Steps to Add Multiple SSL Certificates on Single AWS ELB
Before we started how to add multiple SSL certificates on single AWS Elastic Load Balancer (ELB), let’s take a preview of the basics of SSL Certificates and SSL installation steps.
Multiple AWS SSL Certifications on Elastic Load Balancer (ELB)
AWS support multiple TLS/SSL certificates on Application Load Balancers (ALB) using Server Name Indication (SNI). We can now host multiple TLS secure applications, each with its own TLS certificate, behind a single load balancer. In order to use SNI, all we need to do is bind multiple certificates to the same secure listener on the load balancer. ALB will automatically choose the best TLS certificate for each client. Let us take an example for better clarity. You have two domain names. 1. Example1.com 2. Example2.com and you have hosted these two applications on the server. You can create the two separate SSL certificates for these two applications. You just have to add these certificates on listener and listener should point to the server which hosts the applications.
Procedure to create let’s encrypt the SSL certificate
1. Download and make certbot executable
wget https://dl.eff.org/certbot-auto chmod a+x certbot-auto
2. Request a new certificate
sudo ./certbot-auto --debug certonly --webroot -w /var/www/html/mydirectory -d mydomain.com
*change the webroot path /var/www/html/mydirecory/ with the webroot of your virtual host and mydomain.com with your domain name.*
3. If everything works as expected, you should now have 4 files in the /etc/letsencrypt/live/mydomain.com folder.