.. _client-apis:
.. _python-api:

=================
Python client API
=================

Salt provides several entry points for interfacing with Python applications.
These entry points are often referred to as ``*Client()`` APIs. Each client
accesses different parts of Salt, either from the master or from a minion. Each
client is detailed below.

.. seealso:: There are many ways to access Salt programmatically.

    Salt can be used from CLI scripts as well as via a REST interface.

    See Salt's :ref:`outputter system <all-salt.output>` to retrieve structured
    data from Salt as JSON, or as shell-friendly text, or many other formats.

    See the :py:func:`state.event <salt.runners.state.event>` runner to utilize
    Salt's event bus from shell scripts.

    Salt's `netapi module`_ provides access to Salt externally via a REST interface.
    Review the `netapi module`_ documentation for more information.

.. _`netapi module`: http://docs.saltstack.com/en/latest/topics/netapi/index.html

Salt's ``opts`` dictionary
==========================

Some clients require access to Salt's ``opts`` dictionary. (The dictionary
representation of the :ref:`master <configuration-salt-master>` or
:ref:`minion <configuration-salt-minion>` config files.)

A common pattern for fetching the ``opts`` dictionary is to defer to
environment variables if they exist or otherwise fetch the config from the
default location.

.. autofunction:: salt.config.client_config

.. autofunction:: salt.config.minion_config

Salt's Loader Interface
=======================

Modules in the Salt ecosystem are loaded into memory using a custom loader
system. This allows modules to have conditional requirements (OS, OS version,
installed libraries, etc) and allows Salt to inject special variables
(``__salt__``, ``__opts__``, etc).

Most modules can be manually loaded. This is often useful in third-party Python
apps or when writing tests. However some modules require and expect a full,
running Salt system underneath. Notably modules that facilitate
master-to-minion communication such as the :py:mod:`~salt.modules.mine`,
:py:mod:`~salt.modules.publish`, and :py:mod:`~salt.modules.peer` execution
modules. The error ``KeyError: 'master_uri'`` is a likely indicator for this
situation. In those instances use the :py:class:`~salt.client.Caller` class
to execute those modules instead.

Each module type has a corresponding loader function.

.. autofunction:: salt.loader.minion_mods

.. autofunction:: salt.loader.raw_mod

.. autofunction:: salt.loader.states

.. autofunction:: salt.loader.grains

.. autofunction:: salt.loader.grain_funcs

Salt's Client Interfaces
========================

LocalClient
-----------

.. autoclass:: salt.client.LocalClient
    :members: cmd, run_job, cmd_async, cmd_subset, cmd_batch, cmd_iter,
        cmd_iter_no_block, get_cli_returns, get_event_iter_returns

Salt Caller
-----------

.. autoclass:: salt.client.Caller
    :members: cmd

RunnerClient
------------

.. autoclass:: salt.runner.RunnerClient
    :members: cmd, async, cmd_sync, cmd_async

WheelClient
-----------

.. autoclass:: salt.wheel.WheelClient
    :members: cmd, async, cmd_sync, cmd_async

CloudClient
-----------

.. autoclass:: salt.cloud.CloudClient
    :members:

SSHClient
---------

.. autoclass:: salt.client.ssh.client.SSHClient
    :members: cmd, cmd_iter
