Run performance testing for Kibana in ECE setup

[mshustov]

The initial implementation of the Kibana single-user performance testing starts KIbana server with the default configuration #117861

Since we are a Cloud-first company, we must ensure that Kibana running on Elastic Cloud provides the best possible User Experience.

The way Elastic runs Kibana on Cloud is quite different from the on-prem configuration. Two main differences are:
Two main differences are:

• Kibana is run on different environments and hardware
• Cloud pre-configures Kibana for the Cloud use-case.

We cannot run performance testing directly on Cloud due to the first limitation - we don’t have control over the runtime environment and hardware. Therefore, there will be additional noise from the unstable environment, which will skew metrics and interfere with tracking long-term performance trends.
We're going start with performance testing on a bare-metal machine to overcome the problem.
However, in the long term, we want to run Kibana via ECE on the bare-metal server to replicate the Cloud environment.

The second problem can be addressed even sooner. The instance running on a bare-metal machine can already use the Kibana configuration defined by Cloud to mimic the runtime configuration close to Cloud.

[elasticmachine]

Pinging @elastic/kibana-operations (Team:Operations)

[spalger]

We decided not to reduce the number of variables in the single-user performance tests. Running the services directly is the best way to do that. The numbers we're trying to capture shouldn't be environment specific.

A performance test of the cloud containers doesn't sound like a useless exercise, but I think it would be separate from the single user performance testing we are working on now.