Problem attaching iSCSI volumes without TCP transport

[Hamdy Khader]

Problem:
OS-Brick doesn't recognise transport type from command "iscsiadm -m session" other than TCP,
for example if [cinder.conf]iscsi_ptotocol=iser, OS-Brick will not be able to see the created
iscsi sessions and will always try to log into iscsi, at that point iscsi already has session
open so each login attempt will be rejected and volume will be in Attaching status.

$iscsiadm -m session
iser: [9] 1.1.1.1:3260,1 iqn.2010-10.org.openstack:volume-38b2e6bb-30e1-46c1-b02f-102b129e3be3 (non-flash)

Reproduce:
1. create VM that uses image as volume source.
2. change iscsi_ptotocol to iser in /cinder.conf
3. create volume
5. attach it to the VM

Cinder log:
Aug 14 04:06:47 hamdyk-X9DRFR nova-compute[16882]: DEBUG oslo.privsep.daemon [-] privsep: request[140297724561200]: (3, 'os_brick.privileged.rootwrap.execute_root', ('iscsiadm', '-m', 'session'), {'check_exit_code': (0, 1, 21, 255)}) {{(pid=18057) loop /usr/local/lib/python2.7/dist-packages/oslo_privsep/daemon.py:443}}
Aug 14 04:06:47 hamdyk-X9DRFR nova-compute[16882]: DEBUG oslo_concurrency.processutils [-] Running cmd (subprocess): iscsiadm -m session {{(pid=18057) execute /usr/local/lib/python2.7/dist-packages/oslo_concurrency/processutils.py:355}}
Aug 14 04:06:47 hamdyk-X9DRFR nova-compute[16882]: DEBUG oslo_concurrency.processutils [-] CMD "iscsiadm -m session" returned: 0 in 0.006s {{(pid=18057) execute /usr/local/lib/python2.7/dist-packages/oslo_concurrency/processutils.py:385}}
Aug 14 04:06:47 hamdyk-X9DRFR nova-compute[16882]: DEBUG os_brick.initiator.connectors.iscsi [None req-35a4bf00-7056-457a-8371-e6dc9024165e admin admin] iscsiadm ('-m', 'session'): stdout=iser: [9] 1.1.1.1:3260,1 iqn.2010-10.org.openstack:volume-38b2e6bb-30e1-46c1-b02f-102b129e3be3 (non-flash)
Aug 14 04:06:47 hamdyk-X9DRFR nova-compute[16882]: stderr= {{(pid=16882) _run_iscsiadm_bare /usr/local/lib/python2.7/dist-packages/os_brick/initiator/connectors/iscsi.py:1077}}
Aug 14 04:06:47 hamdyk-X9DRFR nova-compute[16882]: DEBUG oslo.privsep.daemon [-] privsep: request[140297724561200]: (3, 'os_brick.privileged.rootwrap.execute_root', ('iscsiadm', '-m', 'node', '-T', u'iqn.2010-10.org.openstack:volume-38b2e6bb-30e1-46c1-b02f-102b129e3be3', '-p', u'1.1.1.1:3260', '--login'), {'attempts': 1, 'check_exit_code': (0, 15, 255), 'delay_on_retry': True}) {{(pid=18057) loop /usr/local/lib/python2.7/dist-packages/oslo_privsep/daemon.py:443}}
Aug 14 04:06:47 hamdyk-X9DRFR nova-compute[16882]: DEBUG oslo_concurrency.processutils [-] Running cmd (subprocess): iscsiadm -m node -T iqn.2010-10.org.openstack:volume-38b2e6bb-30e1-46c1-b02f-102b129e3be3 -p 1.1.1.1:3260 --login {{(pid=18057) execute /usr/local/lib/python2.7/dist-packages/oslo_concurrency/processutils.py:355}}
Aug 14 04:06:47 hamdyk-X9DRFR nova-compute[16882]: DEBUG oslo_concurrency.processutils [-] CMD "iscsiadm -m node -T iqn.2010-10.org.openstack:volume-38b2e6bb-30e1-46c1-b02f-102b129e3be3 -p 1.1.1.1:3260 --login" returned: 15 in 0.005s {{(pid=18057) execute /usr/local/lib/python2.7/dist-packages/oslo_concurrency/processutils.py:385}}
Aug 14 04:06:47 hamdyk-X9DRFR nova-compute[16882]: DEBUG oslo.privsep.daemon [-] privsep: reply[140297724561200]: (4, ('', 'iscsiadm: iser: 1 session requested, but 1 already present.\niscsiadm: Could not log into all portals\n')) {{(pid=18057) loop /usr/local/lib/python2.7/dist-packages/oslo_privsep/daemon.py:456}}
Aug 14 04:06:47 hamdyk-X9DRFR nova-compute[16882]: DEBUG os_brick.initiator.connectors.iscsi [None req-35a4bf00-7056-457a-8371-e6dc9024165e admin admin] iscsiadm ('--login',): stdout= stderr=iscsiadm: iser: 1 session requested, but 1 already present.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/pike
Review: https://review.openstack.org/496737

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/493568
Committed: https://git.openstack.org/cgit/openstack/os-brick/commit/?id=af2f60f9bab271ba26d4d1e8f15e0d1ce7f1ccec
Submitter: Jenkins
Branch: master

commit af2f60f9bab271ba26d4d1e8f15e0d1ce7f1ccec
Author: Aviram Bar-Haim <email address hidden>
Date: Mon Aug 14 16:50:39 2017 +0300

    Fix iSCSI volume attachment over RDMA transport

    Recent changes assumed 'tcp:' prefix to iscsi sessions,
    and that broke the session status discovery for RDMA
    connections. in this change we add the 'iser:' transport
    prefix to the os-brick functions, to fix volumes attach
    over RDMA.

    Closes-bug: #1710599
    Change-Id: I27b30dafcf488ebd125917e1924c828e3bdf3a99

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/496737
Committed: https://git.openstack.org/cgit/openstack/os-brick/commit/?id=f1a8346a51836cea43943ad47d65fa8e72fbfc24
Submitter: Jenkins
Branch: stable/pike

commit f1a8346a51836cea43943ad47d65fa8e72fbfc24
Author: Aviram Bar-Haim <email address hidden>
Date: Mon Aug 14 16:50:39 2017 +0300

    Fix iSCSI volume attachment over RDMA transport

    Recent changes assumed 'tcp:' prefix to iscsi sessions,
    and that broke the session status discovery for RDMA
    connections. in this change we add the 'iser:' transport
    prefix to the os-brick functions, to fix volumes attach
    over RDMA.

    Closes-bug: #1710599
    Change-Id: I27b30dafcf488ebd125917e1924c828e3bdf3a99
    (cherry picked from commit af2f60f9bab271ba26d4d1e8f15e0d1ce7f1ccec)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/os-brick 1.15.3 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/os-brick 2.0.0 release.