Hello,
Beats do not automatically check for settings in keystore as ElasticSearch does. To solve your problem you need to add the settings to your yml file and reference the keys from your keystore:
output.elasticsearch:
username: "${output.elasticsearch.username}"
password: "${output.elasticsearch.password}"
I prefer this way over the ElasticSearch way as it is more readable (you do not have to assume that settings missing here are stored in the keystore) and you can rename the keys in the keystore to better describer what they contain(e.g. output.prod-cluster-1.username instead ofoutput.elasticsearch.username).
Best regards
Wolfram