Archive for December, 2009

Using ELB to Serve Multiple Domains Over SSL on EC2 for Giggles and Unicorns

Wednesday, December 23rd, 2009

One of the complaints about EC2 is that you only have one IP address allocated per instance which makes it difficult to host, in a clean manner, multiple domains that require SSL certs.  Where you have control over IP allocation you could punch down a couple for one server and then set up your domains and SSL certs by IPs. That method is a no go so you are left with the ugly method of allocating those certs by port, something that Joe and Jane public are a little skittish about (https://superawesomefuntime.com is cool but https://superawesomefuntime.com:8443 smells phishy). Thankfully, ELB makes for a great proxy to hide the hideousness of the port-based workaround.

Essentially, as solutions go, this one is stupid easy; for each domain that you need to handle SSL for create a load balancer. Many balancers to one or a pool of instances. That’s it. Here’s a sloppy diagram…

For this example, we’ll be serving superawesomefuntime.com and unicorns-unlimited.com:


elb-create-lb superawesome --headers --listener "lb-port=443,instance-port=8443,protocol=TCP" --listener "lb-port=80,instance-port=80,protocol=http" --availability-zones us-east-1c


elb-create-lb unicorns --headers --listener "lb-port=443,instance-port=8445,protocol=TCP" --listener "lb-port=80,instance-port=80,protocol=http" --availability-zones us-east-1c

Take note of the address which are returned to you as need that for the cname portion of the game. They’ll look something like this: superawesome-123456789.us-east-1.elb.amazonaws.com and unicorns-987654321.us-east-1.elb.amazonaws.com.

The next step would be to add your instance to those load balancers:


elb-register-instances-with-lb superawesome --instances i-12ab3c45


elb-register-instances-with-lb unicorns --instances i-12ab3c45

Over on the server set up your virtual hosts in a way that hopefully is as hasty as mine…


NameVirtualHost *:8443
<VirtualHost *:8443>
ServerName superawesomefuntime.com
ServerAlias *.superawesomefuntime.com
SSLEngine On
SSLCertificateFile /etc/ssl/superawesome.crt
SSLCertificateKeyFile /etc/ssl/superawesome.key
RequestHeader set X_FORWARDED_PROTO 'https'
## Directories, Includes, Rewrites, oh my...
</VirtualHost>


<VirtualHost *:8445>
ServerName unicorns-unlimited.com
ServerAlias *.unicorns-unlimited.com
SSLEngine On
SSLCertificateFile /etc/ssl/unicorn.crt
SSLCertificateKeyFile /etc/ssl/unicorn.key
RequestHeader set X_FORWARDED_PROTO 'https'
## Directories, Includes, Rewrites, oh my...
</VirtualHost>

Then all you need to do is set up the cname for each domain to point at the load balancer address, in this example the cnames would be for *.superawesomefuntime.com = superawesome-123456789.us-east-1.elb.amazonaws.com and *.unicorns-unlimited = unicorns-987654321.us-east-1.elb.amazonaws.com.

The only loose end is configuring your healthcheck but that is a deeply personal decision best left for you and your app to work out.

I’m in your servers making the ‘nets flow.

Tuesday, December 22nd, 2009

I'm in your servers making the 'nets flow.

Just watching the sun rise while tickling servers…