[Website]: Elastic Agent Providers should not be under the standalone tree

[herrBez]

Type of issue

None

What documentation page is affected

https://www.elastic.co/docs/reference/fleet/providers

What happened?

Currently, the documentation shows that Elastic Agent providers are under the 'standalone' tree (e.g., https://www.elastic.co/docs/reference/fleet/env-provider).

This isn't entirely accurate, as providers are also available on Fleet Server. They are pre-configured there, particularly the host, Kubernetes, and env providers. Listing providers under 'Standalone' creates an odd effect: there are part of the Fleet documentation like this page that points to the standalone section, causing unnecessary confusion.

Additional info

Related issues:

• [Internal]: Fleet Managed Integration Scaling document improvement #2166
• [Website]: Fleet environment providers are badly explained #1928

[vishaangelova]

I agree that the Set environment variables in an Elastic Agent policy doc (which is under
Centrally manage Elastic Agents in Fleet) needs to be reviewed and updated to provide more detailed information. We will handle this in #1928.

As to the request to move the Providers docs from under the "Configure standalone Elastic Agents”, I’d like to request more information from @ebeahan or @blakerouse regarding the availability of the providers on Fleet Server:

• Is it a correct assumption that providers can be configured on a standalone Fleet Server in elastic-agent.yml, but that they cannot be configured on Fleet-managed Fleet Servers?
• Is it also the case that for Fleet-managed Fleet Servers you can reference a predefined set of host metadata (e.g., host.name) and use environment variables in the agent policy or integration policy config fields (e.g., ${env.foo} or ${env.foo|’’} as suggested in this comment), but that you cannot add provider configuration blocks to these policies?

If these assumptions are true, then I think we should leave the Provider docs in their current place, and:

• Modify the title and text of the Configure providers for standalone Elastic Agents doc to include a reference to the standalone Fleet Server as well.
• Update the Set environment variables in an Elastic Agent policy doc with detailed information that is specific to using these variables in Fleet-managed Elastic Agents and Fleet-managed Fleet Server configurations as part of [Website]: Fleet environment providers are badly explained #1928.

(cc: @colleenmcginnis, @nimarezainia)