Possible fanout syntax

gistfile1.txt

   [groups.bastions.hosts]
    "bastion.example.com" = ""

    [groups.rack1.hosts]
    "rack1-top.example.com" = "opsmop_via=bastion.example.com"
    "rack1-101.example.com" = ""
    "rack1-102.example.com" = ""

    [groups.rack2.hosts]
    "rack2-top.example.com" = "opsmop_via=bastion.example.com"
    "rack2-201.example.com" = ""
    "rack2-202.example.com" = ""

    [groups.rack1.vars]
    opsmop_via = "rack1-top.example.com"

    [groups.rack2.vars]
    opsmop_via = "rack2-top.example.com"

    [groups.fooapp.hosts]
    "rack1-101.example.com" = ""
    "rack2-202.example.com" = ""

    [groups.barapp.hosts]
    "rack2-102.example.com" = ""