Version-Release number of selected component (if applicable):
@Sat6.2.0-Beta-Snap6

Created redmine issue http://projects.theforeman.org/issues/14570 from this bug

Moving to POST since upstream bug http://projects.theforeman.org/issues/14570 has been closed
-------------
Daniel Lobato Garcia
Applied in changeset commit:foreman-docker|2fbd23c328e4d0c90ea845e10eb3529135e41250.

FailedQA.

@satellite-6.2.0-13.0.el7sat.noarch
tfm-rubygem-foreman_docker-2.0.1.9-1.el7sat.noarch

Used reproducer in comment #0 and for contaner name 'container1' it is OK
But for container name 'centos_hub' it behaves still same 

Error: Name has already been taken

And "docker ps -a" show no such container so there should be no such error.
Problem could be that 'centos_hub' container at UI is displayed as "Centos Hub"
(i.e. with space)

Now even reproduced with simple container name "busybox"

1)
# docker ps -a
CONTAINER ID        IMAGE                          COMMAND                  CREATED             STATUS              PORTS               NAMES
e15da18670ed        satelliteqe/robottelo:latest   "python -m SimpleHTTP"   2 days ago          Up 2 days           22/tcp, 12345/tcp   container2

2) UI: creating "busybox" container

2016-05-26 07:48:05 [app] [I] Started PUT "/wizard_states/14/steps/environment" for 10.34.130.242 at 2016-05-26 07:48:05 -0400
2016-05-26 07:48:05 [app] [I] Processing by Containers::StepsController#update as HTML
2016-05-26 07:48:05 [app] [I]   Parameters: {"utf8"=>"✓", "authenticity_token"=>"Cqowi1wZonkqO3cOzYbZ3ObizudoJypwnRIbgI/519c=", "docker_container_wizard_states_environment"=>{"tty"=>"0", "attach_stdin"=>"1", "attach_stdout"=>"1", "attach_stderr"=>"1"}, "button"=>"", "wizard_state_id"=>"14", "id"=>"environment"}
2016-05-26 07:48:05 [app] [I] Failed to save:

Lukas, do you happen to have a machine where this is reproducible? Daniel mentioned he is unable to reproduce locally.

It got worse. Instead of 'Error: Name has already been taken' it fails at UI:

Oops, we're sorry but something went wrong undefined method `full_messages' for #<Array:0x0000000a9ec8c0>

2016-06-17 16:09:20 [app] [I] Started PUT "/wizard_states/14/steps/environment" for <CLIENT_IP> at 2016-06-17 16:09:20 +0200
2016-06-17 16:09:20 [app] [I] Processing by Containers::StepsController#update as HTML
2016-06-17 16:09:20 [app] [I]   Parameters: {"utf8"=>"✓", "authenticity_token"=>"TUbrIMms+pV+5xmXe4LzmWqGrkT295aq4BOETqbaX0U=", "docker_container_wizard_states_environment"=>{"tty"=>"1", "attach_stdin"=>"1", "attach_stdout"=>"1", "attach_stderr"=>"1"}, "button"=>"", "wizard_state_id"=>"14", "id"=>"environment"}
2016-06-17 16:09:26 [app] [W] Action failed
 | NoMethodError: undefined method `full_messages' for #<Array:0x0000000a9ec8c0>
 | /opt/theforeman/tfm/root/usr/share/gems/gems/foreman_docker-2.0.1.10/app/controllers/containers/steps_controller.rb:61:in `create_container'
 | /opt/theforeman/tfm/root/usr/share/gems/gems/foreman_docker-2.0.1.10/app/controllers/containers/steps_controller.rb:22:in `update'


Though this error a container is created (as show both UI and docker ps -a) 


While containers with names that are used for the 1st time are created successfully.

VERIFIED.

@satellite-6.2.0-19.1.el7sat.noarch
tfm-rubygem-foreman_docker-2.0.1.11-1.el7sat.noarch

used manual reproducer described in comment #0:

...
5. Create container named container1 once again

Container was created successfully

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2016:1501