## Changes
This PR:
1. Incrementally improves the error messages shown to the user when the
volume they are referring to in `workspace.artifact_path` does not
exist.
2. Performs this validation in both `bundle validate` and `bundle
deploy` compared to before on just deployments.
3. It runs "fast" validations on `bundle deploy`, which earlier were
only run on `bundle validate`.
## Tests
Unit tests and manually. Also, existing integration tests provide
coverage (`TestUploadArtifactToVolumeNotYetDeployed`,
`TestUploadArtifactFileToVolumeThatDoesNotExist`)
Examples:
```
.venv➜ bundle-playground git:(master) ✗ cli bundle validate
Error: cannot access volume capital.whatever.my_volume: User does not have READ VOLUME on Volume 'capital.whatever.my_volume'.
at workspace.artifact_path
in databricks.yml:7:18
```
and
```
.venv➜ bundle-playground git:(master) ✗ cli bundle validate
Error: volume capital.whatever.foobar does not exist
at workspace.artifact_path
resources.volumes.foo
in databricks.yml:7:18
databricks.yml:12:7
You are using a volume in your artifact_path that is managed by
this bundle but which has not been deployed yet. Please first deploy
the volume using 'bundle deploy' and then switch over to using it in
the artifact_path.
```
## Changes
This PR adds support for UC volumes to DABs.
### Can I use a UC volume managed by DABs in `artifact_path`?
Yes, but we require the volume to exist before being referenced in
`artifact_path`. Otherwise you'll see an error that the volume does not
exist. For this case, this PR also adds a warning if we detect that the
UC volume is defined in the DAB itself, which informs the user to deploy
the UC volume in a separate deployment first before using it in
`artifact_path`.
We cannot create the UC volume and then upload the artifacts to it in
the same `bundle deploy` because `bundle deploy` always uploads the
artifacts to `artifact_path` before materializing any resources defined
in the bundle. Supporting this in a single deployment requires us to
migrate away from our dependency on the Databricks Terraform provider to
manage the CRUD lifecycle of DABs resources.
### Why do we not support `preset.name_prefix` for UC volumes?
UC volumes will not have a `dev_shreyas_goenka` prefix added in `mode:
development`. Configuring `presets.name_prefix` will be a no-op for UC
volumes. We have decided not to support prefixing for UC resources. This
is because:
1. UC provides its own namespace hierarchy that is independent of DABs.
2. Users can always manually use `${workspace.current_user.short_name}`
to configure the prefixes manually.
Customers often manually set up a UC hierarchy for dev and prod,
including a schema or catalog per developer. Thus, it's often
unnecessary for us to add prefixing in `mode: development` by default
for UC resources.
In retrospect, supporting prefixing for UC schemas and registered models
was a mistake and will be removed in a future release of DABs.
## Tests
Unit, integration test, and manually.
### Manual Testing cases:
1. UC volume does not exist:
```
➜ bundle-playground git:(master) ✗ cli bundle deploy
Error: failed to fetch metadata for the UC volume /Volumes/main/caps/my_volume that is configured in the artifact_path: Not Found
```
2. UC Volume does not exist, but is defined in the DAB
```
➜ bundle-playground git:(master) ✗ cli bundle deploy
Error: failed to fetch metadata for the UC volume /Volumes/main/caps/managed_by_dab that is configured in the artifact_path: Not Found
Warning: You might be using a UC volume in your artifact_path that is managed by this bundle but which has not been deployed yet. Please deploy the UC volume in a separate bundle deploy before using it in the artifact_path.
at resources.volumes.bar
in databricks.yml:24:7
```
---------
Co-authored-by: Pieter Noordhuis <pieter.noordhuis@databricks.com>
shreyas-goenka