Elasticsearch: Fix passing of limit and datalinks to logs data frame

[ivanahuckova]

In this PR we are fixing processing of log response on backend by adding limit to meta and also by enhancing dataFrame with data links.

Similarly as with searchWords, the dataFrames processed on backend have searchWords and limit in meta.custom. Therefore in logsModel, we need to make sure that we read at both places.

Fixes #68427

How to test:

• Run logs query with enableElasticsearchBackendQuerying enabled and make sure that in Explore, you see limit displayed in meta.

[github-actions]

Backend code coverage report for PR #68554

Plugin	Main	PR	Difference
elasticsearch	86.6%	86.6%	0%

[github-actions]

Frontend code coverage report for PR #68554

Plugin	Main	PR	Difference
elasticsearch	81.68%	81.54%	-.14%

[gabor]

LGTM 👍

there's one thing though..

i wonder if it's a good idea to read frame.meta.custom in logsModel.ts. we are kind of making certain custom values not-custom.
(i understand that we have been doing it before with the custom-frame-type and also with searchWords).

maybe we could just make sure the javascript-dataframe-meta is in sync with go-dataframe-meta instead.
and in the meantime, while we are waiting for that to be done,
we could have a small function in elastic/datasource.ts that transforms a "backend dataframe" to "frontend dataframe" by adjusting the location of searchWords and limit.

not sure.
wdyt?

[ivanahuckova]

@gabor based on this I would expect it being the other way around. So after this PR is merged elasticsearch does it correctly and we should make sure that other data sources use custom.

[gabor]

@gabor based on this I would expect it being the other way around. So after this PR is merged elasticsearch does it correctly and we should make sure that other data sources use custom.

oh, interesting, i did not see that comment there 👍

[grafanabot]

The backport to v10.0.x failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new branch
git switch --create backport-68554-to-v10.0.x origin/v10.0.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x dbbbc46351d81b1c97f8dfaed25f6f0609797967
# Push it to GitHub
git push --set-upstream origin backport-68554-to-v10.0.x
git switch main
# Remove the local backport branch
git branch -D backport-68554-to-v10.0.x

Then, create a pull request where the base branch is v10.0.x and the compare/head branch is backport-68554-to-v10.0.x.