Enhancement/icinga2 zones conf

[Donien]

This is currently still work in progress.

This PR will introduce a simple variable (nested dictionary) to define the zone hierarchy.

The corresponding action plugin creates the zones and endpoints for each host according to the variable.
Each host will only know those zones and endpoints it has to know.

Example:

icinga2_zones_conf:
  hierarchy:
    master: # Could be inventory_hostname or Ansible group name
      germany:
        berlin1:
        berlin2:
      france:
        paris:

From this, the plugin will create zones and endpoints based on available variables.
It only returns information. Using the information is still up to the role!

---

Feedback

There is still a need for a proper way to define variables which will be used for the endpoints host attribute.

2 hosts could have the same parent but in different networks (2 firewall zones for example).
We must be able to provide some kind of mapping to tell a given host the correct address when it wants to access its parent.

• Master A
• Satellite B in firewall zone 1
• Satellite C in firewall zone 2

If B wants to access A, it needs IP-1.
If C wants to access A, it needs IP-2.

This mapping must be defined somewhere.

As a fallback, we can always use inventory_hostname.