Support add tags for instances when booting

https://blueprints.launchpad.net/nova/+spec/support-tag-instance-when-boot

This blueprint proposed to add support adding tags for instances when booting.

Problem description

Tags for servers are supported in microversion 2.26, but currently we can only add tags to instances that are already existed in the cloud, that is, we can not set tags to instances when we boot the instances. User will have to first find the instances and then add tags with another API call. This is not user-friendly enough when user doing bulk boot, it will be not practical to add tags for those instances one by one afterwards.

Use Cases

As an user, I would like to add tags to my instances when I boot them, especially when I doing bulk boot, I may want to add some tags for the instances created by this call.

Proposed change

Add a new microversion to Servers create API to support adding tags when booting instances. The number of tags can be added will be limited by instance.MAX_TAG_COUNT just as what server-tags API does.

Alternatives

Keep the current implementation.

Data model impact

A new column tags will be added to the build_requests table. The size of the column will be at least 3200, which is the length of a serialized list made of 50 tags (limit per instance) where each tag length is 60 (size limit per tag).

REST API impact

  • URL:
    • /v2.1/servers:

  • Request method:
    • POST

The tags data will be able to add as optional parameter to request payload

{
    ...
    'tags': ['foo', 'bar', 'baz']
    ...
}

The length of each tag will be limited to 60, which is the same as the current limit of the tags length in the server-tags API. [1]

The tags field is already included in the GET /servers/{server_id} response after microversion 2.26. [2]

Security impact

None

Notifications impact

Tags will be included in instance.create versioned notification [3].

Other end user impact

User will be able to set tags when boot instances using specific microversion. python-novaclient will also make modifications to support this feature.

Performance Impact

None

Other deployer impact

None

Developer impact

None

Implementation

Assignee(s)

Primary assignee:

Zhenyu Zheng

Work Items

  • Add tag instances support when booting

  • Add related tests

Dependencies

None

Testing

  • Add related unittest

  • Add related functional test

  • Add related tempest test

Documentation Impact

Add docs that mention the tags can be added when boot instances after the microversion.

History

Revisions

Release Name

Description

Ocata

Introduced

Pike

Re-proposed