Can elasticsearch extract the contents of the log through a custom template?

I want to store the contents of the log read through logstash in elasticsearch, but the contents of the log are stored in the message field. Can I use a custom template to extract the contents of the log as a certain field?
for example, is there an ip:xxxx, in the log that can extract ip and its ip as a field? I also looked at the templates on the
website and the documents on the official website. They all seemed to define a type for the field, and they didn"t use regular matching to extract specific data, so I couldn"t understand

.
Mar.29,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b35c98-4ec27.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b35c98-4ec27.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?