Add Cloud Volume Type model

[mansam]

https://bugzilla.redhat.com/show_bug.cgi?id=1592900

Adds a basic model for Cloud Volume Types, which are needed for mapping new Cinder volumes to specific backends. This is especially important for Openstack V2V infrastructure mapping. Depends on the schema migration in ManageIQ/manageiq-schema#223

[mansam]

@roliveri This is Cinder-related, your feedback would be appreciated.

[roliveri]

I'm not sure I understand the need for a basic model for volume types. Can't volume types be represented as subclasses of a common base class, and queried accordingly?
It seems the data stored in this new table will not vary within type, so they can probably just be defined as class-specific values of the type subclasses.

[mansam]

Volume types are user defined, so I believe they would need to be collected from the Cinder API like any other inventory: https://developer.openstack.org/api-ref/block-storage/v3/index.html#volume-types-types

[roliveri]

@mansam
Ah, I see. It's a bit confusing because type is overloaded. There are types of volumes like: Cinder, EBS, etc. These are user-defined sub-types within type. Do you think it's worthwhile renaming these classes (and tables) to make this distinction more clear?

[mansam]

@roliveri Do you think calling this class/table "CloudVolumeBackingType" would avoid the possible confusion?

[roliveri]

@mansam I'm not sure. To me, backing type indicates the type of storage on which a virtual volume is based.

Are we really talking about sub-types or sub categories of a given storage type?

I'm not sure it's worth spending too much time on. Maybe a comment in the model class definition will be enough to clear up any confusion.

[mansam]

Cinder Volume Types are mostly a way to set the backend on which to create a volume, so using BackingType in the name probably isn't too confusing. But I agree with you that a comment is probably more than sufficient.

[miq-bot]

Checked commits mansam/manageiq@a71a1f6~...a204524 with ruby 2.3.3, rubocop 0.52.1, haml-lint 0.20.0, and yamllint 1.10.0
3 files checked, 3 offenses detected

app/models/cloud_volume_type.rb

• ❗ - Line 10, Col 3 - Rails/InverseOf - Specify an :inverse_of option.

app/models/manageiq/providers/cloud_manager.rb

• ❗ - Line 23, Col 5 - Rails/InverseOf - Specify an :inverse_of option.

app/models/manageiq/providers/storage_manager/block_mixin.rb

• ❗ - Line 8, Col 5 - Rails/InverseOf - Specify an :inverse_of option.

[aufi]

👍

[mansam]

ManageIQ/manageiq-schema#223 has been merged, so this can be merged.

[Ladas]

👍 looks good