salt/doc/ref/returners/index.rst

120 lines
3.7 KiB
ReStructuredText

=========
Returners
=========
By default the return values of the commands sent to the Salt minions are
returned to the Salt master, however anything at all can be done with the results
data.
By using a Salt returner, results data can be redirected to external data-stores
for analysis and archival.
Returners pull their configuration values from the Salt minions. Returners are only
configured once, which is generally at load time.
The returner interface allows the return data to be sent to any system that
can receive data. This means that return data can be sent to a Redis server,
a MongoDB server, a MySQL server, or any system.
.. seealso:: :ref:`Full list of builtin returners <all-salt.returners>`
Using Returners
===============
All Salt commands will return the command data back to the master. Specifying
returners will ensure that the data is _also_ sent to the specified returner
interfaces.
Specifying what returners to use is done when the command is invoked:
.. code-block:: bash
salt '*' test.ping --return redis_return
This command will ensure that the redis_return returner is used.
It is also possible to specify multiple returners:
.. code-block:: bash
salt '*' test.ping --return mongo_return,redis_return,cassandra_return
In this scenario all three returners will be called and the data from the
test.ping command will be sent out to the three named returners.
Writing a Returner
==================
A returner is a Python module which contains a function called ``returner``.
The ``returner`` function must accept a single argument for the return data from
the called minion function. So if the minion function ``test.ping`` is called
the value of the argument will be ``True``.
A simple returner is implemented below:
.. code-block:: python
import redis
import json
def returner(ret):
'''
Return information to a redis server
'''
# Get a redis connection
serv = redis.Redis(
host='redis-serv.example.com',
port=6379,
db='0')
serv.sadd("%(id)s:jobs" % ret, ret['jid'])
serv.set("%(jid)s:%(id)s" % ret, json.dumps(ret['return']))
serv.sadd('jobs', ret['jid'])
serv.sadd(ret['jid'], ret['id'])
The above example of a returner set to send the data to a Redis server
serializes the data as JSON and sets it in redis.
Place custom returners in a ``_returners`` directory within the
:conf_master:`file_roots` specified by the master config file.
Custom returners are distributed when any of the following are called:
:mod:`state.highstate <salt.modules.state.highstate>`
:mod:`saltutil.sync_returners <salt.modules.saltutil.sync_returners>`
:mod:`saltutil.sync_all <salt.modules.saltutil.sync_all>`
Any custom returners which have been synced to a minion that are named the
same as one of Salt's default set of returners will take the place of the
default returner with the same name.
Note that a returner's default name is its filename (i.e. ``foo.py`` becomes
returner ``foo``), but that its name can be overridden by using a
:ref:`__virtual__ function <virtual-modules>`. A good example of this can be
found in the `redis`_ returner, which is named ``redis_return.py`` but is
loaded as simply ``redis``:
.. code-block:: python
try:
import redis
HAS_REDIS = True
except ImportError:
HAS_REDIS = False
__virtualname__ = 'redis'
def __virtual__():
if not HAS_REDIS:
return False
return __virtualname__
Full List of Returners
======================
.. toctree::
all/index
.. _`redis`: https://github.com/saltstack/salt/tree/develop/salt/returners/redis_return.py