82ceafa7bc
This patch set adds use cases for each of the mutation operations used by Deckhand: * substitution * layering * replacement To help document authors decide which operations they should use. Change-Id: I8bc470c7ddc2f3c0aa9d4372a2323fa84632e369
72 lines
2.2 KiB
ReStructuredText
72 lines
2.2 KiB
ReStructuredText
..
|
|
Copyright 2018 AT&T Intellectual Property.
|
|
All Rights Reserved.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
not use this file except in compliance with the License. You may obtain
|
|
a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
License for the specific language governing permissions and limitations
|
|
under the License.
|
|
|
|
.. _rendering:
|
|
|
|
Document Rendering
|
|
==================
|
|
|
|
Document rendering involves extracting all raw revision documents from
|
|
Deckhand's database, retrieving encrypted information from `Barbican`_,
|
|
and applying substitution, layering and replacement algorithms on the
|
|
data.
|
|
|
|
The following algorithms are involved during the rendering process:
|
|
|
|
:ref:`substitution`
|
|
-------------------
|
|
|
|
Substitution provides an "open" data sharing model in which any source
|
|
document can be used to substitute data into any destination document.
|
|
|
|
Use Cases
|
|
^^^^^^^^^
|
|
|
|
* Sharing of data between specific documents no matter their ``schema``.
|
|
* Data sharing using pattern matching.
|
|
* Fine-grained sharing of specific sections of data.
|
|
|
|
:ref:`layering`
|
|
---------------
|
|
|
|
Layering provides a "restricted" data inheritance model intended to help
|
|
reduce duplication in configuration.
|
|
|
|
Use Cases
|
|
^^^^^^^^^
|
|
|
|
* Sharing of data between documents with the same ``schema``.
|
|
* Deep merging of objects and lists.
|
|
* Layer order with multiple layers, resulting in a larger hierarchy of
|
|
documents.
|
|
* Source document for data sharing can be identified via labels, allowing for
|
|
different documents to be used as the source for sharing, depending on
|
|
:ref:`parent-selection`.
|
|
|
|
:ref:`replacement`
|
|
------------------
|
|
|
|
Replacement builds on top of layering to provide yet another mechanism
|
|
for reducing data duplication.
|
|
|
|
Use Cases
|
|
^^^^^^^^^
|
|
|
|
* Same as layering, but with a need to replace higher-layer documents with
|
|
lower-layer documents for specific site deployments.
|
|
|
|
.. _Barbican: https://docs.openstack.org/barbican/latest/api/
|