Remember that in Chapter 8, Extending OpenStack – Advanced Networking Features and Deploying Multi-tier Applications, we had promised to continue with heat. Well, at first glance, it might be difficult to find a face of commonality between the metering infrastructure Ceilometer and the cloud application orchestration heat.
Before extending the latter example, we will shine a bright spotlight on understanding how heat is architected. Essentially, heat has a few major components, as follows:
heat-api: This is a native OpenStack HTTPd RESTful API. It mainly processes API calls by sending them to the heat engine via an advanced message queuing protocol.heat-api-cfn: This is aCloudFormationAPI service that's compatible with heat. It forwards API requests to the heat engine via an advanced messaging queue protocol.Heat Engine: This is the main part of the orchestration service where templates are processed and launched.