= fluent-plugin-filter

== Component

=== FilterOutput

Filtering messages by simple allow/deny rules.

== Installation

Add this line to your application's Gemfile:

    gem 'fluent-plugin-filter'

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install fluent-plugin-filter

== Configuration

=== FilterOutput

Filter out messages contains <tt>{status : 404}</tt> :

    <match accesslog.**>
      type filter
      all allow
      deny status: 404
    </match>
    <match filtered.**>
      type stdout
    </match>

in above configuration, <tt>{status: 404}</tt> is filtered out and <tt>{status: 200}</tt>, <tt>{status: 303}</tt>, <tt>{status: 401}</tt> passed.
Messages passing filter are add_prefix (default filtered.)

So you catch "filtered" tag and do next process.

You can use int, float, string, regexp in value.

=== FilterFilter

In fluentd >= 0.12, we can use `filter` declarative. So release Filter filter:

    <filter accesslog.**>
      type filter
      all allow
      deny status: 404
    </filter>

Thanks to @cosmo0920

=== Parameters

==== all <allow|deny>
Specify basic policy.

==== allow field:<Pattern> / deny field:<Pattern>
Specify each field policies.
If a value for the field matches the pattern, the allow or deny rule is applied.

===== Pattern := <String|Integer|Float|Regexp>

Patten is parsed by following rules.

* Integer: a value consisted of degits without ".". e.g. status:200, price:10000
* Float: a value consisted of degits with "." (if you force the value float, set 200.0). e.g. average:145.0
* Regexp: a value starting with "/" and end with "/". e.g. path:/\/user\/\d+/
  * thx @mmacvicar !
* String: a value unmatched below rule or enveloped with \" or \'.

== Contributing

1. Fork it
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Added some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create new Pull Request