def host(proxy=None):
    '''
    This grain is set by the NAPALM grain module
    only when running in a proxy minion.
    When Salt is installed directly on the network device,
    thus running a regular minion, the ``host`` grain
    provides the physical hostname of the network device,
    as it would be on an ordinary minion server.
    When running in a proxy minion, ``host`` points to the
    value configured in the pillar: :mod:`NAPALM proxy module <salt.proxy.napalm>`.

    .. note::

        The diference between ``host`` and ``hostname`` is that
        ``host`` provides the physical location - either domain name or IP address,
        while ``hostname`` provides the hostname as configured on the device.
        They are not necessarily the same.

    .. versionadded:: 2017.7.0

    CLI Example:

    .. code-block:: bash

        salt 'device*' grains.get host

    Output:

    .. code-block:: yaml

        device1:
            ip-172-31-13-136.us-east-2.compute.internal
        device2:
            ip-172-31-11-193.us-east-2.compute.internal
        device3:
            ip-172-31-2-181.us-east-2.compute.internal
    '''
    if proxy and salt.utils.napalm.is_proxy(__opts__):
        # this grain is set only when running in a proxy minion
        # otherwise will use the default Salt grains
        return {'host': _get_device_grain('hostname', proxy=proxy)}
This grain is set by the NAPALM grain module
    only when running in a proxy minion.
    When Salt is installed directly on the network device,
    thus running a regular minion, the ``host`` grain
    provides the physical hostname of the network device,
    as it would be on an ordinary minion server.
    When running in a proxy minion, ``host`` points to the
    value configured in the pillar: :mod:`NAPALM proxy module <salt.proxy.napalm>`.

    .. note::

        The diference between ``host`` and ``hostname`` is that
        ``host`` provides the physical location - either domain name or IP address,
        while ``hostname`` provides the hostname as configured on the device.
        They are not necessarily the same.

    .. versionadded:: 2017.7.0

    CLI Example:

    .. code-block:: bash

        salt 'device*' grains.get host

    Output:

    .. code-block:: yaml

        device1:
            ip-172-31-13-136.us-east-2.compute.internal
        device2:
            ip-172-31-11-193.us-east-2.compute.internal
        device3:
            ip-172-31-2-181.us-east-2.compute.internal