Glossary

Glossary

API server
HTTP REST API service for heat.
CFN
An abbreviated form of “AWS CloudFormation”.
Constraint
Defines valid input parameters for a template.
Dependency
When a resource must wait for another resource to finish creation before being created itself. Heat adds an implicit dependency when a resource references another resource or one of its attributes. An explicit dependency can also be created by the user in the template definition.
Environment
Used to affect the run-time behavior of the template. Provides a way to override the default resource implementation and parameters passed to Heat. See Environments.
Heat Orchestration Template
A particular template format that is native to Heat. Heat Orchestration Templates are expressed in YAML and are not backwards-compatible with CloudFormation templates.
HOT
An acronym for “Heat Orchestration Template”.
Input parameters
See Parameters.
Metadata
May refer to Resource Metadata, Nova Instance metadata, or the Metadata service.
Metadata service
A Compute service that enables virtual machine instances to retrieve instance-specific data. See Metadata service (OpenStack Administrator Guide).
Multi-region
A feature of Heat that supports deployment to multiple regions.
Nested resource
A resource instantiated as part of a nested stack.
Nested stack
A template referenced by URL inside of another template. Used to reduce redundant resource definitions and group complex architectures into logical groups.
Nova Instance metadata
User-provided key:value pairs associated with a Compute Instance. See Instance specific data (OpenStack Operations Guide).
OpenStack
Open source software for building private and public clouds.
Orchestrate
Arrange or direct the elements of a situation to produce a desired effect.
Outputs
A top-level block in a template that defines what data will be returned by a stack after instantiation.
Parameters
A top-level block in a template that defines what data can be passed to customise a template when it is used to create or update a stack.
Provider resource
A resource implemented by a provider template. The parent resource’s properties become the nested stack’s parameters. See What are “Providers”? (OpenStack Wiki).
Provider template
Allows user-definable resource providers to be specified via nested stacks. The nested stack’s outputs become the parent stack’s attributes.
Resource
An element of OpenStack infrastructure instantiated from a particular resource provider. See also Nested resource.
Resource attribute
Data that can be obtained from a resource, e.g. a server’s public IP or name. Usually passed to another resource’s properties or added to the stack’s outputs.
Resource group
A resource provider that creates one or more identically configured resources or nested resources.
Resource Metadata
A resource property that contains CFN-style template metadata. See AWS::CloudFormation::Init (AWS CloudFormation User Guide)
Resource plugin
Python code that understands how to instantiate and manage a resource. See Heat Resource Plugins (OpenStack wiki).
Resource property
Data utilized for the instantiation of a resource. Can be defined statically in a template or passed in as input parameters.
Resource provider
The implementation of a particular resource type. May be a Resource plugin or a Provider template.
Stack
A collection of instantiated resources that are defined in a single template.
Stack resource
A resource provider that allows the management of a nested stack as a resource in a parent stack.
Template
An orchestration document that details everything needed to carry out an orchestration.
Template resource
See Provider resource.
User data
A resource property that contains a user-provided data blob. User data gets passed to cloud-init to automatically configure instances at boot time. See also User data (OpenStack End User Guide).
Wait condition
A resource provider that provides a way to communicate data or events from servers back to the orchestration engine. Most commonly used to pause the creation of the stack while the server is being configured.
Creative Commons Attribution 3.0 License

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.