Heat (OpenStack)

Heat (OpenStack)
Name	Heat
Developer	OpenStack Foundation
Released	2012
Programming language	Python
Operating system	Linux
License	Apache License 2.0

Heat (OpenStack) Heat is the orchestration service for the OpenStack cloud computing platform, designed to automate the deployment and lifecycle management of cloud applications through template-driven resource orchestration. It provides a declarative model to provision compute, storage, networking, and higher-level services across an OpenStack cloud, integrating with multiple OpenStack projects and industry technologies. Heat is used in production by organizations that include telecommunications carriers, financial institutions, and research laboratories seeking reproducible infrastructure-as-code workflows.

Overview

Heat originated as an OpenStack project effort to provide orchestration capabilities complementary to projects such as Nova (OpenStack Compute), Neutron (OpenStack Networking), Cinder (OpenStack Block Storage), and Glance (OpenStack Image Service). It exposes APIs influenced by Amazon Web Services (AWS) CloudFormation paradigms while aligning with the governance model of the OpenStack Foundation and the development processes of OpenStack Summit contributors. Early adopters included Rackspace, NASA, and Intel, and later contributors comprised vendors such as Red Hat, Canonical (company), SUSE, and Mirantis.

Architecture

Heat implements a modular architecture integrating with multiple OpenStack services: it invokes Keystone (OpenStack Identity) for authentication and Ceilometer (OpenStack Telemetry) or Gnocchi for telemetry-driven scaling decisions. The Heat engine orchestrates via a pluggable resource registry and executes workflows using an internal translation layer and a graph-based dependency resolver. Heat interacts with infrastructure through drivers and Apache Mesos-style pluggable executors to manage lifecycle actions across Kubernetes, Docker, and LXC runtime environments when integrated. The architecture supports driver plugins developed by organizations such as Huawei, Fujitsu, Ericsson, and VMware to extend resource types and backend integrations.

Core Components

Heat consists of several core components: the Heat API, the Heat Engine, the Heat Orchestration Template (HOT) parser, resource plugins, and the Heat Translator for template transformations. The Heat API service serves REST requests and integrates with Horizon (OpenStack Dashboard) and CLI tooling used by Canonical (company) and SUSE operators. The Heat Engine performs stack actions and maintains state in a persistence backend such as MySQL or MariaDB, often deployed alongside RabbitMQ or Apache Kafka for RPC and eventing. Resource plugins encapsulate interactions with Neutron (OpenStack Networking), Cinder (OpenStack Block Storage), Swift (OpenStack Object Storage), Ironic (OpenStack Bare Metal), and Barbican (OpenStack Key Manager).

Templates and Orchestration

Heat uses the Heat Orchestration Template (HOT) language and supports translation from AWS CloudFormation templates to HOT constructs to facilitate migration from Amazon Web Services (AWS). HOT templates describe resources, parameters, outputs, and nested stacks to model complex deployments, enabling patterns used by enterprises like Bloomberg L.P., Goldman Sachs, and JPMorgan Chase to codify infrastructure. Heat templates can reference OpenStack Swift objects, launch Nova (OpenStack Compute) instances from Glance (OpenStack Image Service) images, attach Cinder (OpenStack Block Storage) volumes, and configure Neutron (OpenStack Networking) ports and routers. Orchestration workflows leverage dependency graphs similar to those in Apache Airflow DAGs, and can integrate with configuration management systems such as Ansible, Chef, Puppet, and SaltStack.

Deployment and Use Cases

Heat is deployed in private cloud environments by organizations across sectors including Verizon Communications, Deutsche Telekom, AT&T, and BT Group for NFV and VNF lifecycle management, as well as in research outputs at institutions like CERN and European Organization for Nuclear Research. Use cases include automated multi-tier application stacks for SAP SE deployments, continuous delivery pipelines for GitLab and Jenkins-driven workflows, and edge-cloud orchestration for OpenEdge and Telecom Infra Project initiatives. Operators deploy Heat in high-availability configurations on platforms such as Red Hat Enterprise Linux, Ubuntu (operating system), and SUSE Linux Enterprise Server, often integrating with Ceph for backend storage and Kolla or Kolla-Ansible for containerized OpenStack deployments.

Security and Multi-tenancy

Heat leverages Keystone (OpenStack Identity) for multi-tenant authentication, role-based access control, and scoped tokens, aligning with security practices advocated by organizations such as NIST and compliance frameworks like SOC 2 and ISO/IEC 27001. Secrets and sensitive data can be managed through integrations with Barbican (OpenStack Key Manager) or external systems such as HashiCorp Vault and secure HSM solutions from Thales and Entrust. Heat enforces resource isolation through project-scoped stacks and policies that interoperate with Neutron (OpenStack Networking) tenant networks and Ironic (OpenStack Bare Metal) allocation policies, and it supports auditing via OpenStack Telemetry and third-party SIEM products deployed by entities like Splunk and Elastic N.V..

Development and Ecosystem Integration

Heat development follows the OpenStack release cycle with contributions from a wide community including OpenStack Foundation, corporate contributors like Red Hat, IBM, Huawei, and independent developers engaged through Gerrit and Launchpad workflows. Integration points include Horizon (OpenStack Dashboard) UI plugins, SDKs such as python-openstackclient, and CI pipelines running on Zuul and Jenkins. The ecosystem includes template repositories, upstream collaborations with projects like Mistral (OpenStack Workflow), Senlin (OpenStack Clustering), and third-party tools from vendors like Mirantis and Canonical (company), while academic research from institutions like MIT, Stanford University, and University of California, Berkeley has examined Heat for reproducible infrastructure research. Developers use languages and tools such as Python (programming language), SQLAlchemy, and SQL backends when extending Heat resource plugins and writing integration tests.

Category:OpenStack