FLUENT CUSTOM PLUGIN

[kandula-uday]

hi All, Can anyone please help me with this? I am developing a custom plugin that will take Regular expression and search the pattern in the message

config_section :rule, param_name: :rules, multi:true do

config-param : pattern_regexp, :regexp, default :/^$/

def configure(conf)
super
@rp = conf['pattern_regexp']
puts @rp
end

def filter(tag, time, record)
record.each do |key, value|
if value =~ @rp
end
record
end
end
end

conf. file

@Mask

pattern_regexp /[a-zA-Z0-9.]+t$/

but I am getting nil class.. @rp is not holding the conf value of pattern_regexp i am getting nil error

[daipom]

I think this will be helpful.

https://github.com/fluent/fluentd/blob/v1.15.3/lib/fluent/plugin/filter_grep.rb#L44-L49
https://github.com/fluent/fluentd/blob/v1.15.3/lib/fluent/plugin/filter_grep.rb#L115-L118

@rules.each do |rule|
  p rule.pattern_regexp
end

[kandula-uday]

Thank You Daijiro Fukuda it worked. May I know why @rp = conf['pattern_regexp'] not holding the value of pattern_regex from conf file

[daipom]

We can not get config_section values from conf by hash[].
I don't know the reason, but we don't need it.

We can use configured parameters by instance variables or accessors.
Usually, all we have to do is defining config_param or config_section and so on.

Overriding configure(conf) is for some processes after parsing the config (which is done in super).
Usually, we don't have to use conf value, since it is just for overriding.

def configure(conf)
  super
  # some processes such as validating
  validate(@rules)
end

[kandula-uday]

so ,any instance variables to be used in the functions are defined or initialized in def configure(conf)

[daipom]

The config values which you define by config_param or config_section are initialized as instance variables and accessors in super of def configure(conf).