Set up Let’s Encrypt with Nginx web server with webroot plugin

This will allow the Nginx web server to read /.well-known/acme-challenge/ from each domain. This path is used by the webroot plugin.

We’ll need to make a directory to service the challenge files from, we’ll call this /home/www/letsencrypt from now on, and we’ll need to make sure this is set up with appropriate permissions so Nginx can serve these files to the public.

In Nginx’s config, we can add the following to each server block configuration:

location ^~ /.well-known/acme-challenge/ {
    default_type "text/plain";
    root /home/www/letsencrypt;
}

Generally, adding this in /etc/nginx/global/global.conf and including this file (usually already done by a default install) in each .conf file in each of /etc/nginx/conf.d/ files is recommended.

Install certbot-auto

wget https://dl.eff.org/certbot-auto && chmod a+x certbot-auto && mv certbot-auto /usr/local/bin    

Add a certificate for a domain

certbot-auto certonly --webroot -w /home/www/letsencrypt -d domain.com

Renew all certs if near expiry

certbot-auto renew --webroot -w /home/www/letsencrypt

This can be added as a cron job.

00 2 * * * root /usr/local/bin/certbot-auto renew --webroot -w /home/www/letsencrypt 2> /dev/null

If you wish the automation to apply for a single domain only, use:

00 2 * * * root /usr/local/bin/certbot-auto renew --webroot -w /home/www/letsencrypt --cert-name NAME 2> /dev/null

Certificate names are usually the same as the domain name, however this may not always be the case. You can check your certificate names with:

certbot-auto certificates

To test configuration

certbot-auto renew --webroot -w /home/www/letsencrypt --dry-run

Configure nginx server blocks

In each domain’s server block add:

listen 443 ssl;

ssl_certificate      /etc/letsencrypt/live/domain.com/fullchain.pem;
ssl_certificate_key  /etc/letsencrypt/live/domain.com/privkey.pem;
include ssl/ssl.conf;

In ssl.conf we have:

ssl_session_timeout       5m;
ssl_protocols             TLSv1 TLSv1.1 TLSv1.2;
ssl_ciphers               "ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+3DES:DH+3DES:RSA+AESGCM:RSA+AES:RSA+3DES:!aNULL:!MD5:!DSS";
ssl_prefer_server_ciphers on;
ssl_session_cache         shared:SSL:10m;
ssl_dhparam               /etc/nginx/ssl/dhparams.pem;

The above SSL config is my personal preference, but you can adjust to your liking.