PowerVM Driver Integration (Pike)

This blueprint continues the work begun in Ocata, integrating a
subset of the out-of-tree nova-powervm function into an in-tree driver.
This work is expected to continue over multiple subsequent releases.

Blueprint: powervm-nova-compute-driver
Previously-approved: Ocata

Change-Id: Idbec8ed2f47b25022163b2f0ddc408766ad37e76
This commit is contained in:
Eric Fried
2017-02-10 11:03:50 -06:00
committed by Matt Riedemann
parent e178c2bb59
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This work is licensed under a Creative Commons Attribution 3.0 Unported
License.
http://creativecommons.org/licenses/by/3.0/legalcode
====================================
PowerVM Driver Integration - Phase 2
====================================
`<https://blueprints.launchpad.net/nova/+spec/powervm-nova-compute-driver>`_
The PowerVM driver has been developed out-of-tree, but with the intention to
provide an in-tree implementation. Before it could be integrated in-tree, the
Nova core teams provided several requirements that have since been met. This
blueprint is the second in a series that will work toward PowerVM driver
integration in-tree.
Problem description
===================
The PowerVM driver, which provides OpenStack enablement for AIX, IBM i and
Linux virtual machines running on a PowerVM hypervisor, has been proposed for
integration into the main Nova tree. However, as the out-of-tree driver has
grown to contain a significant amount of function and maturity over the past
few OpenStack releases, the intention is to bring this driver in-tree. The
work to drive towards full integration is expected to be driven over multiple
OpenStack releases. The first blueprint provided integration of the
PowerVMLiveMigrateData object into Nova for the Ocata release, and laid out
plans to incorporate minimal compute driver functionality incrementally. This
blueprint continues that work.
The PowerVM driver team has met the following requirements from the Nova core
team.
* CI running and publishing results against Nova and nova-powervm driver:
Results are publicly available, as well as the configuration of the CI. Per
guidance from the Nova core team, the CI runs against all Nova change sets
but is not currently voting on patches as it is not an in-tree driver.
The `configuration for the CI`_ is also publicly available.
* External users beyond PowerVC:
Companies are actively using the PowerVM driver to integrate into OpenStack
clouds with Kolla and RDO. The PowerVM driver team also has added PowerVM to
the OpenStack-Ansible project and PowerVM is now a target platform for OSA.
* Show commitment to the driver:
Our first supported release was Liberty and we continue to maintain, grow and
extend the driver with each subsequent release, following the stable branch
support model. We are committed to developing the driver following the
`OpenStack way`_, with open source code, open design/development, and an
open community (IRC @ #openstack-powervm, etc). The PowerVM driver fits
the Nova compute driver design, and follows the community development
direction. We also ensure that the development team is actively
participating in upstream development - attending IRC meetings, mid-cycles,
and summits.
The out-of-tree driver will be maintained, supported and extended as the
in-tree driver is being integrated. For this phase, it is expected new code
will first be proposed to the out-of-tree driver and then proposed in-tree. As
the integration of the driver progresses further, that process shifts to all
code being proposed in-tree. However, for any contribution (either in-tree or
out-of-tree), the primary contributors of this blueprint will ensure the change
is proposed to the other driver during this transition period.
.. _`configuration for the CI`: https://github.com/powervm/powervm-ci
.. _`OpenStack way`: https://governance.openstack.org/reference/new-projects-requirements.html
Use Cases
---------
* A user should be able to deploy a glance-based image with basic networking on
a system with the PowerVM hypervisor. That image may be Linux (RHEL, SLES,
Ubuntu, etc...), AIX or IBM i.
Proposed change
===============
The change proposed is to submit a series of patches building out enough basic
function to support deployment of a glance-based virtual machine on PowerVM.
This subset of the driver code (and associated unit tests) would support
features such as:
* Basic VM lifecycle tasks (spawn, shutdown, reboot, snapshot, etc)
* Instance status
* VNC console
* Flat/VLAN networking using the Open vSwitch Neutron agent
* Config drive
* Boot disk via host localdisk or Shared Storage Pool Logical Unit (PowerVM
clustered file system).
This phase of the driver is meant to get the net minimum of `mandatory` and
`choice` options from the `support matrix`_.
.. _`support matrix`: http://docs.openstack.org/developer/nova/support-matrix.html
We see this as a long-term journey. We will continue to work to bring further
function into the Nova tree over subsequent releases.
Some of the specific functions that would come as part of future blueprints
that are not part of this one:
* Resize
* Live Migrate
* Cold Migrate
* Cinder Volume Support
* Shared Ethernet Support (PowerVM network technology)
* SR-IOV Support
There are additional functions (that are currently integrated in the
out-of-tree driver), but they will be proposed as part of subsequent
blueprints.
Alternatives
------------
1) Integrate the entire driver. That would be too unwieldy to do in one
release and would require too much core reviewer time.
2) Do not integrate the driver. As there are users of the driver, and the Nova
direction is to have drivers in-tree, this is not an option.
Data model impact
-----------------
None
REST API impact
---------------
None
Security impact
---------------
None
Notifications impact
--------------------
None
Other end user impact
---------------------
None
Performance Impact
------------------
None. Integration has no performance effect on existing code paths.
Other deployer impact
---------------------
Deployers who wish to use the PowerVM driver will need to change the
``compute_driver`` in their conf to ``powervm.PowerVMDriver``. The in-tree
PowerVM driver will initially have a very limited set of functionality. As
noted above, they can install the nova-powervm out-of-tree driver to gain the
additional functionality while the team works over multiple releases to
integrate the driver.
For this first integration, there will be no required configuration from the
deployer beyond setting the ``compute_driver`` type. The driver will be
documented in the hypervisor support matrix (along with its capabilities
in-tree).
A new dependency on ``pypowervm`` was introduced in Ocata. This is a
third-party, open-source library that allows its consumers to drive PowerVM
virtualization. In pike, the pypowervm version requirement will be updated as
necessary to accomodate driver function.
Developer impact
----------------
There are no changes to the driver API. The PowerVM driver will conform to the
existing Nova API.
Implementation
==============
Assignee(s)
-----------
Primary assignees:
efried
esberglu
thorst
Other contributors:
wangqinw
adreznec
Work Items
----------
* Add support for basic life cycle tasks (Create, Power On/Off, Delete)
* Add support for OVS-based networks
* Add console support via VNC
* Increase the scope of the existing PowerVM CI to include the PowerVM driver
in-tree. Two jobs will need to be kicked off for each Nova change (one
for out-of-tree, one for in-tree) during this transition period.
Dependencies
============
* `pypowervm`_ - third-party, open-source library that allows for control of
the PowerVM platform.
* PowerVM with `NovaLink`_ - PowerVM is the hypervisor, and the NovaLink is a
Linux based Virtualization Management VM. The Novalink virtualization
management VM is what allows the nova-compute process to run on the system
itself.
.. _`pypowervm`: http://github.com/powervm/pypowervm
.. _`NovaLink`: http://www-01.ibm.com/common/ssi/cgi-bin/ssialias?subtype=ca&infotype=an&supplier=897&letternum=ENUS215-262
Testing
=======
All code paths run through the standard Tempest tests as part of our CI. The
code will also include significant unit test. This code will come from the
out-of-tree nova-powervm driver. The CI infrastructure will also continue to
support the automated testing of the out-of-tree nova-powervm driver.
Voting will be enabled for the CI for the in-tree driver only. Per our
discussions with the Nova core team, we will not enable voting for the
out-of-tree driver. However, logs for both runs are publicly available, and we
have dedicated team members monitoring and supporting the CI.
No new tests are required. The PowerVM driver is meant to conform to the
Nova model.
Outside testing will be done to validate performance and scale. This has
already been done on the out-of-tree driver. RefStack compliance will also be
validated, but we do not expect this first phase to pass as it does not have
all of the required support out of the box.
Documentation Impact
====================
We will work with the ID team to create new documents on the PowerVM driver.
A proposed update to the hypervisor driver matrix will be made as well.
References
==========
* nova-powervm:
* Overview: Out-of-tree Nova driver for PowerVM
* Source: `<git://git.openstack.org/openstack/nova-powervm/>`_
* Bugs: `<https://bugs.launchpad.net/nova-powervm/>`_
* pypowervm
* Overview: third-party, open-source module providing access to PowerVM
hypervisor functionality.
* Source: `<https://github.com/powervm/pypowervm/tree/develop>`_
* Bugs: `<https://bugs.launchpad.net/pypowervm/>`_
* networking-powervm:
* Overview: Neutron ML2 mechanism driver and plugin supporting PowerVM's
Shared Ethernet Adapter and (as of newton) SR-IOV virtual NIC.
* Source: `<git://git.openstack.org/openstack/networking-powervm/>`_
* Bugs: `<https://bugs.launchpad.net/networking-powervm/>`_
* ceilometer-powervm:
* Overview: Ceilometer collector for the PowerVM platform. Captures I/O,
CPU and memory statistics.
* Source: `<git://git.openstack.org/openstack/ceilometer-powervm/>`_
* Bugs: `<https://bugs.launchpad.net/ceilometer-powervm/>`_
* Continuous Integration:
* Overview: The CI server's configuration
* Tempest Configuration: `<https://github.com/powervm/powervm-ci/blob/master/tempest/tempest.conf>`_
History
=======
Historically speaking, there have been a couple of other Power drivers. The
first PowerVM driver was built on PowerVM and only worked with a component
called IVM. The challenge with this was that it required the nova-compute to
run on a separate server and SSH in to issue commands. It also did not
integrate well with other OpenStack components.
There was also the PowerVC OpenStack driver. This sat on top of PowerVC and
was a clustered management model. Due to the push away from clustered
management, this was not the approved management model for OpenStack Nova
Compute. It was never pulled in-tree.
This model is different, with core changes to the PowerVM hypervisor. It has
been shipping in the field for a long period of time, and has products built on
top of it. It also matches the development model of OpenStack Nova and has
dedicated developers who have been working on it for multiple years.
Lastly, Power systems also natively run Linux. For those wishing to use KVM on
Power, the standard libvirt driver is also available. However, that support is
limited to Linux based client virtual machines.
A rough timeline is provided below.
* November 2013: PowerVM IVM driver removed due to lack of CI and development.
Also did not fit the direction of Nova core team to have the Nova compute
process running on the system itself.
* October 2014: `First commit`_ for new PowerVM driver built on NovaLink.
* May 2015: Socialized the NovaLink based PowerVM driver at the summit.
NovaLink changes the hypervisor itself to match the OpenStack model. All
OpenStack code was developed from the start as open source.
* October 2015: Liberty based out-of-tree nova-powervm driver released.
All developed openly. Support for:
* Lifecycle operations
* Spawn from glance
* Cinder FC support
* Nova with networking-powervm agent
* Live Migration
* AIX and Linux VMs
* DevStack
* TaskFlow in its core to support graceful rollbacks of failed operations
* January 2016: Continuous Integration environment live.
* April 2016: nova-powervm driver updated for Mitaka release.
All nova-powervm development done openly during the release. Initial
third-party contributions made.
Added new capabilities:
* Cold Migration / Rebuild / Resize
* Scalability testing
* Basic VNC Console
* IBM i VMs
* Scale & Resiliency testing
* July 2016: CI running against all Nova patch sets. Not voting (due to
Nova core team guidance) but logs still published to log server.
* October 2016: nova-powervm driver updated for Newton release. Updated for:
* SR-IOV via PowerVM vNIC
* Linux Bridge / OVS
* Enhancements to VNC console
* Integration with OpenStack Ansible (outside nova-powervm)
* October 2016: `First in-tree change set`_ proposed for compute driver
spawn/destroy.
* November 2016: PowerVMLiveMigrateData object introduced in-tree (Ocata).
* January 2017: pypowervm dependency introduced in requirements project
(Ocata).
.. _`First commit`: https://github.com/openstack/nova-powervm/commit/095e1c183baf4f9083d6b0d363818be21f64f992
.. _`First in-tree change set`: https://review.openstack.org/#/c/391288/
.. list-table:: Revisions
:header-rows: 1
* - Release Name
- Description
* - Ocata
- Introduced
* - Pike
- Re-proposed