feat(semantic-release): implement an automated changelog

.gitignore

+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+env/
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+#  Usually these files are written by a python script from a packager
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+.hypothesis/
+.kitchen
+.kitchen.local.yml
+kitchen.local.yml
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# pyenv
+.python-version
+
+# celery beat schedule file
+celerybeat-schedule
+
+# SageMath parsed files
+*.sage.py
+
+# dotenv
+.env
+
+# virtualenv
+.venv
+venv/
+ENV/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+
+# Bundler
+Gemfile.lock
+
+# copied `.md` files used for conversion to `.rst` using `m2r`
+docs/*.md

.travis.yml

+stages:
+  - test
+  - commitlint
+  - name: release
+    if: branch = master AND type != pull_request
+
+sudo: required
+cache: bundler
+language: ruby
+
+services:
+  - docker
+
+addons:
+  apt:
+    packages:
+      - ipvsadm
+
+# Make sure the instances listed below match up with
+# the `platforms` defined in `kitchen.yml`
+env:
+  matrix:
+    - INSTANCE: default-debian-9-2019-2-py3
+    - INSTANCE: default-ubuntu-1804-2019-2-py3
+    - INSTANCE: default-centos-7-2019-2-py3
+    - INSTANCE: default-fedora-29-2019-2-py3
+    - INSTANCE: default-opensuse-leap-15-2019-2-py3
+    - INSTANCE: default-debian-9-2018-3-py2
+    - INSTANCE: default-ubuntu-1604-2018-3-py2
+    - INSTANCE: default-centos-7-2018-3-py2
+    - INSTANCE: default-fedora-29-2018-3-py2
+    # TODO: Use this when fixed instead of `opensuse-leap-42`
+    # Ref: https://github.com/netmanagers/salt-image-builder/issues/2
+    # - INSTANCE: default-opensuse-leap-15-2018-3-py2
+    - INSTANCE: default-opensuse-leap-42-2018-3-py2
+    - INSTANCE: default-debian-8-2017-7-py2
+    - INSTANCE: default-ubuntu-1604-2017-7-py2
+    - INSTANCE: default-centos-6-2017-7-py2
+    - INSTANCE: default-fedora-28-2017-7-py2
+    - INSTANCE: default-opensuse-leap-42-2017-7-py2
+
+script:
+  - sudo modprobe ip_vs
+  - bundle exec kitchen verify ${INSTANCE}
+
+jobs:
+  include:
+    # Define the commitlint stage
+    - stage: commitlint
+      language: node_js
+      node_js: lts/*
+      before_install: skip
+      script:
+        - npm install @commitlint/config-conventional -D
+        - npm install @commitlint/travis-cli -D
+        - commitlint-travis
+    # Define the release stage that runs semantic-release
+    - stage: release
+      language: node_js
+      node_js: lts/*
+      before_install: skip
+      script:
+        # Update `AUTHORS.md`
+        - export MAINTAINER_TOKEN=${GH_TOKEN}
+        - go get github.com/myii/maintainer
+        - maintainer contributor
+
+        # Install all dependencies required for `semantic-release`
+        - npm install @semantic-release/changelog@3 -D
+        - npm install @semantic-release/exec@3 -D
+        - npm install @semantic-release/git@7 -D
+      deploy:
+        provider: script
+        skip_cleanup: true
+        script:
+          # Run `semantic-release`
+          - npx semantic-release@15

FORMULA

+name: keepalived
+os: Debian, Ubuntu, Raspbian, RedHat, Fedora, CentOS, Suse, openSUSE, Gentoo, Funtoo, Arch, Manjaro, Alpine, FreeBSD, OpenBSD, Solaris, SmartOS, MacOS
+os_family: Debian, RedHat, Suse, Gentoo, Arch, Alpine, FreeBSD, OpenBSD, Solaris, MacOS
+version: 1.0
+release: 0
+minimum_version: 2016.11
+summary: Rkhunter formula
+description: Formula to use to install and configure keepalived
+top_level_dir: keepalived

Gemfile

+source 'https://rubygems.org'
+
+gem 'kitchen-docker', '>= 2.9'
+gem 'kitchen-salt',   '>= 0.6.0'
+gem 'kitchen-inspec', '>= 1.1'

LICENSE

@@ -199,4 +199,3 @@
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
-

README.rst

-=======
-keepalived
-=======
-
-Install, configure and run ``keepalived``.
-
-.. note::
-
-    See the full `Salt Formulas installation and usage instructions
-    <http://docs.saltstack.com/en/latest/topics/development/conventions/formulas.html>`_.
-
-Available states
-================
-
-.. contents::
-    :local:
-
-or the jinja template and the pillar for a salt approach.
-
-``keepalived``
------------
-
-Install, configure and run ``keepalived`` service.
-
-``keepalived.install``
--------------------
-
-Install ``keepalived`` from packages.
-
-``keepalived.config``
-------------------
-
-Configuration options for ``keepalived``.
-
-``keepalived.service``
--------------------
-
-Make sure ``keepalived`` service is running.

commitlint.config.js

+module.exports = {
+    extends: ['@commitlint/config-conventional'],
+};

docs/CONTRIBUTING.rst

+.. _contributing:
+
+How to contribute
+=================
+
+This document will eventually outline all aspects of guidance to make your contributing experience a fruitful and enjoyable one.
+What it already contains is information about *commit message formatting* and how that directly affects the numerous automated processes that are used for this repo.
+It also covers how to contribute to this *formula's documentation*.
+
+.. contents:: **Table of Contents**
+
+Overview
+--------
+
+Submitting a pull request is more than just code!
+To achieve a quality product, the *tests* and *documentation* need to be updated as well.
+An excellent pull request will include these in the changes, wherever relevant.
+
+Commit message formatting
+-------------------------
+
+Since every type of change requires making Git commits,
+we will start by covering the importance of ensuring that all of your commit
+messages are in the correct format.
+
+Automation of multiple processes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This formula uses `semantic-release <https://github.com/semantic-release/semantic-release>`_ for automating numerous processes such as bumping the version number appropriately, creating new tags/releases and updating the changelog.
+The entire process relies on the structure of commit messages to determine the version bump, which is then used for the rest of the automation.
+
+Full details are available in the upstream docs regarding the `Angular Commit Message Conventions <https://github.com/angular/angular.js/blob/master/DEVELOPERS.md#-git-commit-guidelines>`_.
+The key factor is that the first line of the commit message must follow this format:
+
+.. code-block::
+
+   type(scope): subject
+
+
+* E.g. ``docs(contributing): add commit message formatting instructions``.
+
+Besides the version bump, the changelog and release notes are formatted accordingly.
+So based on the example above:
+
+..
+
+   .. raw:: html
+
+      <h3>Documentation</h3>
+
+   * **contributing:** add commit message formatting instructions
+
+
+* The ``type`` translates into a ``Documentation`` sub-heading.
+* The ``(scope):`` will be shown in bold text without the brackets.
+* The ``subject`` follows the ``scope`` as standard text.
+
+Linting commit messages in Travis CI
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This formula uses `commitlint <https://github.com/conventional-changelog/commitlint>`_ for checking commit messages during CI testing.
+This ensures that they are in accordance with the ``semantic-release`` settings.
+
+For more details about the default settings, refer back to the ``commitlint`` `reference rules <https://conventional-changelog.github.io/commitlint/#/reference-rules>`_.
+
+Relationship between commit type and version bump
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This formula applies some customisations to the defaults, as outlined in the table below,
+based upon the `type <https://github.com/angular/angular.js/blob/master/DEVELOPERS.md#type>`_ of the commit:
+
+.. list-table::
+   :name: commit-type-vs-version-bump
+   :header-rows: 1
+   :stub-columns: 0
+   :widths: 1,2,3,1,1
+
+   * - Type
+     - Heading
+     - Description
+     - Bump (default)
+     - Bump (custom)
+   * - ``build``
+     - Build System
+     - Changes related to the build system
+     - –
+     -
+   * - ``chore``
+     - –
+     - Changes to the build process or auxiliary tools and libraries such as
+       documentation generation
+     - –
+     -
+   * - ``ci``
+     - Continuous Integration
+     - Changes to the continuous integration configuration
+     - –
+     -
+   * - ``docs``
+     - Documentation
+     - Documentation only changes
+     - –
+     - 0.0.1
+   * - ``feat``
+     - Features
+     - A new feature
+     - 0.1.0
+     -
+   * - ``fix``
+     - Bug Fixes
+     - A bug fix
+     - 0.0.1
+     -
+   * - ``perf``
+     - Performance Improvements
+     - A code change that improves performance
+     - 0.0.1
+     -
+   * - ``refactor``
+     - Code Refactoring
+     - A code change that neither fixes a bug nor adds a feature
+     - –
+     - 0.0.1
+   * - ``revert``
+     - Reverts
+     - A commit used to revert a previous commit
+     - –
+     - 0.0.1
+   * - ``style``
+     - Styles
+     - Changes that do not affect the meaning of the code (white-space,
+       formatting, missing semi-colons, etc.)
+     - –
+     - 0.0.1
+   * - ``test``
+     - Tests
+     - Adding missing or correcting existing tests
+     - –
+     - 0.0.1
+
+Use ``BREAKING CHANGE`` to trigger a ``major`` version change
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Adding ``BREAKING CHANGE`` to the footer of the extended description of the commit message will **always** trigger a ``major`` version change, no matter which type has been used.
+This will be appended to the changelog and release notes as well.
+To preserve good formatting of these notes, the following format is prescribed:
+
+* ``BREAKING CHANGE: <explanation in paragraph format>.``
+
+An example of that:
+
+.. code-block:: git
+
+   ...
+
+   BREAKING CHANGE: With the removal of all of the `.sls` files under
+   `template package`, this formula no longer supports the installation of
+   packages.

docs/README.rst

+.. _readme:
+
+keepalived-formula
+==================
+
+|img_travis| |img_sr|
+
+.. |img_travis| image:: https://travis-ci.com/saltstack-formulas/keepalived-formula.svg?branch=master
+   :alt: Travis CI Build Status
+   :scale: 100%
+   :target: https://travis-ci.com/saltstack-formulas/keepalived-formula
+.. |img_sr| image:: https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg
+   :alt: Semantic Release
+   :scale: 100%
+   :target: https://github.com/semantic-release/semantic-release
+
+Formula to set up and configure keepalived
+
+.. contents:: **Table of Contents**
+
+General notes
+-------------
+
+See the full `SaltStack Formulas installation and usage instructions
+<https://docs.saltstack.com/en/latest/topics/development/conventions/formulas.html>`_.
+
+If you are interested in writing or contributing to formulas, please pay attention to the `Writing Formula Section
+<https://docs.saltstack.com/en/latest/topics/development/conventions/formulas.html#writing-formulas>`_.
+
+If you want to use this formula, please pay attention to the ``FORMULA`` file and/or ``git tag``,
+which contains the currently released version. This formula is versioned according to `Semantic Versioning <http://semver.org/>`_.
+
+See `Formula Versioning Section <https://docs.saltstack.com/en/latest/topics/development/conventions/formulas.html#versioning>`_ for more details.
+
+Contributing to this repo
+-------------------------
+
+**Commit message formatting is significant!!**
+
+Please see :ref:`How to contribute <CONTRIBUTING>` for more details.
+
+Available states
+================
+
+.. contents::
+    :local:
+
+``keepalived``
+--------------
+Installs and configures the keepalived package.
+
+``keepalived.package``
+----------------------
+Installs the keepalived package.
+
+``keepalived.config``
+---------------------
+This state manages the file ``keepalived.conf`` under ``/etc/keepalived`` (template found in "keepalived/files"). The configuration is populated by values in "keepalived/map.jinja" based on the package's default values (and RedHat, Debian, Suse and Arch family distribution specific values), which can then be overridden by values of the same name in pillar.
+
+``keepalived.service``
+----------------------
+This state ensures that keepalived service is running.

docs/TOFS_pattern.rst

+.. _tofs_pattern:
+
+TOFS: A pattern for using SaltStack
+===================================
+
+.. list-table::
+   :name: tofs-authors
+   :header-rows: 1
+   :stub-columns: 1
+   :widths: 2,2,3,2
+
+   * -
+     - Person
+     - Contact
+     - Date
+   * - Authored by
+     - Roberto Moreda
+     - moreda@allenta.com
+     - 29/12/2014
+   * - Modified by
+     - Daniel Dehennin
+     - daniel.dehennin@baby-gnu.org
+     - 07/02/2019
+   * - Modified by
+     - Imran Iqbal
+     - https://github.com/myii
+     - 23/02/2019
+
+All that follows is a proposal based on my experience with `SaltStack <http://www.saltstack.com/>`_. The good thing of a piece of software like this is that you can "bend it" to suit your needs in many possible ways, and this is one of them. All the recommendations and thoughts are given "as it is" with no warranty of any type.
+
+.. contents:: **Table of Contents**
+
+Usage of values in pillar vs templates in ``file_roots``
+--------------------------------------------------------
+
+Among other functions, the *master* (or *salt-master*) serves files to the *minions* (or *salt-minions*). The `file_roots <http://docs.saltstack.com/en/latest/ref/file_server/file_roots.html>`_ is the list of directories used in sequence to find a file when a minion requires it: the first match is served to the minion. Those files could be `state files <http://docs.saltstack.com/en/latest/topics/tutorials/starting_states.html>`_ or configuration templates, among others.
+
+Using SaltStack is a simple and effective way to implement configuration management, but even in a `non-multitenant <http://en.wikipedia.org/wiki/Multitenancy>`_ scenario, it is not a good idea to generally access some data (e.g. the database password in our `Zabbix <http://www.zabbix.com/>`_ server configuration file or the private key of our `Nginx <http://nginx.org/en/>`_ TLS certificate).
+
+To avoid this situation we can use the `pillar mechanism <http://docs.saltstack.com/en/latest/topics/pillar/>`_, which is designed to provide controlled access to data from the minions based on some selection rules. As pillar data could be easily integrated in the `Jinja <http://docs.saltstack.com/en/latest/topics/tutorials/pillar.html>`_ templates, it is a good mechanism to store values to be used in the final rendering of state files and templates.
+
+There are a variety of approaches on the usage of pillar and templates as seen in the `saltstack-formulas <https://github.com/saltstack-formulas>`_' repositories. `Some <https://github.com/saltstack-formulas/nginx-formula/pull/18>`_ `developments <https://github.com/saltstack-formulas/php-formula/pull/14>`_ stress the initial purpose of pillar data into a storage for most of the possible variables for a determined system configuration. This, in my opinion, is shifting too much load from the original template files approach. Adding up some `non-trivial Jinja <https://github.com/spsoit/nginx-formula/blob/81de880fe0276dd9488ffa15bc78944c0fc2b919/nginx/ng/files/nginx.conf>`_ code as essential part of composing the state file definitely makes SaltStack state files (hence formulas) more difficult to read. The extreme of this approach is that we could end up with a new render mechanism, implemented in Jinja, storing everything needed in pillar data to compose configurations. Additionally, we are establishing a strong dependency with the Jinja renderer.
+
+In opposition to the *put the code in file_roots and the data in pillars* approach, there is the *pillar as a store for a set of key-values* approach. A full-blown configuration file abstracted in pillar and jinja is complicated to develop, understand and maintain. I think a better and simpler approach is to keep a configuration file templated using just a basic (non-extensive but extensible) set of pillar values.
+
+On the reusability of SaltStack state files
+-------------------------------------------
+
+There is a brilliant initiative of the SaltStack community called `salt-formulas <https://github.com/saltstack-formulas>`_. Their goal is to provide state files, pillar examples and configuration templates ready to be used for provisioning. I am a contributor for two small ones: `zabbix-formula <https://github.com/saltstack-formulas/zabbix-formula>`_ and `varnish-formula <https://github.com/saltstack-formulas/varnish-formula>`_.
+
+The `design guidelines <http://docs.saltstack.com/en/latest/topics/development/conventions/formulas.html>`_ for formulas are clear in many aspects and it is a recommended reading for anyone willing to write state files, even non-formulaic ones.
+
+In the next section, I am going to describe my proposal to extend further the reusability of formulas, suggesting some patterns of usage.
+
+The Template Override and Files Switch (TOFS) pattern
+-----------------------------------------------------
+
+I understand a formula as a **complete, independent set of SaltStack state and configuration template files sufficient to configure a system**. A system could be something as simple as an NTP server or some other much more complex service that requires many state and configuration template files.
+
+The customization of a formula should be done mainly by providing pillar data used later to render either the state or the configuration template files.
+
+Example: NTP before applying TOFS
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Let's work with the NTP example. A basic formula that follows the `design guidelines <http://docs.saltstack.com/en/latest/topics/development/conventions/formulas.html>`_ has the following files and directories tree:
+
+.. code-block::
+
+   /srv/saltstack/salt-formulas/ntp-saltstack-formula/
+     ntp/
+       map.jinja
+       init.sls
+       conf.sls
+       files/
+         default/
+           etc/
+             ntp.conf.jinja
+
+In order to use it, let's assume a `masterless configuration <http://docs.saltstack.com/en/latest/topics/tutorials/quickstart.html>`_ and this relevant section of ``/etc/salt/minion``:
+
+.. code-block:: yaml
+
+   pillar_roots:
+     base:
+       - /srv/saltstack/pillar
+   file_client: local
+   file_roots:
+     base:
+       - /srv/saltstack/salt
+       - /srv/saltstack/salt-formulas/ntp-saltstack-formula
+
+.. code-block:: jinja
+
+   {#- /srv/saltstack/salt-formulas/ntp-saltstack-formula/ntp/map.jinja #}
+   {%- set ntp = salt['grains.filter_by']({
+     'default': {
+       'pkg': 'ntp',
+       'service': 'ntp',
+       'config': '/etc/ntp.conf',
+     },
+   }, merge=salt['pillar.get']('ntp:lookup')) %}
+
+In ``init.sls`` we have the minimal states required to have NTP configured. In many cases ``init.sls`` is almost equivalent to an ``apt-get install`` or a ``yum install`` of the package.
+
+.. code-block:: sls
+
+   ## /srv/saltstack/salt-formulas/ntp-saltstack-formula/ntp/init.sls
+   {%- from 'ntp/map.jinja' import ntp with context %}
+
+   Install NTP:
+     pkg.installed:
+       - name: {{ ntp.pkg }}
+
+   Enable and start NTP:
+     service.running:
+       - name: {{ ntp.service }}
+       - enabled: True
+       - require:
+         - pkg: Install NTP package
+
+In ``conf.sls`` we have the configuration states. In most cases, that is just managing configuration file templates and making them to be watched by the service.
+
+.. code-block:: sls
+
+   ## /srv/saltstack/salt-formulas/ntp-saltstack-formula/ntp/conf.sls
+   include:
+     - ntp
+
+   {%- from 'ntp/map.jinja' import ntp with context %}
+
+   Configure NTP:
+     file.managed:
+       - name: {{ ntp.config }}
+       - template: jinja
+       - source: salt://ntp/files/default/etc/ntp.conf.jinja
+       - watch_in:
+         - service: Enable and start NTP service
+       - require:
+         - pkg: Install NTP package
+
+Under ``files/default``, there is a structure that mimics the one in the minion in order to avoid clashes and confusion on where to put the needed templates. There you can find a mostly standard template for the configuration file.
+
+.. code-block:: jinja
+
+   {#- /srv/saltstack/salt-formulas/ntp-saltstack-formula/ntp/files/default/etc/ntp.conf.jinja #}
+   {#- Managed by saltstack #}
+   {#- Edit pillars or override this template in saltstack if you need customization #}
+   {%- set settings = salt['pillar.get']('ntp', {}) %}
+   {%- set default_servers = ['0.ubuntu.pool.ntp.org',
+                             '1.ubuntu.pool.ntp.org',
+                             '2.ubuntu.pool.ntp.org',
+                             '3.ubuntu.pool.ntp.org'] %}
+
+   driftfile /var/lib/ntp/ntp.drift
+   statistics loopstats peerstats clockstats
+   filegen loopstats file loopstats type day enable
+   filegen peerstats file peerstats type day enable
+   filegen clockstats file clockstats type day enable
+
+   {%- for server in settings.get('servers', default_servers) %}
+   server {{ server }}
+   {%- endfor %}
+
+   restrict -4 default kod notrap nomodify nopeer noquery
+   restrict -6 default kod notrap nomodify nopeer noquery
+
+   restrict 127.0.0.1
+   restrict ::1
+
+With all this, it is easy to install and configure a simple NTP server by just running ``salt-call state.sls ntp.conf``: the package will be installed, the service will be running and the configuration should be correct for most of cases, even without pillar data.
+
+Alternatively, you can define a highstate in ``/srv/saltstack/salt/top.sls`` and run ``salt-call state.highstate``.
+
+.. code-block:: sls
+
+   ## /srv/saltstack/salt/top.sls
+   base:
+     '*':
+       - ntp.conf
+
+**Customizing the formula just with pillar data**, we have the option to define the NTP servers.
+
+.. code-block:: sls
+
+   ## /srv/saltstack/pillar/top.sls
+   base:
+     '*':
+       - ntp
+
+.. code-block:: sls
+
+   ## /srv/saltstack/pillar/ntp.sls
+   ntp:
+     servers:
+       - 0.ch.pool.ntp.org
+       - 1.ch.pool.ntp.org
+       - 2.ch.pool.ntp.org
+       - 3.ch.pool.ntp.org
+
+Template Override
+^^^^^^^^^^^^^^^^^
+
+If the customization based on pillar data is not enough, we can override the template by creating a new one in ``/srv/saltstack/salt/ntp/files/default/etc/ntp.conf.jinja``
+
+.. code-block:: jinja
+
+   {#- /srv/saltstack/salt/ntp/files/default/etc/ntp.conf.jinja #}
+   {#- Managed by saltstack #}
+   {#- Edit pillars or override this template in saltstack if you need customization #}
+
+   {#- Some bizarre configurations here #}
+   {#- ... #}
+
+   {%- for server in settings.get('servers', default_servers) %}
+   server {{ server }}
+   {%- endfor %}
+
+This way we are locally **overriding the template files** offered by the formula in order to make a more complex adaptation. Of course, this could be applied as well to any of the files, including the state files.
+
+Files Switch
+^^^^^^^^^^^^
+
+To bring some order into the set of template files included in a formula, as we commented, we suggest having a similar structure to a normal final file system under ``files/default``.
+
+We can make different templates coexist for different minions, classified by any `grain <http://docs.saltstack.com/en/latest/topics/targeting/grains.html>`_ value, by simply creating new directories under ``files``. This mechanism is based on **using values of some grains as a switch for the directories under** ``files/``.
+
+If we decide that we want ``os_family`` as switch, then we could provide the formula template variants for both the ``RedHat`` and ``Debian`` families.
+
+.. code-block::
+
+   /srv/saltstack/salt-formulas/ntp-saltstack-formula/ntp/files/
+     default/
+       etc/
+         ntp.conf.jinja
+     RedHat/
+       etc/
+         ntp.conf.jinja
+     Debian/
+       etc/
+         ntp.conf.jinja
+
+To make this work we need a ``conf.sls`` state file that takes a list of possible files as the configuration template.
+
+.. code-block:: sls
+
+   ## /srv/saltstack/salt-formulas/ntp-saltstack-formula/ntp/conf.sls
+   include:
+     - ntp
+
+   {%- from 'ntp/map.jinja' import ntp with context %}
+
+   Configure NTP:
+     file.managed:
+       - name: {{ ntp.config }}
+       - template: jinja
+       - source:
+         - salt://ntp/files/{{ grains.get('os_family', 'default') }}/etc/ntp.conf.jinja
+         - salt://ntp/files/default/etc/ntp.conf.jinja
+       - watch_in:
+         - service: Enable and start NTP service
+       - require:
+         - pkg: Install NTP package
+
+If we want to cover the possibility of a special template for a minion identified by ``node01`` then we could have a specific template in ``/srv/saltstack/salt/ntp/files/node01/etc/ntp.conf.jinja``.
+
+.. code-block:: jinja
+
+   {#- /srv/saltstack/salt/ntp/files/node01/etc/ntp.conf.jinja #}
+   {#- Managed by saltstack #}
+   {#- Edit pillars or override this template in saltstack if you need customization #}
+
+   {#- Some crazy configurations here for node01 #}
+   {#- ... #}
+
+To make this work we could write a specially crafted ``conf.sls``.
+
+.. code-block:: sls
+
+   ## /srv/saltstack/salt-formulas/ntp-saltstack-formula/ntp/conf.sls
+   include:
+     - ntp
+
+   {%- from 'ntp/map.jinja' import ntp with context %}
+
+   Configure NTP:
+     file.managed:
+       - name: {{ ntp.config }}
+       - template: jinja
+       - source:
+         - salt://ntp/files/{{ grains.get('id') }}/etc/ntp.conf.jinja
+         - salt://ntp/files/{{ grains.get('os_family') }}/etc/ntp.conf.jinja
+         - salt://ntp/files/default/etc/ntp.conf.jinja
+       - watch_in:
+         - service: Enable and start NTP service
+       - require:
+         - pkg: Install NTP package
+
+Using the ``files_switch`` macro
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+We can simplify the ``conf.sls`` with the new ``files_switch`` macro to use in the ``source`` parameter for the ``file.managed`` state.
+
+.. code-block:: sls
+
+   ## /srv/saltstack/salt-formulas/ntp-saltstack-formula/ntp/conf.sls
+   include:
+     - ntp
+
+   {%- set tplroot = tpldir.split('/')[0] %}
+   {%- from 'ntp/map.jinja' import ntp with context %}
+   {%- from 'ntp/libtofs.jinja' import files_switch %}
+
+   Configure NTP:
+     file.managed:
+       - name: {{ ntp.config }}
+       - template: jinja
+       - source: {{ files_switch(['/etc/ntp.conf.jinja'],
+                                 lookup='Configure NTP'
+                    )
+                 }}
+       - watch_in:
+         - service: Enable and start NTP service
+       - require:
+         - pkg: Install NTP package
+
+
+* This uses ``config.get``, searching for ``ntp:tofs:source_files:Configure NTP`` to determine the list of template files to use.
+* If this does not yield any results, the default of ``['/etc/ntp.conf.jinja']`` will be used.
+
+In ``libtofs.jinja``, we define this new macro ``files_switch``.
+
+.. literalinclude:: ../template/libtofs.jinja
+   :caption: /srv/saltstack/salt-formulas/ntp-saltstack-formula/ntp/libtofs.jinja
+   :language: jinja
+
+How to customise the ``source`` further
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The examples below are based on an ``Ubuntu`` minion called ``theminion`` being configured via. pillar.
+
+Using the default settings of the ``files_switch`` macro above,
+the ``source`` will be:
+
+.. code-block:: sls
+
+         - source:
+           - salt://ntp/files/theminion/etc/ntp.conf.jinja
+           - salt://ntp/files/Debian/etc/ntp.conf.jinja
+           - salt://ntp/files/default/etc/ntp.conf.jinja
+
+Customise ``files``
+~~~~~~~~~~~~~~~~~~~
+
+The ``files`` portion can be customised:
+
+.. code-block:: sls
+
+   ntp:
+     tofs:
+       dirs:
+         files: files_alt
+
+Resulting in:
+
+.. code-block:: sls
+
+         - source:
+           - salt://ntp/files_alt/theminion/etc/ntp.conf.jinja
+           - salt://ntp/files_alt/Debian/etc/ntp.conf.jinja
+           - salt://ntp/files_alt/default/etc/ntp.conf.jinja
+
+Customise the use of grains
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Grains can be customised and even arbitrary paths can be supplied:
+
+.. code-block:: sls
+
+   ntp:
+     tofs:
+       files_switch:
+         - any/path/can/be/used/here
+         - id
+         - os
+         - os_family
+
+Resulting in:
+
+.. code-block:: sls
+
+         - source:
+           - salt://ntp/files/any/path/can/be/used/here/etc/ntp.conf.jinja
+           - salt://ntp/files/theminion/etc/ntp.conf.jinja
+           - salt://ntp/files/Ubuntu/etc/ntp.conf.jinja
+           - salt://ntp/files/Debian/etc/ntp.conf.jinja
+           - salt://ntp/files/default/etc/ntp.conf.jinja
+
+Customise the ``default`` path
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The ``default`` portion of the path can be customised:
+
+.. code-block:: sls
+
+   ntp:
+     tofs:
+       dirs:
+         default: default_alt
+
+Resulting in:
+
+.. code-block:: sls
+
+         - source:
+           ...
+           - salt://ntp/files/default_alt/etc/ntp.conf.jinja
+
+Customise the list of ``source_files``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The list of ``source_files`` can be given:
+
+.. code-block:: sls
+
+   ntp:
+     tofs:
+       source_files:
+         Configure NTP:
+           - '/etc/ntp.conf.jinja'
+           - '/etc/ntp.conf_alt.jinja'
+
+Resulting in:
+
+.. code-block:: sls
+
+         - source:
+           - salt://ntp/files/theminion/etc/ntp.conf.jinja
+           - salt://ntp/files/theminion/etc/ntp.conf_alt.jinja
+           - salt://ntp/files/Debian/etc/ntp.conf.jinja
+           - salt://ntp/files/Debian/etc/ntp.conf_alt.jinja
+           - salt://ntp/files/default/etc/ntp.conf.jinja
+           - salt://ntp/files/default/etc/ntp.conf_alt.jinja
+

keepalived/config.sls

-keepalived.config:
- file.managed:
-   - name: {{ salt['pillar.get']('keepalived:config_file_path', '/etc/keepalived/keepalived.conf') }}
-   - source: salt://keepalived/templates/keepalived.jinja
-   - template: jinja
-   - user: root
-   - group: root
-   - mode: 644

keepalived/config/file.sls

+# -*- coding: utf-8 -*-
+# vim: ft=sls
+
+{#- Get the `tplroot` from `tpldir` #}
+{%- set tplroot = tpldir.split('/')[0] %}
+{%- set sls_package_install = tplroot ~ '.package.install' %}
+{%- from tplroot ~ "/map.jinja" import keepalived with context %}
+{%- from tplroot ~ "/libtofs.jinja" import files_switch with context %}
+
+include:
+  - {{ sls_package_install }}
+
+keepalived-config-file-file-managed:
+  file.managed:
+    - name:     {{ keepalived.config_file }}
+    - user:     root
+    - group:    root
+    - template: jinja
+    - source: {{ files_switch(['keepalived.conf.tmpl', 'keepalived.conf.tmpl.jinja'],
+                              lookup='keepalived-config-file-file-managed'
+                 )
+              }}
+    - require:
+      - sls: {{ sls_package_install }}
+    - context:
+        config: {{ keepalived.config | json }}

keepalived/config/init.sls

+# -*- coding: utf-8 -*-
+# vim: ft=sls
+
+include:
+  - .file

keepalived/defaults.yaml

+# -*- coding: utf-8 -*-
+# vim: ft=yaml
 ---
-# keepalived/defaults.yaml
-
+keepalived:
+  package: keepalived
+  config_file: /etc/keepalived/keepalived.conf
+  service:
+    name: keepalived
+  config:
     global_defs:
       smtp_server: localhost

keepalived/files/default/keepalived.conf.tmpl.jinja

+########################################################################
+# File managed by Salt at <{{ source }}>.
+# Your changes will be overwritten.
+########################################################################
+
+{%- from "keepalived/macro.jinja" import print_config %}
+{%- set sections = ['global_defs', 'vrrp_script', 'vrrp_instance', 'virtual_server'] %}
+{%- for section in sections %}
+{{ print_config({ section: config[section] }) }}
+{%- endfor %}

keepalived/init.sls

-# keepalived
-#
-# Meta-state to fully setup keepalived on debian. (or any other distro that has keepalived in their repo)
+# -*- coding: utf-8 -*-
+# vim: ft=sls
 
 include:
-  - keepalived.install
-  - keepalived.service
-  - keepalived.config
+  - .package
+  - .config
+  - .service

keepalived/install.sls

-keepalived.install:
-  pkg.installed:
-    - name: keepalived

keepalived/libtofs.jinja

+{%- macro files_switch(source_files,
+                       lookup=None,
+                       default_files_switch=['id', 'os_family'],
+                       indent_width=6,
+                       v1_path_prefix='') %}
+  {#-
+    Returns a valid value for the "source" parameter of a "file.managed"
+    state function. This makes easier the usage of the Template Override and
+    Files Switch (TOFS) pattern.
+
+    Params:
+      * source_files: ordered list of files to look for
+      * lookup: key under '<tplroot>:tofs:source_files' to override
+        list of source files
+      * default_files_switch: if there's no config (e.g. pillar)
+        '<tplroot>:tofs:files_switch' this is the ordered list of grains to
+        use as selector switch of the directories under
+        "<path_prefix>/files"
+      * indent_witdh: indentation of the result value to conform to YAML
+      * v1_path_prefix: (deprecated) only used for injecting a path prefix into
+        the source, to support older TOFS configs
+
+    Example (based on a `tplroot` of `xxx`):
+
+    If we have a state:
+
+      Deploy configuration:
+        file.managed:
+          - name: /etc/yyy/zzz.conf
+          - source: {{ files_switch(['/etc/yyy/zzz.conf', '/etc/yyy/zzz.conf.jinja'],
+                                    lookup='Deploy configuration'
+                    ) }}
+          - template: jinja
+
+    In a minion with id=theminion and os_family=RedHat, it's going to be
+    rendered as:
+
+      Deploy configuration:
+        file.managed:
+          - name: /etc/yyy/zzz.conf
+          - source:
+            - salt://xxx/files/theminion/etc/yyy/zzz.conf
+            - salt://xxx/files/theminion/etc/yyy/zzz.conf.jinja
+            - salt://xxx/files/RedHat/etc/yyy/zzz.conf
+            - salt://xxx/files/RedHat/etc/yyy/zzz.conf.jinja
+            - salt://xxx/files/default/etc/yyy/zzz.conf
+            - salt://xxx/files/default/etc/yyy/zzz.conf.jinja
+          - template: jinja
+  #}
+  {#- Get the `tplroot` from `tpldir` #}
+  {%- set tplroot = tpldir.split('/')[0] %}
+  {%- set path_prefix = salt['config.get'](tplroot ~ ':tofs:path_prefix', tplroot) %}
+  {%- set files_dir = salt['config.get'](tplroot ~ ':tofs:dirs:files', 'files') %}
+  {%- set files_switch_list = salt['config.get'](
+      tplroot ~ ':tofs:files_switch',
+      default_files_switch
+  ) %}
+  {#- Lookup source_files (v2), files (v1), or fallback to source_files parameter #}
+  {%- set src_files = salt['config.get'](
+      tplroot ~ ':tofs:source_files:' ~ lookup,
+      salt['config.get'](
+          tplroot ~ ':tofs:files:' ~ lookup,
+          source_files
+      )
+  ) %}
+  {#- Only add to [''] when supporting older TOFS implementations #}
+  {%- set path_prefix_exts = [''] %}
+  {%- if v1_path_prefix != '' %}
+    {%- do path_prefix_exts.append(v1_path_prefix) %}
+  {%- endif %}
+  {%- for path_prefix_ext in path_prefix_exts %}
+    {%- set path_prefix_inc_ext = path_prefix ~ path_prefix_ext %}
+    {#- For older TOFS implementation, use `files_switch` from the config #}
+    {#- Use the default, new method otherwise #}
+    {%- set fsl = salt['config.get'](
+        tplroot ~ path_prefix_ext|replace('/', ':') ~ ':files_switch',
+        files_switch_list
+    ) %}
+    {#- Append an empty value to evaluate as `default` in the loop below #}
+    {%- if '' not in fsl %}
+      {%- do fsl.append('') %}
+    {%- endif %}
+    {%- for fs in fsl %}
+      {%- for src_file in src_files %}
+        {%- if fs %}
+          {%- set fs_dir = salt['config.get'](fs, fs) %}
+        {%- else %}
+          {%- set fs_dir = salt['config.get'](tplroot ~ ':tofs:dirs:default', 'default') %}
+        {%- endif %}
+        {%- set url = '- salt://' ~ '/'.join([
+            path_prefix_inc_ext,
+            files_dir,
+            fs_dir,
+            src_file.lstrip('/')
+        ]) %}
+{{ url | indent(indent_width, true) }}
+      {%- endfor %}
+    {%- endfor %}
+  {%- endfor %}
+{%- endmacro %}

keepalived/templates/config.jinja → keepalived/macro.jinja

+# -*- coding: utf-8 -*-
+# vim: ft=jinja
+
 {%- set key = 0 -%}
 {%- set value = 1 -%}
-{%- set carryovers = ['real_server', 'virtual_server', 'virtual_server_group', 
-      'vrrp_instance', 'vrrp_script', 'vrrp_sync_group'] -%}
-{%- macro keepalived_config(data, carryover='', recurse=-1, indent=0) -%}
+{%- set carryovers = ['real_server', 'virtual_server', 'virtual_server_group', 'vrrp_instance', 'vrrp_script', 'vrrp_sync_group'] -%}
+
+{%- macro print_config(data, carryover='', recurse=-1, indent=0) -%}
   {%- set recurse = recurse + 1 -%}
   {%- if data is none -%}
     {{- '\n' -}}
@@ -16,7 +19,7 @@
     {%- if data is mapping -%}
       {%- for item in data|dictsort -%}
         {%- if item[key] in carryovers -%}
-          {{- keepalived_config(item[value], carryover=item[key], indent=indent) -}}
+          {{- print_config(item[value], carryover=item[key], indent=indent) -}}
         {%- else -%}
           {%- set carryIndent = indent -%}
           {%- set forwardIndent = indent -%}
@@ -27,12 +30,12 @@
           {%- if item[value] is string or item[value] is not iterable -%}
             {%- set forwardIndent = 0 -%}
           {%- endif -%}
-          {{- item[key]|indent(carryIndent, True) }} {{ keepalived_config(item[value], recurse=recurse, indent=forwardIndent) -}}
+          {{- item[key]|indent(carryIndent, True) }} {{ print_config(item[value], recurse=recurse, indent=forwardIndent) -}}
         {%- endif -%}
       {%- endfor -%}
     {%- else -%}
       {%- for item in data -%}
-        {{- keepalived_config(item, indent=indent) -}}
+        {{- print_config(item, indent=indent) -}}
       {%- endfor -%}
     {%- endif -%}
     {%- if recurse > 0 -%}

keepalived/map.jinja

+# -*- coding: utf-8 -*-
+# vim: ft=jinja
+
+{#- Get the `tplroot` from `tpldir` #}
+{%- set tplroot = tpldir.split('/')[0] %}
+{#- Start imports as #}
+{%- import_yaml tplroot ~ "/defaults.yaml" or {} as default_settings %}
+{%- import_yaml tplroot ~ "/osfamilymap.yaml" or {} as osfamilymap %}
+{%- import_yaml tplroot ~ "/osmap.yaml" or {} as osmap %}
+{%- import_yaml tplroot ~ "/osfingermap.yaml" or {} as osfingermap %}
+
+{%- set defaults = salt['grains.filter_by'](default_settings,
+  default='keepalived',
+  merge=salt['grains.filter_by'](osfamilymap, grain='os_family',
+    merge=salt['grains.filter_by'](osmap, grain='os',
+      merge=salt['grains.filter_by'](osfingermap, grain='osfinger',
+        merge=salt['pillar.get']('keepalived:lookup', default={})
+      )
+    )
+  )
+) %}
+
+{#- Merge the keepalived pillar #}
+{%- set keepalived = salt['pillar.get']('keepalived', default=defaults, merge=True) %}