heat/doc/source/glossary.rst

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==========
 Glossary
==========

.. glossary::
   :sorted:

   API server
     HTTP REST API service for heat.

   CFN
     An abbreviated form of "AWS CloudFormation".

   Constraint
     Defines valid input :term:`parameters` for a :term:`template`.

   Dependency
     When a :term:`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 :term:`attributes <resource attribute>`. 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 :ref:`Environments`.

   Heat Orchestration Template
     A particular :term:`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 ":term:`Heat Orchestration Template`".

   Input parameters
     See :term:`Parameters`.

   Metadata
     May refer to :term:`Resource Metadata`, :term:`Nova Instance
     metadata`, or the :term:`Metadata service`.

   Metadata service
     A Compute service that enables virtual machine instances to
     retrieve instance-specific data. See `Metadata
     service (OpenStack Cloud Admin Guide)`_.

     .. _Metadata service (OpenStack Cloud Admin Guide): http://docs.openstack.org/admin-guide-cloud/content/section_metadata-service.html

   Multi-region
     A feature of Heat that supports deployment to multiple regions.

   Nested resource
     A :term:`resource` instantiated as part of a :term:`nested
     stack`.

   Nested stack
     A :term:`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 Compute Admin
     Guide)`_.

     .. _Instance specific data (OpenStack Compute Admin Guide): http://docs.openstack.org/grizzly/openstack-compute/admin/content/instance-data.html#inserting_metadata

   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 :term:`template` that defines what data
     will be returned by a stack after instantiation.

   Parameters
     A top-level block in a :term:`template` that defines what data
     can be passed to customise a template when it is used to create
     or update a :term:`stack`.

   Provider resource
     A :term:`resource` implemented by a :term:`provider
     template`. The parent resource's properties become the
     :term:`nested stack's <nested stack>` parameters. See `What are
     "Providers"? (OpenStack Wiki)`_.

     .. _`What are "Providers"? (OpenStack Wiki)`: https://wiki.openstack.org/wiki/Heat/Providers#What_are_.22Providers.22.3F

   Provider template
     Allows user-definable :term:`resource providers <resource
     provider>` to be specified via :term:`nested stacks <nested
     stack>`. The nested stack's :term:`outputs` become the parent
     stack's :term:`attributes <resource attribute>`.

   Resource
     An element of OpenStack infrastructure instantiated from a
     particular :term:`resource provider`. See also :term:`Nested
     resource`.

   Resource attribute
     Data that can be obtained from a :term:`resource`, e.g. a
     server's public IP or name. Usually passed to another resource's
     :term:`properties <resource property>` or added to the stack's
     :term:`outputs`.

   Resource group
     A :term:`resource provider` that creates one or more identically
     configured :term:`resources <resource>` or :term:`nested
     resources <nested resource>`.

   Resource Metadata
     A :term:`resource property` that contains CFN-style template
     metadata. See `AWS::CloudFormation::Init (AWS CloudFormation User Guide)`_

     .. _AWS::CloudFormation::Init (AWS CloudFormation User Guide): http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-init.html

   Resource plugin
     Python code that understands how to instantiate and manage a
     :term:`resource`. See `Heat Resource Plugins (OpenStack wiki)`_.

     .. _Heat Resource Plugins (OpenStack wiki): https://wiki.openstack.org/wiki/Heat/Plugins#Heat_Resource_Plugins

   Resource property
     Data utilized for the instantiation of a :term:`resource`. Can be
     defined statically in a :term:`template` or passed in as
     :term:`input parameters <parameters>`.

   Resource provider
     The implementation of a particular resource type. May be a
     :term:`Resource plugin` or a :term:`Provider template`.

   Stack
     A collection of instantiated :term:`resources <resource>` that
     are defined in a single :term:`template`.

   Stack resource
     A :term:`resource provider` that allows the management of a
     :term:`nested stack` as a :term:`resource` in a parent stack.

   Template
     An orchestration document that details everything needed to carry
     out an :term:`orchestration <orchestrate>`.

   Template resource
     See :term:`Provider resource`.

   User data
     A :term:`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)`_.

     .. _User data (OpenStack End User Guide): http://docs.openstack.org/user-guide/content/user-data.html#d6e2415
     .. _cloud-init: https://help.ubuntu.com/community/CloudInit

   Wait condition
     A :term:`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
     :term:`stack` while the server is being configured.