This is what I get for thinking that the GitHub in-browser editor would be sufficient. -_-
See "NOTE on Egress rules" here http://www.terraform.io/docs/providers/aws/r/security_group.html As reported here: https://github.com/hashicorp/terraform/issues/1873
Details: * Adds an input variable to the consul terraform template module to allow a user of the module to specify a different AWS instance type to launch. * The default is still "m1.small". * The module input variable is named "instance_type".