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.
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.
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