Congratulations 😃

You can test now also test that your domain has A+ SLL rating:

You can renew using 

letsencrypt renew
Enter fullscreen mode Exit fullscreen mode

when called it will attempt to renew certificates expiring in less than 30 days, so you can put this command in cron to renew automatically.

If letsencrypt is useful to you, consider donating to letsencrypt or donating to the EFF.

Top comments (0)

Read next

kagermanov27 profile image

Google Search Parameters (2024 Guide)

Emirhan Akdeniz -

jaloplo profile image

SharePoint Online News: Your Guide to Staying Informed

Jaime López -

fatimaalam1234 profile image

React - Virtual DOM, Reconciliation, Fiber

FatimaAlam1234 -

caresle profile image

Creating my own homelab

Carlos Estrada -