[Transforms UI] When adding Runtime fields, doesn't support adding a Lookup Runtime Field

[BenB196]

Kibana version:
8.5.3

Elasticsearch version:
8.5.3

Server OS version:
N/A

Browser version:
N/A

Browser OS version:
N/A

Original install method (e.g. download page, yum, from source, etc.):
N/A

Describe the bug:

I'm attempting to add a runtime field that is of type lookup. However, the Kibana UI doesn't recognize this Runtime field type and therefore doesn't let me add it.

Steps to reproduce:

1. Attempt to create a new transform
2. Attempt to add a new runtime field of type lookup.
3. Observe that the "Apply Changes" button is grayed out.

Expected behavior:

I would expect to be able to add any type of runtime field to the transform via the UI.

Screenshots (if relevant):

Working example of a standard script runtime field:

Not working example of a lookup field:

Errors in browser console (if relevant):

Provide logs and/or server output (if relevant):

Any additional context:

[elasticmachine]

Pinging @elastic/kibana-data-discovery (Team:DataDiscovery)

[elasticmachine]

Pinging @elastic/response-ops (Team:ResponseOps)

[mattkime]

@BenB196 Kibana doesn't yet support the lookup type for data views. Alternatively you might add the field to the index mappings although it might be a bit more troublesome.

[BenB196]

Hi @mattkime thanks for the additional information. I hadn't considered adding the lookup field to the index mapping, but thinking about it a bit, I don't think in this case it would be feasible. This issue was spurred while looking into this discussion, and I don't think there would be a "good" case for adding this type of mapping to the core of something like metrics-*

[kertal]

Closing this because it's not planned to be resolved in the foreseeable future. It will be tracked in our Icebox and will be re-opened if our priorities change. Feel free to re-open if you think it should be melted sooner.