Glance based cinder volume protection plugin

https://blueprints.launchpad.net/karbor/+spec/backup-volume-data-to-bank

Problem description

Currently, karbor support using cinder backup, cinder snapshot and freezer plugins to do cinder volume backup. These plugins all store the backup metadata to the bank but not the volume backup data.

In the use case of cross site, we need to do cinder volume backup and restore cross different sites (with different cinder/nova/glance service endpoints), this requires karbor to save the volume data in an independent storage media (bank), so that we can do backup in one site and do restore in another site that the two sites use the same volume backup data in one bank.

Obviously the cinder volume protection plugins in karbor can not satisfy the cross site needs now. So we should introduce a new volume protection plugin which can save volume data to karbor’s bank, like image protection plugin. Backup cinder volume through glance may be a valid choice.

Use Cases

As explained, users who want to do cross site backup and restore of cinder volumes.

Proposed change

Volume glance protection plugin

Add a new volume protection plugin which do the backup and restore of cinder volumes by glance service. Volume data would be stored in the bank as chunks like what image protection plugin do.

Steps of protect operation: 1. Create a temporary snapshot to the volume you want to backup 2. Create a temporary volume based on the snapshot in step 1 3. Create a temporary glance image of the temporary volume 4. Download the temporary image and save it to karbor bank 5. Clean all the temporary resources in step 1 to 4 6. Save the backup metadata to bank

Steps of restore operation: 1. Create an image with the volume data in bank 2. Create a volume with the created image in step 1 3. Wait for the volume status being available 4. Clean the created image in step 1

Steps in delete operation: 1. List and delete the objects (volume data and metadata) in bank.

Volume glance protection plugin schema:

OPTIONS_SCHEMA = {
    "title": "Volume Glance Protection Options",
    "type": "object",
    "properties": {
        "backup_name": {
            "type": "string",
            "title": "Backup Name",
            "description": "The name of the backup.",
            "default": None
        },
        "description": {
            "type": "string",
            "title": "Description",
            "description": "The description of the backup."
        }
    },
    "required": ["backup_name"]
}

RESTORE_SCHEMA = {
    "title": "Volume Glance Protection Restore",
    "type": "object",
    "properties": {
        "restore_name": {
            "type": "string",
            "title": "Restore Resource Name",
            "description": "The name of the restore resource ",
            "default": None
        },
    },
    "required": ["restore_name"]
}

Alternatives

None

Data model impact

None.

REST API impact

None

Security impact

None

Notifications impact

None

Other end user impact

None

Performance Impact

This plugin may be slower than cinder backup and cinder snapshot plugin.

Other deployer impact

Add the volume by glance protection plugin endpoint to setup.cfg. Add the volume by glance protection plugin configuration to provider file.

Developer impact

None

Implementation

Assignee(s)

Primary assignee: Pengju Jiao <jiaopengju@cmss.chinamobile.com>

Work Items

• Write volume by glance protection plugin

• Write tests

Dependencies

None

Testing

Unit tests in Karbor.

Documentation Impact

Add a usage example about volume by glance protection.

References

None