API key authentication for cross-cluster search & detection rules

[joepeeples]

Description

Currently our cross-cluster search (CCS) docs mention the API key authentication method but don't explain it in more detail. We can expand the docs to provide more guidelines as a fully supported option.

@vgomez-el has done testing to confirm the method, with these additional caveats:

• Pay attention to the API key expiration. Once the key expires, users won't be able to connect to remote clusters.
• Pay attention to the indices permissions when creating the API key, otherwise users will need to create a new API KEY and start the process again.
• For cloud deployments, all deployments must be on the same region.
• Carefully follow the prerequisites and other documentation for API key auth in CCS.

Confirmed in 8.10, version when API auth was added in general, but for cross-cluster search it was in beta until 8.14. Either backport to 8.14, or backport further to 8.10 and add the beta tag.

Background & resources

• PRs: n/a
• Issues/metas: ??
• Point of contact: @vgomez-el
• Test environments: ??

Which documentation set does this change impact?

ESS only

ESS release

N/A

Serverless release

n/a

Feature differences

n/a

API docs impact

??

Prerequisites, privileges, feature flags

??

[joepeeples]

New info: API auth for cross-cluster search was added in 8.10, but it was in beta until 8.14. Updated description above with backporting options to consider.