Comment 3 for bug 1536083

The problem is this part of the patch

+ has_ipv6 = ipv6_is_enabled
 + if has_ipv6
 + ipv6 = '--ipv6'
 + else
 + ipv6 = ''
 + end
      out = nil
      retry_count.times do |n|
        begin
          if host
 - out = mongo([db, '--quiet', '--host', host, '--eval', cmd])
 + out = mongo([db, '--quiet', ipv6, '--host', host, '--eval', cmd])

if ipv6 == "", the mongo command is being run with a blank parameter, its interpreting this as the name of a file which it can't open

[root@overcloud-controller-0 mongodb]# /bin/mongo admin --quiet "" --host 192.0.2.22:27017 --eval "printjson(rs.conf())"
{
        "_id" : "tripleo",
        "version" : 1,
        "members" : [
                {
                        "_id" : 0,
                        "host" : "192.0.2.22:27017"
                }
        ]
}
2016-01-20T12:42:02.127+0000 file [] doesn't exist
failed to load:
[root@overcloud-controller-0 mongodb]# echo $?
253