Rubydebug codec not working

hi,
we're using logstash 2.2.2, I have next simple config of logstash:

input {
    file {
        path => "/var/log/logstash/logstash.log"
        codec => "rubydebug"
    }
}
output {
     stdout {
        codec => "json"
     }
}

When I'm running logstash like this:

/opt/logstash/bin/logstash -f logstash.debug.conf

on stdout I receive nothing, while /var/log/logstash/logstash.log is changing (new logs coming) . Than, I tryed to launch it in debug mode:

/opt/logstash/bin/logstash -f logstash.debug.conf --debug

and receive next:

Reading config file {:file=>"logstash/agent.rb", :level=>:debug, :line=>"371", :method=>"local_config"}

          @input_file_1 = plugin("input", "file", LogStash::Util.hash_merge_many({ "path" => ("/var/log/logstash/logstash.log") }, { "codec" => ("rubydebug") }))   
.......
observe_read_file: general error reading /var/log/logstash/logstash.log - error: #<RuntimeError: Not implemented> {:level=>:debug, :file=>"filewatch/observing_tail.rb", :line=>"90", :method=>"observe_read_file"}

Can you tell what is wrong here?

The ruby debug codec is only used for formatting output, and does not even seem to have the method for decoding input implemented. Removing the codec from the file input should therefore remove the problem.

yeah, but logstash log format is not json

what would you suggest to use?

thx

I think that should be mentioned in documentation explicitly. Natural expectation for codec is that it supports both coding and decoding.

Import using the default, plain codec and then use filters e.g. grok, to parse the data.