* Added Archlinux as supported OS

Signed-off-by: bjanssens <bjanssens@inuits.eu>

Signed-off-by: bjanssens <bjanssens@inuits.eu>

* "On Ubuntu 14.04, redis has an init script 
that does chown redis:redis $RUNDIR $PIDFILE 
(where RUNDIR=/var/run/redis and 
PIDFILE=$RUNDIR/redis-server.pid) at startup. 
This causes puppet to "fix" the ownership of 
/var/run/redis (to redis:root unless config_owner 
and config_group have been set differently), 
which triggers a restart of redis-server, 
which changes the ownership of /var/run/redis, 
etc. forever.
* Closes #150

* New style guide rule: 
https://docs.puppet.com/puppet/latest/style_guide.html#chaining-arrow-syntax

* Older Redis has different version string
* Updated with spec and tests

* Upstream CentOS images run slowly on mac
* These images have no issues

* Previously we were changing some of the default 
configurations from the upstream packages
* This causes issues with CentOS 6 services, and 
needlessly clutters logs.
* Change to follow ownership patterns of 
original packages:
  * Changes service group to be root
  * Change workdir permission
  * Change pid file location back to package default
* Adds failing Travis check for CentOS 6

Copy paste error from the Collectd module!

* rundir directories are 2775
* e.g.  from the postgres init.d script:
```
 if [ -d /var/run/postgresql ]; then
        chmod 2775 /var/run/postgresql
    else
        install -d -m 2775 -o postgres -g postgres /var/run/postgresql
    fi
```

* When installing sentinel on the same node as redis, duplicate 
declaration error occurs
* This is because it was originally wrapped in an ensure_resource 
* This was removed in b5174b2
* We should also remove the sentinel ensure_resource
* This was originally added because Debian machines have a dedicated
redid-sentinel package, whereas RedHat flavour machines do not
* Instead, include the redis class so we have the variables we need
* Add logic installing the redid-sentinel package on Debian-flavour
* See #18 for more context

* Slight refactoring and DRY-ing up of code
* No logic changes

* See travis-ci/travis-ci#7685

* Explicitly set packages after apt install
* Change includes to contains

Add the redisget() function which can get a value for a specified key
from a specified redis URL.

* Redis 2.4.10 is old in software terms (2014)
* Redis will refuse to start 
* The amount of logic that would have to be added
to the template to isolate new config values would
be hard to maintain
* For now, lets just have a CentOS 6 specific erb
* Adds spec to check also
* Changes acceptance test for sentinel to not
run on CentOS 6
* Adds function for Puppet 3/4 compatibility with the fact

* Ignore more of the usual bits

* (style) Remove unused exceptions for puppet-lint

* (style) puppet-lint to ignore lines with more than 140 characters

* (style) README to comply with style

Instead of anding all the commands together, we can pass them each to
bundle exec, which achieves the same results.

* Location on Debian-like systems is `/etc/redis/sentinel.conf`

* redis-sentinel is present in upstream repos
* It's also present for 16.04/xenial onwards
* So lets only manage that package if we're on
Ubuntu newer or if we're managing the repo

* Allows modification of common redis kernel
tweaks and requirements
* The ones that antirez (redis creator) mentions
and that are mentioned specifically in redis 
when running it in the logs are:
  * Disable THP: https://redis.io/topics/latency
  * Enable Overcommit Memory: https://redis.io/topics/admin
  * somaxconnL http://download.redis.io/redis-stable/redis.conf

* We say we support 1404, but aren't testing
* But 1404 has an older package, and certain 
config settings aren't present (See #111)
* Add 2.8.X config file and logic to fix that
* Add to CI, add docker and vagrant SUTs

* Remove point releases

Release candidate for the 3.0.0 release

This will be the last release that supports 
Puppet 3.X

Version 4.x of the module onward will remove 3.X support

* This is done at a class level in init.pp
* Do not need to specify individual service

* Changing Travis back to Trusty

* Improves ulimit configuration

* Moves to a dedicated class to DRY up config.pp
* Adds support for systemd systems:
 - /etc/systemd/system/redis.service.d/limit.conf
* Add support for redis when used with a cluster
manager such as pacemaker or rgmanager
* New parameter `managed_by_cluster_manager`
* This manages the file under:
```
/etc/security/limits.d/redis.conf
```
* Closes #130

* If the redis service is unmanaged, like so:
```
redis::managed_by_cluster_manager": true
redis::service_manage": false
redis::notify_service": false
```
then you get a compilation failure as it tries to
look for the redis service to notify:
```
But now an 'include ::redis' gives me:
Error: Could not find dependent Service[redis] for Augeas[Systemd redis ulimit] at /etc/puppet/modules/redis/manifests/ulimit.pp:44
```
* In fact, we don't need any service notification 
in the redis::ulimit class, as it's already in the
redis::config class, which notifies the service 
class anyways
* Adds spec for this use-case to avoid regression

Closes #197

* With the previous approach, error on 1.8.7 Ruby:
```
Error: Failed to parse template redis/redis.conf.2.4.10.erb:
  Filepath: /etc/puppet/modules/redis/templates/redis.conf.2.4.10.erb
  Line: 87
  Detail: undefined method `<=>' for nil:NilClass
 at /etc/puppet/modules/redis/manifests/config.pp:91 on node master
```
* For ruby 1.8 compatibility
* Should fix older Puppet on systems that have 
1.8.7 Ruby (RHEL6/CentOS6)
* We're not officially supporting 1.8.7 as it's 
EOL, but since this is a minor change, isn't too 
much of a maintenance cost, lets do it! 💃