Bug 1266467

Description of problem:
the following trace is raised durring the discovery of a vmware host :

----] I, [2015-09-24T10:12:09.962683 #29004:f9c004]  INFO -- : MIQ(MiqQueue.get_via_drb) Message id: [1000013723294], MiqWorker id: [1000000035466], Zone: [default], Role: [], Server: [a5baafc6-f944-11e4-a312-00505635f697], Ident: [generic], Target id: [], Instance id:
[], Task id: [], Command: [Host.discoverHost], Timeout: [600], Priority: [100], State: [dequeue], Deliver On: [], Data: [90 bytes], Args: [], Dequeued in: [4.413938949] seconds
[----] I, [2015-09-24T10:12:09.962822 #29004:f9c004]  INFO -- : MIQ(MiqQueue.deliver)    Message id: [1000013723294], Delivering...
[----] I, [2015-09-24T10:12:10.021925 #29004:f9c004]  INFO -- : MIQ(host-discoverHost): Discovering Host: #<OpenStruct ipaddr="172.16.135.4", usePing=nil, timeout=10, discover_types=[:esx]>
[----] D, [2015-09-24T10:12:10.778346 #29004:f9c004] DEBUG -- : WindowsProbe: probing ip = 172.16.135.4
[----] D, [2015-09-24T10:12:20.779930 #29004:f9c004] DEBUG -- : PortScan: ip = 172.16.135.4, port = 135, execution expired
[----] D, [2015-09-24T10:12:30.781245 #29004:f9c004] DEBUG -- : PortScan: ip = 172.16.135.4, port = 139, execution expired
[----] D, [2015-09-24T10:12:30.781404 #29004:f9c004] DEBUG -- : WindowsProbe: probe of ip = 172.16.135.4 complete
[----] D, [2015-09-24T10:12:30.788970 #29004:f9c004] DEBUG -- : Skipping VMwareServerProbe
[----] D, [2015-09-24T10:12:30.796501 #29004:f9c004] DEBUG -- : Skipping RedHatRhevmProbe
[----] D, [2015-09-24T10:12:30.818436 #29004:f9c004] DEBUG -- : VMwareEsxVcProbe: probing ip = 172.16.135.4
[----] D, [2015-09-24T10:12:33.215493 #29004:f9c004] DEBUG -- : VMwareEsxVcProbe: ip = 172.16.135.4, Connected to VMware webservice. Machine is either ESX or VirtualCenter.
[----] D, [2015-09-24T10:12:33.218058 #29004:f9c004] DEBUG -- : PortScan: ip = 172.16.135.4, port = 902, Found port
[----] D, [2015-09-24T10:12:43.219923 #29004:f9c004] DEBUG -- : PortScan: ip = 172.16.135.4, port = 135, execution expired
[----] D, [2015-09-24T10:12:53.221753 #29004:f9c004] DEBUG -- : PortScan: ip = 172.16.135.4, port = 7444, execution expired
[----] D, [2015-09-24T10:12:53.221900 #29004:f9c004] DEBUG -- : VMwareEsxVcProbe: ip = 172.16.135.4, Machine is an ESX server.
[----] D, [2015-09-24T10:12:53.221968 #29004:f9c004] DEBUG -- : VMwareEsxVcProbe: probe of ip = 172.16.135.4 complete
[----] I, [2015-09-24T10:12:53.231164 #29004:f9c004]  INFO -- : Skipping MS Hyper-V Probe
[----] D, [2015-09-24T10:12:53.237952 #29004:f9c004] DEBUG -- : Skipping MSVirtualServerProbe
[----] I, [2015-09-24T10:12:53.260920 #29004:f9c004]  INFO -- : Skipping IPMI Probe
[----] D, [2015-09-24T10:12:53.506686 #29004:f9c004] DEBUG -- : Skipping MSScvmmProbe
[----] I, [2015-09-24T10:12:53.507311 #29004:f9c004]  INFO -- : MIQ(host-discoverHost): Discovered: #<OpenStruct ipaddr="172.16.135.4", usePing=nil, timeout=10, discover_types=[:esx], os=[:linux], hypervisor=[:esx]>
[----] I, [2015-09-24T10:12:53.693227 #29004:f9c004]  INFO -- : MIQ(host-get_hostname): Resolving hostname: [172.16.135.4]
[----] I, [2015-09-24T10:12:53.693698 #29004:f9c004]  INFO -- : MIQ(host-get_hostname): Resolved hostname: [172.16.135.4] to [172.16.135.4]
[----] E, [2015-09-24T10:12:53.972740 #29004:f9c004] ERROR -- : [NameError]: undefined local variable or method `os_type' for #<Class:0x00000005a9b370>  Method:[rescue in discoverHost]
[----] E, [2015-09-24T10:12:53.972987 #29004:f9c004] ERROR -- : /opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.17/lib/active_record/dynamic_matchers.rb:55:in `method_missing'
/var/www/miq/vmdb/app/models/host.rb:1377:in `discoverHost'
/var/www/miq/vmdb/app/models/miq_queue.rb:361:in `block in deliver'
/opt/rh/ruby193/root/usr/share/ruby/timeout.rb:69:in `timeout'
/var/www/miq/vmdb/app/models/miq_queue.rb:357:in `deliver'
/var/www/miq/vmdb/lib/workers/queue_worker_base.rb:107:in `deliver_queue_message'
/var/www/miq/vmdb/lib/workers/queue_worker_base.rb:135:in `deliver_message'
/var/www/miq/vmdb/lib/workers/queue_worker_base.rb:152:in `block in do_work'
/var/www/miq/vmdb/lib/workers/queue_worker_base.rb:146:in `loop'
/var/www/miq/vmdb/lib/workers/queue_worker_base.rb:146:in `do_work'
/var/www/miq/vmdb/lib/workers/worker_base.rb:317:in `block in do_work_loop'
/var/www/miq/vmdb/lib/workers/worker_base.rb:314:in `loop'
/var/www/miq/vmdb/lib/workers/worker_base.rb:314:in `do_work_loop'
/var/www/miq/vmdb/lib/workers/worker_base.rb:135:in `run'
/var/www/miq/vmdb/lib/workers/worker_base.rb:123:in `start'
/var/www/miq/vmdb/lib/workers/worker_base.rb:23:in `start_worker'
/var/www/miq/vmdb/lib/workers/bin/worker.rb:5:in `<top (required)>'
/opt/rh/ruby193/root/usr/share/gems/gems/railties-3.2.17/lib/rails/commands/runner.rb:52:in `eval'
/opt/rh/ruby193/root/usr/share/gems/gems/railties-3.2.17/lib/rails/commands/runner.rb:52:in `<top (required)>'
/opt/rh/ruby193/root/usr/share/gems/gems/railties-3.2.17/lib/rails/commands.rb:64:in `require'
/opt/rh/ruby193/root/usr/share/gems/gems/railties-3.2.17/lib/rails/commands.rb:64:in `<top (required)>'
script/rails:6:in `require'
script/rails:6:in `<main>'

Version-Release number of selected component (if applicable):
cfme-5.3.4.2-1.el6cf.x86_64

How reproducible:
not reproduced in lab

Steps to Reproduce:
1. on customer appliance, make an attempt to add the host manually by discovering
2. 
3.

Actual results:
the host is added to the appliance by ip only, no information is added.

Expected results:
the host is added with no error

Additional info:
a dns is set to return the hostname and works in reverse as well.
normal discovery of the hypervisor does not see this host in the cluster it belongs to.