Kibana: [Logs UI] Make column width proportions configurable

[jasonrhodes]

Following on from the discussion in #39703, we decided to move forward with making logs column width proportions configurable.

AC:

• In the settings tab for the source configuration in the Logs UI, each chosen column has a field that allows the user to adjust the CSS "flex-grow" value that will be applied to that column and its header -- this should default to whatever the current values are for our existing default columns, or "1" for new columns added
• The timestamp field should be left as-is, calculated to auto adjust to the number of characters in the current timestamp format (this won't be configurable at all for now)

Note: should we also consider looking at the newer EUI data table for the Logs UI? https://github.com/elastic/eui/issues/1689

[elasticmachine]

Pinging @elastic/infra-logs-ui

[Zacqary]

What should the UI for this look and feel like? Is it literally just a text box to change the flex-grow value, or should we abstract that value away somehow?

Also, is the Message column adjustable? I noticed that it's no longer possible to move the Message column to anywhere but the final position, so I'm wondering if like the Timestamp column it should just be frozen.

[katrin-freihofner]

I think the EUI data grid would solve this issue. The column width can be adjusted by dragging the borders. https://elastic.github.io/eui/#/tabular-content/data-grid

[weltenwort]

It doesn't have the virtualization capabilities we need right now, though. And something like the nice timestamp header from #45986 or other customization in the stream rendering could become difficult to implement.

I'm keeping an eye on the data grid in regard to using it as a rendering mechanism for the logs stream, but it's not quite there yet IMHO.

[kycfeel]

Any update on this? I'm looking forward to replacing my logtrail plugin on kibana to this native logs app, but it is almost unusable due to the reconfigurable width between data fields.

I simply want to reduce that blank space between kubernetes.lables.app and log fields in this screenshot.

[weltenwort]

@mukeshelastic FYI

I think it might be worth investigating how easily we could add virtualized scrolling support to the EUI datagrid component which would then make things like column resizing easier.

[cschar]

Is this feature on the roadmap for 2020? In the meantime is there a good alternative plugin ?

[beanaroo]

Plenty of whitespace in this screenshot too on Kibana 7.10.0