Filter Plugins
Filter plugins enables Fluentd to modify event streams. Example use cases are:
- 1.Filtering out events by grepping the value of one or more fields.
- 2.Enriching events by adding new fields.
- 3.Deleting or masking certain fields for privacy and compliance.
It is used with the
<filter> directive as follows:<filter foo.bar>
@type grep
regexp1 message cool
</filter>
The above directive matches events with the tag "foo.bar", and if the "message" field's value contains "cool", the events go through the rest of the configuration.
Like the
<match> directive for output plugins, <filter> matches against a tag. Once the event is processed by the filter, the event proceeds through the configuration top-down. Hence, if there are multiple filters for the same tag, they are applied in descending order. Hence, in the following example,<filter foo.bar>
@type grep
regexp1 message cool
</filter>
<filter foo.bar>
@type record_transformer
<record>
hostname "#{Socket.gethostname}"
</record>
</filter>
Only the events whose "message" field contain "cool" get the new field "hostname" with the machine's hostname as its value.
Users can create their own custom plugins with a bit of Ruby. See this section for more information.
If this article is incorrect or outdated, or omits critical information, please let us know.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.
Last modified 3yr ago