'in' expresion matches substrings, therefore it is possible
that following expression will fail:
inventory_hostname in groups['groupname'][0]
for example when:
inventory_hostname = 'my-host-a'
groups['groupname'][0] = 'my-host-a1'
The result is running task on multiple hosts rather than single one.
Such action might result in playbook failure
Change-Id: Ibe2d5ca2f9502a8140a895ab3ac7abc5076ce2ff
Signed-off-by: Maciej Kucia <m.kucia@partner.samsung.com>