consulate 0.1.2

A Client library for the Consul

Consulate: A Consul Client Library
==================================

Consulate is a Python client library and set of application for the Consul
service discovery and configuration system.

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Installation
------------

Consulate is available via pypi_ and can be installed with easy_install or pip:

.. code:: bash

pip install consulate

Documentation
-------------
Documentation is available at https://consulate.readthedocs.org

Command Line Utilities
----------------------
Consulate comes with two command line utilities that make working with Consul
easier from a management perspective. The ``consulate`` application provides
a cli wrapper for common tasks performed and the ``passport`` application
implements configuration file templating.

consulate
^^^^^^^^^
The consulate application provides a CLI interface for registering a service,
backing up and restoring the contents of the KV database, and actions for getting,
setting, and deleting keys from the KV database.

.. code:: bash

usage: consulate [-h] [--api-host API_HOST] [--api-port API_PORT]
[--datacenter DATACENTER]
{register,kv} ...

optional arguments:
-h, --help show this help message and exit
--api-host API_HOST The consul host to connect on
--api-port API_PORT The consul API port to connect to
--datacenter DATACENTER
The datacenter to specify for the connection

Commands:
{register,kv}
register Register a service for this node
kv Key/Value Database Utilities

Service Registration Help:

.. code:: bash

usage: consulate register [-h] [-s SERVICE_ID] [-t TAGS]
{check,no-check,ttl} ... name port

positional arguments:
name The service name
port The port the service runs on

optional arguments:
-h, --help show this help message and exit
-s SERVICE_ID, --service-id SERVICE_ID
Specify a service ID
-t TAGS, --tags TAGS Specify a comma delimited list of tags

Service Check Options:
{check,no-check,ttl}
check Define an external script-based check
no-check Do not enable service monitoring
ttl Define a duration based TTL check

KV Database Utilities Help:

.. code:: bash

usage: consulate kv [-h] {backup,restore,get,set,del} ...

optional arguments:
-h, --help show this help message and exit

Key/Value Database Utilities:
{backup,restore,get,set,del}
backup Backup to a JSON file
restore Restore from a JSON file
get Get a key from the database
set Set a key in the database
del Delete a key from the database

passport
^^^^^^^^
Passport provides a template rendering engine that writes out configuration
files based upon information available in the consul cluster.

.. code:: bash

usage: passport [-h] [-t TEMPLATE] [-d DESTINATION]

Render templates from Consul

optional arguments:
-h, --help show this help message and exit
-t TEMPLATE, --template TEMPLATE
The path to the template
-d DESTINATION, --destination DESTINATION
The path to write the rendered template to

As an example, the following template is stored in the KV database as
``templates/memcached/memcached.conf``

.. code:: python

{% set nodes = ['%s:%s' % (r['Address'], r['ServicePort']) for r in consul.catalog.service('memcached')] %}

[memcached]
servers = {{ ','.join(nodes) }}

Invoking passport will render the file with a list of all memcached nodes to
``/etc/memcached.conf``.

.. code:: bash

passport templates/memcached/memcached.conf /etc/memcached.conf

And the output would look something like:

.. code:: ini

[memcached]
servers = 172.17.0.7:11211,172.17.0.8:11211

Template rendering is done via the `Tornado Template <https://tornado.readthedocs.org/en/latest/template.html>`_ engine.

API Usage Examples
------------------
The following examples highlight the usage of Consulate and does not document
the scope of the full Consulate API.

`Using Consulate with the Consul kv database:`

.. code:: python

session = consulate.Consulate()

# Set the key named release_flag to True
session.kv.release_flag = True

# Get the value for the release_flag, if not set, raises AttributeError
try:
should_release_feature = session.kv.release_flag
except AttributeError:
should_release_feature = False

# Delete the release_flag key
del session.kv.release_flag

# Find all keys that start with "fl"
session.kv.find('fl')

# Check to see if a key called "foo" is set
if "foo" in session.kv:
print 'Already Set'

# Return all of the items in the key/value store
session.kv.items()

`Working with the Consulate.agent API:`

.. code:: python

session = consulate.Consulate()

# Get all of the service checks for the local agent
checks = session.agent.checks()

# Get all of the services registered with the local agent
services = session.agent.services()

# Add a service to the local agent
session.agent.service.register('redis',
port=6379,
tags=['master'],
check={'script': None,
'interval': None,
'ttl': '60s'})


`Fetching health information from Consul:`

.. code:: python

session = consulate.Consulate()

# Get the health of a individual node
health = session.health.node('my-node')

# Get all checks that are critical
checks = session.heath.state('critical')

For more examples, check out the Consulate documentation.

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.. |License| image:: https://pypip.in/license/consulate/badge.svg?
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