5016627f04
Spec repos do not have code to unit test. The gate job definition for the py27 and py35 jobs skip if there doc only changes, which is all we will ever have in the specs repo. Therefore the one "test" we had will never be run. We were using this unit test as a check for formatting issues with the rst files. This was done before doc8 was available. Now that we can use doc8, we should just switch to running that as part of the pep8 jobs. Also fixes all the errors caught by doc8 that were not caught by our unit test check. Change-Id: Ida20764edde3a07c89703d82b41958c96548b239
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This work is licensed under a Creative Commons Attribution 3.0 Unported
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License.
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http://creativecommons.org/licenses/by/3.0/legalcode
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=====================================
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Add support for chiscsi iscsi helper
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=====================================
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https://blueprints.launchpad.net/cinder/+spec/chiscsi-iscsi-helper
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The Chelsio iSCSI target(chiscsi) serves as a drop in replacement for the IET
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target, aiming to provide the same functionality as IET. This spec aims at
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adding support for said target implementation as a pure iscsi_helper.
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chiscsi supports offloading of iSCSI PDU's when required hardware (supported
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Chelsio Network cards) is available but will work on any regular NIC as well.
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Offloading or lack thereof requires no user intervention once target drivers
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are installed. Implementation is initiator agnostic as well, no changes needed
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on initiator side.
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Problem description
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===================
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chiscsi target is not currently supported by openstack
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* For a Deployer trying to use offloaded iSCSI support on target side, no
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option is currently available.
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* Manual intervention is currently required to export volumes, as cinder does
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not understand chiscsi target implementation.
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Use Cases
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=========
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Proposed change
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===============
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Add one more iscsi_helper option to cover chiscsi, the driver for this will
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interact with the chiscsi target implementation to provide same functionality
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as iet.
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Use of offloading is dependent on required hardware being present but is
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completely optional. No intervention is required to enable offload and
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offloading will happen in a manner completely transparent to initiator side.
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No initiator side changes are required to make use of chiscsi, with or without
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offload support. No extra configuration options are required.
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Alternatives
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------------
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None
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Data model impact
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-----------------
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None
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REST API impact
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---------------
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None
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Security impact
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---------------
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None
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Notifications impact
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--------------------
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None
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Other end user impact
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---------------------
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None
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Performance Impact
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------------------
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If iSCSI offload is available, there is a significant performance boost to be
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gained. If offloading is not used, performance and resource usage would be
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roughly on par with IET or better.
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Other deployer impact
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---------------------
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* No new config options are required besides an extra allowed value for
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'iscsi_helper' that would need to be explicitly set to 'chiscsi'.
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* chiscsi target needs to be installed before it can be used.
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Developer impact
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----------------
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None
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Implementation
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==============
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Assignee(s)
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-----------
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Primary assignee:
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anish7
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Other contributors:
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kxie
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Work Items
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----------
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Using iet helper as base, create iscsi_helper for chiscsi, with equivalent
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commands for all required apis
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Dependencies
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============
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* Ability to use chiscsi target obviously depends on target driver being
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installed, and command utility available on path. No other dependencies
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Testing
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=======
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Current test for IET target should work just fine for chiscsi
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Documentation Impact
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====================
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None except listing chiscsi as an available iscsi_helper
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References
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==========
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* http://www.chelsio.com/iscsi-target-software/
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