Configuring HTTPS

Get the required files

You can get a SSL certificate from a trusted Certificate Authority or generate your own. For self signed certificates the browser will show a warning that the certificate is not trusted. Here's a tutorial for using Let's Encrypt to get a free SSL Certificate

The files required are

Certificate (usually with extension .crt)
Decrypted private key

Prequisites

You need to have a DNS Multitenant Setup
Your site should be accessible via a valid domain
You need root permissions on your server
You need a valid certificate generated through a trusted Certificate Authority or a Self-Signed Certificate.

To generate .crt from private authority, generally you would have to generate a CSR (Certificate Signing Request). You may skip this step if you already have a certificate (.crt) file. To generate a CSR and the corresponding key file, run the following command:

openssl req -new -newkey rsa:2048 -nodes -keyout mydomain.com.key -out mydomain.com.csr

You need to upload this CSR (.csr) file to the private certificate authority (eg. GoDaddy, ComodoSSL) to generate a valid certificate (.crt) file against it.

If you have multiple certificates (primary and intermediate), you will have to concatenate them. For example:

cat your_certificate.crt CA.crt >> certificate_bundle.crt

Also make sure that your private key is readable only by the root user:

chown root private.key
chmod 600 private.key

Move the two files to an appropriate location

mkdir /etc/nginx/conf.d/ssl
mv private.key /etc/nginx/conf.d/ssl/private.key
mv certificate_bundle.crt /etc/nginx/conf.d/ssl/certificate_bundle.crt

Setup nginx config

Set the paths to the certificate and private key for your site

bench set-ssl-certificate site1.local /etc/nginx/conf.d/ssl/certificate_bundle.crt
bench set-ssl-key site1.local /etc/nginx/conf.d/ssl/private.key

Generate nginx config

bench setup nginx

Reload nginx

sudo service nginx reload

or

systemctl reload nginx # for CentOS 7

Now that you have configured SSL, all HTTP traffic will be redirected to HTTPS