mogan-specs/specs/ocata/approved/lock-instance-api.rst

Add lock API for changing instance to lock/unlock

https://blueprints.launchpad.net/mogan/+spec/lock-instances

This spec proposes to provide the lock REST API, then operators do not have to worry about instances could be terminated by mistaken.

Problem description

In Mogan, we provided REST API to delete baremetal servers when do not need any more. However, there is no limit of delete REST API usage. So user can delete baremetal server in any circumstances. This change proposes to add the lock REST API to disable terminate baremetal server if necessary.

Use Cases

when booting a baremetal server, a delete request from other users by mistaken is unacceptable. To avoid this, lock your server is better.

For another use case, when maintaining, delete maintained baremetal servers is also unacceptable. As an operator, if you want to maintain a baremetal servers, You could lock baremetal servers to forbid deleting operations. After maintaining, you need to unlock baremetal servers. Then you can do other operations.

Proposed change

• Modify the data model to record the lock state of instances.
• Add the lock REST API to lock/unlock instance.

Alternatives

Maybe leveraging the instance state instead of adding a new locked field is an alternative. While, if we want to lock an buiding instance, it`s difficult to deal with the lock state and build state with only one state column.

Data model impact

The mogan.objects.instance.Instance object would have new locked and locked_by field of type mogan.objects.fields.ListOfStrings that would be populated on-demand(i.e. not eager-loaded).

A locked shall be defined as a tinyint no longer than 1 bytes in length, and the locked_by shall be defined as an enum with owner and admin as its valid values.

For the database schema, the following table changes would suffice :

ALTER TABLE `instances`
ADD COLUMN `locked`  tinyint(1) NULL DEFAULT NULL,
ADD COLUMN `locked_by`  enum('owner','admin') NULL DEFAULT NULL;

REST API impact

• Request method:

  • PUT

• URL:

  • /instances/{instance_uuid}/lock

Lock an instance

• Parameters for request :

  {
      "target": true
  }

Unlock an instance

• Parameters for request :

  {
      "target": false
  }

• Normal HTTP response code:

  • 202 ACCEPTED

• Expected error http response codes

  • 400 BadRequest The request params were invalied
  • 404 NotFound The instance requested to be lock was not found
  • 403 Forbidden The user has no access to request this API
  • 409 Conflict The instance requested to be lock or unlock was not in valid status

• Policy changes:

  Only Admin and owner is allowed to request these API.

  • If Admin locked an instance, only Admin can unlock it.
  • If Owner locked an instance, both Owner and Admin can unlock it.
  • If an instance has been locked, UNLOCK was only allowed for Owner and Admin. And, other operations should be denied for non-admin.

Security impact

None

Notifications impact

None

Other end user impact

As part of this effort we will also need to add the support to python-moganclient.

Performance Impact

None

Other deployer impact

None

Developer impact

None

Implementation

Assignee(s)

Primary assignee:

zhangjialong <zhangjl@awcloud.com>

Other contributors:

jolie <guoshan@awcloud.com>

Work Items

• Modify the database model of instances.
• Add lock REST API to lock and unlock instances.
• Valid an instance is locked before execute other operations.
• Support the new lock REST API in python-moganclient.

Dependencies

None.

Testing

• Unit tests will be added to Mogan for testing the new REST API.

Documentation Impact

The in-tree API reference will be updated for the mogan REST API documentation.

References

None