Loki: Always display log context toggle

[matyax]

The changes in this PR are to always offer Logs Context, independent of the current query.

The reason for this is that log context is created from all labels defining the stream for the selected log line. And it has basically nothing to do with filter being present/not being present. I think that showing log context only when filter is present is actually more confusing as it makes log context associated with line filters, when it should be associated with log line labels/streams.

This PR adds support for offering logs context for logs lines generated using negative filters.

Since deciding to show or not show the logs context toggle depends on the presence of search words https://github.com/grafana/grafana/blob/main/public/app/plugins/datasource/loki/datasource.ts#L821 ; and search words were based on the presence of PipeExact or PipeMatch nodes, the code has been changed to also look for Neq and Nre nodes. When these are present, the search words are prepended with -. For example, != word is processed as -word.

The other alternative was adding a new function to look for Neq and Nre in the query, and add a new custom property returned from the backendResultTransformer as, for example, custom.hasNegativeExpressions https://github.com/grafana/grafana/blob/main/public/app/plugins/datasource/loki/backendResultTransformer.ts#L4 ; and then updating logsSeriesToLogsModels and the LogsModel type, to pick up this property and return it for every row. https://github.com/grafana/grafana/blob/main/public/app/core/logsModel.ts#L426

I decided for the alternative I sent in this PR because it was simpler and didn't require more parsing, new properties, or type updates.

Which issue(s) does this PR fix?:

Fixes #66132

Special notes for your reviewer:

Returning negative expressions as negative search words didn't seem to have any visible harmful effect, and allowed us to offer logs context for these queries. Nothing should be broken after these changes.

To test, write any query with negative expressions and see the logs context toggle for each row:

Now we will always display the button for logs.

[github-actions]

Backend code coverage report for PR #66379
No changes

[github-actions]

Frontend code coverage report for PR #66379

Plugin	Main	PR	Difference
loki	84.62%	84.64%	.02%

[ivanahuckova]

I think that to fix #66132, we should consider always showing log context. And the more I am thinking about it, the more I think it make sense to always show log context toggle.

The reason for this is that log context is created from all labels defining the stream for the selected log line. And it has basically nothing to do with filter being present/not being present. I think that showing log context only when filter is present is actually more confusing as it makes log context associated with line filters, when it should be associated with log line labels/streams.

So before moving with this PR that introduces negative searchWords (that still acts in Highlight component like normal searchWords because - has no effect on showing/not showing highlighted text), I would consider just showing context all the time.

What do you think @grafana/observability-logs?

[svennergr]

What do you think https://github.com/orgs/grafana/teams/observability-logs?

Makes sense to me. Should we do it before G10?

[matyax]

Thank you @ivanahuckova. Always showing the context button makes sense to me as well 👍

I can do that in this PR if we all agree.

[gabor]

What do you think @grafana/observability-logs?

👍

[matyax]

@svennergr One thing I noticed after this is that it seems to be ignoring the log line immediately above the one I'm expanding:

[svennergr]

@svennergr One thing I noticed after this is that it seems to be ignoring the log line immediately above the one I'm expanding:

I guess that logline has different labels than the others. You can set the logsContextDatasourceUi feature flag and remove some labels. It should appear at one point.

[svennergr]

LGTM.

I am wondering if we should mark showContextToggle here https://github.com/grafana/grafana/blob/0457291ac2cfc987985c805e0f03282861c695e9/packages/grafana-data/src/types/logs.ts deprecated and remove that functionality at one point completely.

[matyax]

I think we should, @svennergr , as every showContextToggle I see is just returning true. #66819