We have a repo that we use to run Agent (and other Fleet related) tests:
https://github.com/elastic/e2e-testing

When Agent shifted to use Fleet server adjusted the available tests, here:
elastic/e2e-testing#438
Though we still need to flesh out and implement deeper actual Fleet Server tests:
elastic/e2e-testing#1266

Still, with the coverage we have, we can make use of those tests in the actual Fleet-Server repo CI, which is what this ticket is in support of. We need to itemize what details we need of:

• the Fleet Server repo compilation of the artifacts
• - does this include how to build a Docker image with an updated Fleet server from source?
• and how to make use of the newly compiled artifacts to be built into Elastic Agent artifact(s)
• Then, in the fleet-server repo we need to add more to the ci jenkins file, managed in the other issue

The ci hook will run a desired set of e2e-testing scenarios like what we have done for Agent and Kibana. Reference this groovy file for info:
https://github.com/mdelapenya/beats/blob/921a3d52e60db04e0c92712203f097157f290265/.ci/packaging.groovy

This ticket is for documenting the knowledge and steps / logistics.

There is a separate ticket for implementing e2e-testing side changes, here:
elastic/e2e-testing#1411