[Fleet][Integrations] Show changelog on upgrading integration

[philippkahr]

Kibana version: 7.16.0

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

Describe the bug:

There are "two" issues.

1. The windows integration is has released 1.5.0 version. I was still running 1.2.2.
2. When going to the integration page and then selecting the windows event log integration, I got the "update available" checkmark warning.
3. When going through the agent policies, it showed me that there is an update available for multiple integrations but not for the windows event one. (Jen 1/4/21: not a bug, see [Fleet][Integrations] Show changelog on upgrading integration #121064 (comment))

Second issue:

1. The checkmark warning with the "update available" is nice, but it would be cool if I can click on it and immediately decide whether I want to update or not.
2. When hitting update, a short release note statement should be shown, telling me what is broken and what was fixed and why I should update in the first place.

Steps to reproduce:

1. Don't really know how to be honest. Attached you find a screencast of this issue.

Expected behavior:

1. Show me the update button inside the agent policies.

Screen.Recording.2021-12-13.at.12.16.06.mov

[elasticmachine]

Pinging @elastic/fleet (Team:Fleet)

[jen-huang]

When going through the agent policies, it showed me that there is an update available for multiple integrations but not for the windows event one.

This is because for the other integrations, you already upgraded the integration itself, but the integration policies themselves have not been upgraded to the latest version available on your instance.

When hitting update, a short release note statement should be shown, telling me what is broken and what was fixed and why I should update in the first place.

Thank you for the enhancement ideas. Package authors can publish change logs between versions that we can display, though I suppose we may be displaying a lot of changelogs depending on how many versions have passed since the user's existing version.

[aarju]

+1 to either displaying or having a direct link to the change log for an integration when applying an update. The Integration change logs also need to improve to describe exactly what changed in the update. At this time the Changelog only shows a list of the Pull Requests with a small description that doesn't always fully describe what was changed in that PR.

[nimarezainia]

@aarju agreed the documentation on the changelogs needs to be improved we will be tracking that.
Integrations "settings" tab has all the version information, perhaps that can pull in the changelog or point t the docs for changelog. @kpollich thoughts?

[kpollich]

@nimarezainia - Agree that surfacing the changelog somewhere would be great. During the upgrade flow makes sense, as well as somewhere on the integration details page. We should have the data available in code, it's just a matter of rendering the changelog in a meaningful way.

See an example of what changelogs look like here: https://github.com/elastic/integrations/blob/main/packages/nginx/changelog.yml

[joshdover]

@nimarezainia @mukeshelastic I suspect having a solution to this to be important for the TSDB project. We need to be able to give users plenty of information about their package getting support for TSDB for two reasons:

• We want to advertise the new storage saving and query performance benefits of TSDB to encourage adoption
• At some point, we plan to only support TSDB indexing for future versions of integrations. This has some cluster sizing implications and we need to give users plenty of warning before they upgrade to these new package versions.

[nimarezainia]

@kpollich @jen-huang should this and elastic/integrations#5142 be linked and one closed (perhaps this one should be closed as the other has more details)

[kpollich]

Closing in favor of #150754

[kpollich]

@nimarezainia I've closed both, as the implementation issue Jen created against the Kibana repo most accurately summarizes the scope here. This enhancement will only touch Kibana code, so let's track it in Kibana.