Add Chrony Plugin

[dusharu]

Feature request

Please, add support for chrony plugin.

Reason

In RHEL Linux 8, the ntp package is no longer supported and it is implemented by the chronyd (a daemon that runs in user-space) which is provided in the chrony package.

Manual add chrony

Now, we are using this code to add collectd-chrony to our servers.
May be it be useful for somebody.

my_collectd.pp

  if defined(Class['chrony']) {
    ensure_packages (collectd-chrony, {
      ensure  => 'present',
    })

    ensure_resource('file','/etc/collectd.d/10-chrony.conf',{
      ensure  => file,
      owner   => 'root',
      group   => 'root',
      mode    => '0640',
      source  => "puppet:///modules/${module_name}/collectd/10-chrony.conf",
      require => Package[collectd-chrony],
      notify  => Service['collectd'],
    })

    class { 'collectd::plugin::ntpd':
      ensure => absent
    }
  }

10-chrony.conf

# Generated by Puppet
<LoadPlugin chrony>
  Globals false
</LoadPlugin>

<Plugin chrony>
  Host "localhost"
  Port "323"
</Plugin>