I am reading data from files by defining path as *.log etc,
Files names are like app1a_test2_heep.log , cdc2a_test3_heep.log etc
How to configure logstash so that the part of string that is string before underscore (app1a, cdc2a..) should be grepped and added to host field and removing the default host.
Eg:
fileName: app1a_test2_heep.log
host => app1a
Thanks in advance, Ravi