Allow index pattern with no matching data

[ogupte]

Describe the feature:
Allow index patterns to be created without matching indices, so that the messaging doesn't appear to be an error.

Describe a specific use case for the feature:
Right now APM automatically creates the apm index pattern on server startup if it doesn't already exist. The goal is to make the query bar in the APM UI, which relies on the index pattern, work automatically.

If that happens on a fresh instance without any data, the user sees this messaging:

It indicates that something is wrong, when there's really no error.

To reproduce: start kibana 7.2 snapshot or newer with a fresh elasticsearch and navigate to discover.

[elasticmachine]

Pinging @elastic/kibana-app-arch

[dolaru]

FYI, having the apm-* index pattern present on a fresh deployment inhibits the first-time splash screen from kicking in. (the one that asks you if you want to restore sample data, or explore on your own)

[sorenlouv]

I suggest the error/warning is removed. There are valid reasons for creating the index pattern before data ingestion starts.

@spalger @cjcenizal Saw you had previously touched this part of the code base (#10788). What do you think the best course of action is?

[cjcenizal]

@ogupte Could you update the PR description with steps to reproduce and a screenshot of the entire Kibana UI so we can see the context of that error?

I've lost context on this a bit, so I'll offer an opinion but defer to the @elastic/kibana-app-arch team.

Does the error appear no matter where you are in Kibana, or only appear if you try to view that index pattern, e.g. in Discover or Visualize? If the former then I agree we should remove it. But I think it's useful to surface this information to the user if they're trying to consume an index pattern that doesn't capture any data, especially if the cause is as granular as "This index pattern captures no indices". Then they'll be able to figure out why there are no indices and possibly solve the problem.

In this situation, I'd suggest surfacing the information more contextually, e.g. as a callout inside of the area where the user expects to see the content of the index pattern, such as Discover's doc table or the Visualize visualization. The Design team also has some patterns around this.

[sorenlouv]

I haven't reproduced this but @ruflin said:

If I setup a fresh Elastic Stack (master) and then for fun click on APM but then don't use it and go back to discover, I see the following error.

I think the behaviour with showing the error is ok-ish. What is concerning is:

FYI, having the apm-* index pattern present on a fresh deployment inhibits the first-time splash screen from kicking in. (the one that asks you if you want to restore sample data, or explore on your own)

[graphaelli]

Description updated with some more context and the step to reproduce.

[elasticmachine]

Pinging @elastic/apm-ui