Security Groups are used for controlling Network access, equivalent to a firewall on each instance but with coordination to make it work like a VLAN.
A general practice at Netflix is to have a security group for each application. This make it easy to grant precise connectivity between applications. In this tutorial, we're going to be creating our per-application security groups in Asgard. In this step we're creating a security group just for our ELBs, so that they can be accesssed outside of AWS.
- View Security Groups page. Which can also be accessed from the Services | EC2 | Security Groups.
- Click "Create Security Group".
- Set "Security group name" to “elb-http-public”.
- Set "Description" to “Public HTTP for ELBs”.
- Leave VPC alone
- Click "Add Rule". Select "HTTP" under the Type column. Ensure "Source" shows Anywhere.
- Click "Create".
