OpenStack Heat is an orchestration service within the OpenStack cloud computing platform. It provides a template-based approach to deploying and managing infrastructure resources. Heat allows users to define their infrastructure requirements using declarative templates, which can be easily versioned, shared, and reused.
Here are some key aspects and features of OpenStack Heat:
- Template-based approach: Heat uses templates written in the YAML format to describe the desired infrastructure. Templates consist of various sections, including parameters, resources, and outputs. The parameters section defines input values that can be customized during deployment. The resources section defines the infrastructure resources to be created, such as virtual machines, networks, storage volumes, and security groups. The outputs section defines the values that can be obtained after the deployment, such as IP addresses or connection details.
- Orchestration engine: Heat includes an orchestration engine that interprets the templates and manages the lifecycle of the defined resources. It ensures the proper ordering and dependency resolution of resource creation, updates, and deletions. The engine communicates with the underlying OpenStack services (e.g., Nova for compute, Neutron for networking) to provision and configure the resources.
- Stack management: In Heat, a stack is an instance of a template that represents a complete set of resources. Users can create, update, and delete stacks, which trigger the corresponding actions on the underlying resources. Heat maintains the state of each stack and allows users to perform operations like suspension, resumption, and rollback.
- Reusability and composition: Heat encourages the reuse of templates and resource definitions, enabling modular and scalable infrastructure deployments. Templates can be shared and published in a catalog, allowing users to leverage existing templates created by the community. Templates can also be composed together to create more complex deployments, using constructs like nested stacks and resource groups.
- Automation and lifecycle management: Heat enables automation of infrastructure deployment and management. Templates can be used to create entire environments with multiple resources in a single operation. Heat also supports updating stacks to apply changes to existing resources, allowing for seamless updates and scaling. Additionally, Heat integrates with other OpenStack services like Ceilometer for monitoring and scaling actions based on resource usage.
- Integration with other OpenStack components: Heat integrates with various OpenStack components, such as Keystone for authentication and authorization, Glance for image management, and Cinder for block storage. It can also leverage the Heat Orchestration Template (HOT) format, which extends the capabilities of the native Heat template language.
Components of Openstack Heat :
Overall, OpenStack Heat provides a powerful and flexible mechanism for defining, orchestrating, and managing infrastructure deployments within the OpenStack ecosystem. It simplifies the process of provisioning complex environments, promotes reusability, and enables automation of infrastructure lifecycle management.