gistfile1.txt

<source>
  type tail
  format apache2
  path /var/log/apache2/access_log
  tag apache.access
  pos_file /tmp/fluent.log.pos
</source>

<match apache.access>
  type       exec_filter
  command    ruby /path_to_file/parse.rb
  in_format  json
  out_format msgpack
  tag        apache.parsed
  flush_interval 10s
</match>

<match apache.parsed>
  type mongo
  database fluent
  collection test
  flush_interval 10s
</match>