openstack
/
ironic-specs
Code Issues Proposed changes

Amend future of classic drivers with automated migration 

It was requested by operators on the Forum that we provide at least
some migration between classic drivers and hardware types.

This change proposes using the "online_data_migration" command
to migrate existing nodes.

Change-Id: I647b4011bbbfd92cd2e4007792bd03d7ba88bc39
This commit is contained in:
Dmitry Tantsur 2017-12-15 16:31:58 +01:00
parent ca5f9d4e84
commit d7532ca028
1 changed files with 79 additions and 0 deletions
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79
specs/approved/classic-drivers-future.rst
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@ -98,6 +98,16 @@ In the Queens cycle we will deprecate classic drivers.
the driver-specific documentation and the upgrade documentation bit explained
above.
* Provide automatic migration to hardware types as part of the
``online_data_migration`` command - see `Automatic migration`_.
.. note::
We decided to not provide any automatic migration on the API level in the
node create and update API. Doing so would require us to maintain mapping
between classic drivers and corresponding hardware types/interfaces
foreever. It also may be confusing for operators, if, for example, the
result of the node creation request differs from the outcome.
**Rocky**
In the Rocky release the support for classic drivers is removed.
@ -116,6 +126,74 @@ In the Rocky release the support for classic drivers is removed.
* Update the driver listing API to always return an empty result when
``classic`` type is requested.
Automatic migration
-------------------
To simplify transition for operators, make ``online_data_migration`` in the
Queens release automatically update nodes.
* Extend BaseDriver_ with a new class method:
.. code-block:: python
@classmethod
def to_hardware_type(cls, node):
"""Return corresponding hardware type and hardware interfaces.
:param cls: the driver class
:param node: node record from the database
:returns: dictionary containing node fields to update: ``driver`` and
all interface fields (except for ``network`` and ``storage`` which
have always been dynamic, even for nodes with a classic driver).
"""
For example, for the ``agent_ipmitool`` driver:
.. code-block:: python
@classmethod
def to_hardware_type(cls, node):
if CONF.inspector.enabled:
inspect_interface = 'inspector'
else:
inspect_interface = 'no-inspect'
return {'driver': 'ipmi',
'boot_interface': 'pxe',
'console_interface': 'no-console',
'deploy_interface': 'direct',
'inspect_interface': inspect_interface,
'management_interface': 'ipmitool',
'power_interface': 'ipmitool',
'raid_interface': 'agent',
'vendor_interface': 'no-vendor'}
* Update the ``online_data_migration`` command with a new migration:
#. Load classes for all classic drivers in the ``ironic.drivers`` entrypoint
(but do not instantiate them).
#. For each node using a classic driver:
#. Calculate required changes using ``DriverClass.to_hardware_type``.
#. If the hardware type or any interface is not in the enabled list
(``enabled_hardware_types`` or ``enabled_***_interfaces``), issue
a warning and skip the node.
.. note::
Due to idempotency of the migrations, operators will be able to
re-run this command after fixing the warnings to update the
skipped nodes.
#. Update the node record in the database.
* In the **Rocky** cycle, update the ``dbsync`` command with a check that no
nodes are using classic drivers. As the list of classic drivers will not be
available at that time (they will be removed from the tree), maintain the
list of classic driver names that used to be in tree and check nodes against
this list. Remove this check in the release after Rocky.
Alternatives
------------
@ -266,3 +344,4 @@ References
==========
.. _driver_factory.py: https://git.openstack.org/cgit/openstack/ironic/tree/ironic/common/driver_factory.py
.. _BaseDriver: https://docs.openstack.org/ironic/latest/contributor/api/ironic.drivers.base.html#ironic.drivers.base.BaseDriver