Parser Plugins

Fluentd has 6 types of plugins: Input, Parser, Filter, Output, Formatter and Buffer. This article gives an overview of Parser Plugin.


Sometimes, the format parameter for input plugins (ex: in_tail, in_syslog, in_tcp and in_udp) cannot parse the user's custom data format (for example, a context-dependent grammar that can't be parsed with a regular expression). To address such cases. Fluentd has a pluggable system that enables the user to create their own parser formats.

How To Use

  • Write a custom format plugin. See here for more information.

  • From any input plugin that supports the "format" field, call the

    custom plugin by its name.

Here is a simple example to read Nginx access logs using in_tail and parser_nginx:

@type tail
path /path/to/input/file
format nginx
keep_time_key true

List of Built-in Parsers

3rd party Parsers

If you are familiar with grok patterns, grok-parser plugin is useful. Use < 1.0.0 versions for fluentd v0.12.

List of Core Input Plugins with Parser support

with format parameter.

If this article is incorrect or outdated, or omits critical information, please let us know. Fluentd is a open source project under Cloud Native Computing Foundation (CNCF). All components are available under the Apache 2 License.