I am following the steps in this blog to set up rsyslog + logstash + graylog2 and I can't figure out how to replace the @source_host attribute in logstash using the mutate -> replace filter.
In the exmaple the author replaces his @source_host with a string value but I'd like to use the actual value that is parsed from in this case a syslog.
mutate {
type => loc1
replace => ["@source_host", "loc1"]
}
mutate {
type => loc2
replace => ["@source_host", "loc2"]
}
How do I actually maintain the original source host in my logs?