Libbeat mapstriface.go: Error message is misleading

[alakahakai]

The error message from https://github.com/elastic/beats/blob/master/libbeat/common/schema/mapstriface/mapstriface.go 105 is misleading. It is not displaying the type of the errored value properly. They are always displayed as map[string]interface {}.

2020-05-05T17:46:57.188-0500 ERROR mapstriface/mapstriface.go:105 wrong format in `dataFileVersion`: expected dictionary, found map[string]interface {}
2020-05-05T17:46:57.188-0500 ERROR mapstriface/mapstriface.go:105 wrong format in `extentFreeList`: expected dictionary, found map[string]interface {} 

A type switch should be used there instead of cast.

[elasticmachine]

Pinging @elastic/integrations-services (Team:Services)

[urso]

If by dictionary we mean common.MapStr, then map[string]interface{} should be valid as well. Sometimes we get map[string]interface{} when parsing JSON into a MapStr. Libbeat normally takes care of this by dynamically casting map[string]interface{} to common.MapStr via type switches.