Add hosts and K8s quickstarts to stateful docs

[dedemorton]

Ports hosts quickstart added in #4073 to stateful.

Also makes a few changes to the serverless files to sync them with this PR.

[github-actions]

A documentation preview will be available soon.

• 🔨 Buildkite builds
• 📚 HTML diff
• 📙 Preview page

Request a new doc build by commenting

• Rebuild this PR: run docs-build
• Rebuild this PR and all Elastic docs: run docs-build rebuild

_{run docs-build is much faster than run docs-build rebuild. A rebuild should only be needed in rare situations.}

_{If your PR continues to fail for an unknown reason, the doc build pipeline may be broken. Elastic employees can check the pipeline status here.}

[mergify]

This pull request does not have a backport label. Could you fix it @dedemorton? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-/d./d is the label to automatically backport to the /d./d branch. /d is the digit
  NOTE: backport-skip has been added to this pull request.

[dedemorton]

@alaudazzi Do you want me to port your changes, too, or do you want to do that?

[dedemorton]

@akhileshpok @thomheymann Who is the best person to ask about the privileges required to perform the steps in the hosts quickstart? Also can you please confirm that the hosts quickstart is available in 8.15? I spun up a cluster on cloud last week, and did not see the onboarding UI that I was expecting.

[alaudazzi]

@dedemorton please go ahead and port my changes. Thank you and sorry for the late reply.

[dedemorton]

I have the same question about K8s monitoring (which I added today): what should we document for required privileges when using stateful?

[akhileshpok]

@dedemorton - The hosts and the K8s quickstarts will only become available in stateful in 8.16. They are currently available on serverless. Is your question around required privileges focusing on Elasticsearch, Kibana or something else? Root level privileges are required to install an Elastic Agent for both of these quickstarts.

[dedemorton]

Is your question around required privileges focusing on Elasticsearch, Kibana or something else?

@akhileshpok Yes, I mean are there any Elasticsearch/Kibana privileges that might be required for users who are using a stateful cluster (for serverless, we've documented that the Admin role is required).

[akhileshpok]

@thomheymann - Do you have any inputs on the above question related to ES/Kibana privileges? Thanks

[thomheymann]

@dedemorton Users need the following privileges to use data onboarding:

• cluster privileges: ['monitor', 'manage_own_api_key']
• index privileges: { names: ['logs-*-*', 'metrics-*-*'], privileges: ['auto_configure', 'create_doc'] }
• kibana privileges: { spaces: ['*'], feature: { fleet: ['all'], fleetv2: ['all'] } }

The builtin role that has these privileges is the superuser role

[dedemorton]

Noting here that backport-skip label is set because we don't yet have a branch for 8.16. Everything in master will end up in 8.16 when we create the branch.

[dedemorton]

@alaudazzi Can you take a look at my changes in this commit to make sure you agree with the consistency changes that I"ve applied?

[mdbirnstiehl]

A couple of small things but otherwise LGTM!

[elasticdocs]

🚀 Built elastic-dot-co-docs-preview-docs successfully!

• https://elastic-dot-co-docs-production-kzf6afjui-elastic-dev.vercel.app

• Built with commit 0f03de3

Issues? Visit #next-docs in Slack

[alaudazzi]

LGTM

[dedemorton]

@akhileshpok I'm going to merge this because it's blocking another PR I have in progress. If you have any concerns with the changes here, just open a docs issue, and we will address your concerns. Thanks!