I understand that Logstash is for aggregating and processing logs. I have NGIX logs and had Logstash config setup as:
filter {
grok {
match => [ "message" , "%{COMBINEDAPACHELOG}+%{GREEDYDATA:extra_fields}"]
overwrite => [ "message" ]
}
mutate {
convert => ["response", "integer"]
convert => ["bytes", "integer"]
convert => ["responsetime", "float"]
}
geoip {
source => "clientip"
target => "geoip"
add_tag => [ "nginx-geoip" ]
}
date {
match => [ "timestamp" , "dd/MMM/YYYY:HH:mm:ss Z" ]
remove_field => [ "timestamp" ]
}
useragent {
source => "agent"
}
}
output {
elasticsearch {
hosts => ["localhost:9200"]
index => "weblogs-%{+YYYY.MM}"
document_type => "nginx_logs"
}
stdout { codec => rubydebug }
}
This would parse the unstructured logs into a structured form of data, and store the data into monthly indexes.
What I discovered is that the majority of logs were contributed by robots/web-crawlers. In python I would filter them out by:
browser_names = browser_names[~browser_names.str.\
match('^[\w\W]*(google|bot|spider|crawl|headless)[\w\W]*, na=False)]
However, I would like to filter them out with Logstash so I can save a lot of disk space in Elasticsearch server. Is there a way to do that? Thanks in advance!