Hello,
I'm trying to unify some of our fields to be the same case. Now we have TARGET_INDEX
and target_index
I have tried to apply mutate lowercase filter as described in the documentation:
mutate {
lowercase => ["TARGET_INDEX"]
# rename => { "TARGET_INDEX" => "target_index" }
remove_field => ["tags", "@version"]
}
On the output and also in the index I see an uppercase field. When I use rename it works as expected - I see it in the output and in the index.
This mutate is the first in the list of filters. Why lowercase may not work?
Logstash version: logstash 7.0.1
Thank you!