Fix openstack inventory for when we have multiple servers with the same
name but different IDs. Instead of giving every server with the same
name the details for the first server returned with that name add the
individual servers as they are returned.
This was a logic bug where in a loop over a list of servers we always
added the first server in that list despite having more than one server.
EC2 inventory scripts reads configuration from an INI file. The `instance_filters` option controls which EC2 instances are retrieved for inventory. Filling this option and running the inventory script with Python 3 crashes with the following error:
```python
Traceback (most recent call last):
File "./contrib/inventory/ec2.py", line 1328, in <module>
Ec2Inventory()
File "./contrib/inventory/ec2.py", line 163, in __init__
self.read_settings()
File "./contrib/inventory/ec2.py", line 393, in read_settings
for instance_filter in config.get('ec2', 'instance_filters', '').split(','):
TypeError: get() takes 3 positional arguments but 4 were given
```
The problem is the last parameter of config.get() call, because `fallback` keyword argument is not specified.
The fix handles epmpty `instance_filers` in case of Python 2&3
There are cases where the host list back from the cloud comes back
duplicated. This causes us to report those with UUIDs, which we do to
support truly different servers with the same name. However, in the case
where duplicate host entries have the same UUID, we can know it's a data
hiccup.
The OpenStack inventory lists hostnames as the UUIDs because hostsnames
are not guarnateed to be unique on OpenStack. However, for the common
case, this is just confusing.
The new behavior is a visible change, so make it an opt-in via config.
Only turn the hostnames to UUIDs if there are duplicate hostnames.
If enabled, this will convert tags of the form "a,b,c" to a list and use
the results to create additional inventory groups.
This is based on PR #8676 by nickpeck (but not a straight rebase—both
the code and the nomenclature have been changed here).
Closes#8676