bareon-specs/specs/policy-based-partitioning.rst

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Policy-based partitioning

https://blueprints.launchpad.net/bareon/+spec/policy-based-partitioning

Problem description

We need the ability to verify the disposition of existing partitions during deployment. Bareon agent should support the prevention of modification of existing partitions during deployment when requested by the user or administrator.

Proposed change

NOTE: This change is added with a standalone "Ironic" data driver.

NOTE: This is a contribution of the feature developed within Cray OpenStack project. We will try to make a minimum changes to existing code.

We introduce the new attribute in provision.json, called partitions_policy. This policy will control the way of how partitions are applied. The partitions_policy, working together with “keep_data” attribute of partition/lv will control the data retention. The policy can be either:

• verify

  • Do verification: Compare partitions schema with existing partitions on the disk(disks). If there is an additional disk, not mentioned in schema (unknown) - it is ignored.
  • Do partitioning: partitions which do not have “keep_data” attribute are left as is (keep_data attribute is true by default); partitions which have “keep_data”:false attribute in schema are wiped;

• clean

  Ignore existing partitions on the disk(disks). Clean the disk and create partitions according to the schema. If there is an additional disk, not mentioned in schema (unknown) - it is ignored.

For example:

{
  "partitions_policy": "<verify|clean>",
  "partitions": [{
         "type":"disk",
         "id": ...,
         "volumes":[
            {
               "type":"partition",
               "id": …,
                # "keep_data": true - by default
            },
            {
               "id": …,
               "keep_data": false, # this partition will be wiped
               # (explicitly specified keep_data false here)
            },
          ],
}

Alternatives

There's already a keep_data flag in Nailgun driver, however it is impossible to verify HW partitions. So no alternatives to the current proposal.

Implementation

Assignee(s)

• max_lobur

Milestones

See blueprint ref above.

Work Items

• Rebase onto Bareon master

Dependencies

The code of this feature is on top of the following patches:

• rsync image deployment
• functional tests

thus needs to be prosed after these.