Execution of a command in a container from system tests 'dockerctl shell <cotainer> <command>' hungs waiting for input

[Dennis Dmitriev]

When 'dockerctl shell <cotainer> <command>' is executed from system tests, 'dockerctl' hungs waiting for input or a signal:
http://paste.openstack.org/show/193326/

If attach to the process with 'strace', dockerctl exit:
http://paste.openstack.org/show/193328/

If in system tests add 'echo "" | dockerctl shell <cotainer> <command>', then the command executes fine from system tests.

It is not reproduced manually, but constantly reproduced in system tests with latest ISO:
api: '1.0'
astute_sha: 3e43895621370e65737b240e999f6c7391e68352
auth_required: true
build_id: 2015-03-18_22-54-44
build_number: '206'
feature_groups:
- mirantis
fuellib_sha: de7ea04ef1a8b8399949d1ad28c6ac29d2b3e084
fuelmain_sha: fbfe367850a7e902d67d5ba05bfb9ed937a38dae
nailgun_sha: ff2e37abf5801757bd20b80a7d2d41df2e08ed63
ostf_sha: 9435ec9f0aaf5bb8b9773347af871ab281b9ae78
production: docker
python-fuelclient_sha: 14f2b3e0c9fd1580d85a83b7eea95fbe893665ac
release: '6.1'
release_versions:
  2014.2-6.1:
    VERSION:
      api: '1.0'
      astute_sha: 3e43895621370e65737b240e999f6c7391e68352
      build_id: 2015-03-18_22-54-44
      build_number: '206'
      feature_groups:
      - mirantis
      fuellib_sha: de7ea04ef1a8b8399949d1ad28c6ac29d2b3e084
      fuelmain_sha: fbfe367850a7e902d67d5ba05bfb9ed937a38dae
      nailgun_sha: ff2e37abf5801757bd20b80a7d2d41df2e08ed63
      ostf_sha: 9435ec9f0aaf5bb8b9773347af871ab281b9ae78
      production: docker
      python-fuelclient_sha: 14f2b3e0c9fd1580d85a83b7eea95fbe893665ac
      release: '6.1'

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/165668

[OpenStack Infra (hudson-openstack)]

Change abandoned by Dennis Dmitriev (<email address hidden>) on branch: master
Review: https://review.openstack.org/165668
Reason: https://review.openstack.org/#/c/163921/ already covered the problem.

[Bogdan Dobrelya (bogdando)]

Please specify how the issue was covered?