Creating a stack with Heat

Now that we have installed and configured the orchestration service for OpenStack, we need to use it, and this is the time to create a stack and see Heat in action. We will use the HOT template to define a stack. HOT is an OpenStack native template system that describes the resources, which will be managed by Heat. The following is the structure of a very basic HOT template:

The following is an example of a working HOT template:

Creating an advanced template for Heat

In this example, we will use two interconnected VMs with floating IP addresses accessible from the Internet:

To deploy this stack, we need to specify different resources in the HOT template. The following diagram describes clearly resources and their dependencies:

Let's describe the resources and their dependencies:

• The first resource we define is a private network (of type OS::Neutron::Net) to which we associate a resource of type subnet (OS::Neutron::Subnet).
• Second, we define a router (of type OS...