Deckhand

Deckhand is a storage service for YAML-based configuration documents, which are managed through version control and automatically validated. Deckhand provides users with a variety of different document types that describe complex configurations using the features listed below.

Core Responsibilities

• layering - helps reduce duplication in configuration while maintaining auditability across many sites
• substitution - provides separation between secret data and other configuration data, while allowing a simple interface for clients
• revision history - improves auditability and enables services to provide functional validation of a well-defined collection of documents that are meant to operate together
• validation - allows services to implement and register different kinds of validations and report errors

Getting Started

To generate a configuration file automatically:

$ tox -e genconfig

Resulting deckhand.conf.sample file is output to :path:etc/deckhand/deckhand.conf.sample

Copy the config file to a directory discoverably by oslo.conf:

$ cp etc/deckhand/deckhand.conf.sample ~/deckhand.conf

To setup an in-memory database for testing:

[database]

#
# From oslo.db
#

# The SQLAlchemy connection string to use to connect to the database.
# (string value)
connection = sqlite:///:memory:

To run locally in a development environment:

$ sudo pip install uwsgi
$ virtualenv -p python3 /var/tmp/deckhand
$ . /var/tmp/deckhand/bin/activate
$ sudo pip install .
$ sudo python setup.py install
$ uwsgi --ini uwsgi.ini

Testing

Automated Testing

To run unit tests using sqlite, execute:

$ tox -epy27
$ tox -epy35

against a py27- or py35-backed environment, respectively. To run individual unit tests, run:

$ tox -e py27 -- deckhand.tests.unit.db.test_revisions

for example.

To run unit tests using postgresql, postgresql must be installed in your environment. Then execute:

$ tox -epy27-postgresql
$ tox -epy35-postgresql

To run functional tests:

$ tox -e functional

You can also run a subset of tests via a regex:

$ tox -e functional -- gabbi.suitemaker.test_gabbi_document-crud-success-multi-bucket

Intgration Points

Deckhand has the following integration points:

• Keystone (OpenStack Identity service) provides authentication and support for role based authorization.
• PostgreSQL is used to persist information to correlate workflows with users and history of workflow commands.

Note

Currently, other database backends are not supported.

Though, being a low-level service, has many other UCP services that integrate with it, including:

• Drydock is orchestrated by Shipyard to perform bare metal node provisioning.
• Promenade is indirectly orchestrated by Shipyard to configure and join Kubernetes nodes.
• Armada is orchestrated by Shipyard to deploy and test Kubernetes workloads.

Further Reading

Undercloud Platform (UCP).