The nova-api service is a component of OpenStack, an open-source cloud computing platform. OpenStack Nova provides a compute service that allows users to provision and manage virtual machines (VMs) on a cluster of physical servers. The nova-api service acts as an interface or API endpoint for users and other OpenStack services to interact with Nova.
The primary role of the nova-api service is to handle requests and provide a RESTful API for managing VMs and related resources. It receives requests from clients, such as the OpenStack dashboard (Horizon), command-line interface (CLI), or other services within the OpenStack ecosystem. These requests can include actions like creating, updating, or deleting VMs, as well as querying information about instances, flavors, images, and other Nova resources.
When a request is received by the nova-api service, it validates the request, authorizes the user, and performs the requested action or communicates with other components of the Nova service to complete the operation. It acts as a central point for coordinating and managing compute resources in an OpenStack deployment.
The nova-api service communicates with other components of OpenStack, such as the nova-compute service responsible for managing the hypervisor and physical servers, as well as the nova-scheduler for resource scheduling decisions. It also interacts with other OpenStack services like Keystone for authentication and authorization, Glance for image management, and Neutron for networking.
In summary, the nova-api service in OpenStack Nova is responsible for providing an API endpoint for users and other services to interact with the compute service, enabling the provisioning and management of virtual machines in a cloud computing environment.