Document Fleet Server prereqs for ECE

[dedemorton]

For Fleet Server to work, ECE needs several prerequisites:

• ECE 2.10 or higher and Elastic Stack 7.13 or higher to get APM & Fleet Slider
• Requires additional wildcard domains and certificates (which normally only cover *.cname, not ..cname). This enables us to provide the URL for Fleet Server of https://.fleet.:
• The template must contain a slider for APM & Fleet. Link to docs describing how to add it if its missing.

[mostlyjason]

@dedemorton updated the list of prerequisites

[dedemorton]

I've added this info to the docs in #731 but I've temporarily commented it out until ECE 2.10 is live.

[dedemorton]

Noting here that we also need to provide a link to the documentation about wildcard domains and certificates when that info is available. We can track progress here: https://github.com/elastic/cloud/issues/80384

[dedemorton]

Still waiting for 2.10 to go live (can't do anything here until it does).

[mostlyjason]

@dedemorton can we add a note about the Fleet Server requirements to ECE 2.9 as well? A user ran into a problem that Fleet Server isn't working on ECE 2.9. ECE 2.10 is a known requirement, but its not documented anywhere visible to 2.9 users. The recommended path for 2.9 users is to create a self-hosted Fleet Server instead of using the one in the APM & Fleet slider.

[dedemorton]

Yah, that's a good point. I think we're close enough to 2.10 that I should just make the content live (without a link) in the Fleet Server docs.

[dedemorton]

OK, so I've made the info about 2.10 live in the Fleet Server docs: #778

Regarding the question about updating the 2.9 ECE docs, I'll defer to the cloud team. Typically we don't update older versions to discuss future functionality. @kellyemurphy WDYT? Would this be feasible? Make sense? Should I create an issue against the cloud docs?

[dedemorton]

@mostlyjason Can you help me close out this issue?

The final task is to add a link to the cloud docs about the Fleet Server requirement to add wildcard domains and certs (which normally only cover *.cname, not *.*.cname).

Is that still a requirement? When I went through the discussion and related PRs, it was hard to figure out the final resolution, and I was unable to find any docs that mention cname and Fleet.

Noting here that I also need to fix our docs because GitHub gobbled the asterisks in *.*.cname. They say:

Requires additional wildcard domains and certificates (which normally only cover *.cname, not ..cname). This enables us to provide the URL for Fleet Server of https://.fleet.

[mostlyjason]

Yes this is still required I'll forward an email to you with some more details

[dedemorton]

Since the remaining work here is more involved than simply adding a link, I've created a new issue to track this: #825

I will close this issue after putting a PR up to fix the error in the prereqs.

[dedemorton]

Opened a PR to add the missing asterisks: #829. Closing out this issue now.