salt/doc/topics/releases/0.16.0.rst

=========================
Salt 0.16.0 Release Notes
=========================

The 0.16.0 release is an exciting one, with new features in master redundancy,
and a new, powerful requisite.

Major Features
==============

Multi-Master
------------

This new capability allows for a minion to be actively connected to multiple
salt masters at the same time. This allows for multiple masters to send out commands
to minions and for minions to automatically reconnect to masters that have gone
down.

Prereq, the New Requisite
-------------------------

The new `prereq` requisite is very powerful! It allows for states to execute
based on a state that is expected to make changes in the future. This allows
for a change on the system to be preempted by another execution. A good example
is needing to shut down a service before modifying files associated with it,
allowing, for instance, a webserver to be shut down allowing a load balancer to
stop sending requests while server side code is updated. In this case, the
prereq will only run if changes are expected to happen in the prerequired
state, and the prerequired state will always run after the prereq state and
only if the prereq state succeeds.

Muliple Targets for pkg.removed, pkg.purged States
--------------------------------------------------

Both :mod:`pkg.removed <salt.states.pkg.removed>` and :mod:`pkg.purged
<salt.states.pkg.purged>` now support the ``pkgs`` argument, which allow for
multiple packages to be targeted in a single state. This, as in
:mod:`pkg.installed <salt.states.pkg.installed>`, helps speed up these
states by reducing the number of times that the package management tools (apt,
yum, etc.) need to be run.

Random Times in Cron States
---------------------------

The temporal parameters in :mod:`cron.present <salt.states.cron.present>`
states (minute, hour, etc.) can now be randomized by using ``random`` instead
of a specific value. For example, by using the ``random`` keyword in the
``minute`` parameter of a cron state, the same cron job can be pushed to
hundreds or thousands of hosts, and they would each use a randomly-generated
minute. This can be helpful when the cron job accesses a network resource, and
it is not desirable for all hosts to run the job concurrently.

.. code-block:: yaml

    /path/to/cron/script:
      cron.present:
        - user: root
        - minute: random
        - hour: 2

Since Salt assumes a value of ``*`` for unspecified temporal parameters, adding
a parameter to the state and setting it to ``random`` will change that value
from ``*`` to a randomized numeric value. However, if the cron entry contains a
numeric value on the minion, then using the ``random`` keyword will not modify
this field.