[Synthetics UI] Kibana should display a proper error message when there are no locations available

[lucasfcosta]

Kibana version: 8.3.0-SNAPSHOT onwards. 8.2.x works fine.

Elasticsearch version: 8.3.0-SNAPSHOT onwards.

Original install method (e.g. download page, yum, from source, etc.): Elastic cloud clusters pointing to the staging manifest of the service.

Describe the bug:

The Kibana instance can never get access to the Synthetics Service, even when its enabled.

UPDATE: That's because we must set showExperimentalLocations to true in our production deployments. Otherwise, non-GA locations of the service do not appear.

Steps to reproduce:

1. Add your account's ID to the allow-list for the service (in staging)
2. Create a new cloud deployment (make sure to use the CFT region)
3. Update the xpack.uptime.service.manifestUrl to point to the service's staging manifest
4. Once Kibana restarts, go into Monitor Management and enable it

You're not able to access the service.

If you set xpack.uptime.service.showExperimentalLocations to true, everything should work fine.

Expected behavior:

Kibana should display a proper error message when there are no GA locations available.

CC @hbharding we may need help with the phrasing/designs here.

Screenshots (if relevant):

[elasticmachine]

Pinging @elastic/uptime (Team:uptime)

[lucasfcosta]

This is actually not a blocker nor an actual bug with the service or Kibana not working. We simply had incorrect expectations about incorrect configurations.

👉 This issue has been updated to reflect that.

1. By default, clusters in production will hide locations that aren't marked as ga.
2. That's the desired behaviour to prevent users from seeing new locations we deploy. We can, however, test those locations in production by setting showExperimentalLocations.
3. As expected, our locations in staging are not ga. That's why any deployments in the staging cloud set the showExperimentalFlag to true by default: so that they can see these locations.

In our deployment in production, we forgot to set that flag. That's all.

[paulb-elastic]

I'm assuming this is now more of a Synthetics UI requirement, so I've updated the description accordingly.

[paulb-elastic]

Closing as this isn't a problem now. Having discussed with @dominiqueclarke, locations are fetched on each sync and cached in Kibana. If we don't detect service locations, it's assumed to be a self-managed deployment and we show them that flow.