Add support for shared ansible_host in inventory

Today it is possible to create the following ansible inventory file:

  [foo]
  foo01 ansible_host=192.168.1.1

  [bar]
  bar01 ansible_host=192.168.1.1

Which allows a user to create multiple host aliases for a single
connection. This could be done with ansible groups, however there is
some functional differences on how ansible runs in that configuration.

We could also request 2 nodes from nodepool, however in this case, it
would be a waste of CI resources because every alias would need a new
node from nodepool.

Now, a user is able to alias multiple host names to a single node from
nodepool by doing the following:

  nodeset:
    nodes:
      - name:
          - foo
          - bar
        label: ubuntu-xenial

This would result in a single node request from nodepool, but create
an inventory file with 2 alaises sharing and single ansible_host
variable.

Change-Id: I674d6baac26852ee1503feb1ed16c279bf773688
Signed-off-by: Paul Belanger <pabelanger@redhat.com>
9 files changed