Plugin keeps reconnecting/crashing

[lenisko]

• Version:
  elasticsearch 7.5.1
  logstash 7.5.1
  logstash-input-irc-3.0.7
• Operating System: Ubuntu 18.04.3 LTS
• Config File (if you have sensitive info, please remove it):

input {
    irc {
        channels => ["#xxx", "#xxx"]
        host => "irc.pirc.pl"
        port => 6697
        secure => true
        catch_all => true
        get_stats => true
        nick => "xxx"
        real => "xxx"
        user => "xxx"
    }
}

output {
    elasticsearch {
        hosts => "localhost"
        index => "logstash-irc-%{+YYYY.MM.dd}"
    }
}

• Sample Data:

Dec 21 04:27:01 saya logstash[26428]: [2019-12-21T04:27:01,808][ERROR][logstash.javapipeline    ][main] A plugin had an unrecoverable error. Will restart this plugin.
Dec 21 04:27:01 saya logstash[26428]:   Pipeline_id:main
Dec 21 04:27:01 saya logstash[26428]:   Plugin: <LogStash::Inputs::Irc nick=>"xxx", channels=>["#xxx", "#xxx"], port=>6697, host=>"irc.pirc.pl", real=>"xxx", id=>"xxx", secure=>true, catch_all=>true, user=>"xxx", get_stats=>true, enable_metric=>true, codec=><LogStash::Codecs::Plain id=>"xxx", enable_metric=>true, charset=>"UTF-8">, stats_interval=>5>
Dec 21 04:27:01 saya logstash[26428]:   Error: undefined method `force_encoding' for nil:NilClass
Dec 21 04:27:01 saya logstash[26428]:   Exception: NoMethodError
Dec 21 04:27:01 saya logstash[26428]:   Stack: /usr/share/logstash/logstash-core/lib/logstash/util/charset.rb:13:in `convert'
Dec 21 04:27:01 saya logstash[26428]: /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/logstash-codec-plain-3.0.6/lib/logstash/codecs/plain.rb:35:in `decode'
Dec 21 04:27:01 saya logstash[26428]: /usr/share/logstash/logstash-core/lib/logstash/codecs/delegator.rb:45:in `block in decode'
Dec 21 04:27:01 saya logstash[26428]: org/logstash/instrument/metrics/AbstractSimpleMetricExt.java:45:in `time'
Dec 21 04:27:01 saya logstash[26428]: org/logstash/instrument/metrics/AbstractNamespacedMetricExt.java:44:in `time'
Dec 21 04:27:01 saya logstash[26428]: /usr/share/logstash/logstash-core/lib/logstash/codecs/delegator.rb:44:in `decode'
Dec 21 04:27:01 saya logstash[26428]: /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/logstash-input-irc-3.0.7/lib/logstash/inputs/irc.rb:146:in `handle_response'
Dec 21 04:27:01 saya logstash[26428]: /usr/share/logstash/vendor/bundle/jruby/2.5.0/gems/logstash-input-irc-3.0.7/lib/logstash/inputs/irc.rb:117:in `run'
Dec 21 04:27:01 saya logstash[26428]: /usr/share/logstash/logstash-core/lib/logstash/java_pipeline.rb:322:in `inputworker'
Dec 21 04:27:01 saya logstash[26428]: /usr/share/logstash/logstash-core/lib/logstash/java_pipeline.rb:314:in `block in start_input'

• Steps to Reproduce:

1. Install plugin
2. Create new config inside /etc/logstash/conf.d/ directory
3. Start logstash
4. Leave for a moment on active channels

• Other info:
  Observed same situation as here https://discuss.elastic.co/t/logstash-irc-output-plugin-creates-new-irc-server-connections-on-reload/90293 after a while we have many stuck clients on channels.

[acidvegas]

The plugin seems to not be able to decode certain character sets on IRC. Ill see if I can get a PR to fix this soon.

This error is triggered because somewhere in the Logstash process, the program is trying to call the method force_encoding on an object that is nil. In Ruby, you can't call methods that are intended for a string on a nil value.

Looking at the stack trace, it appears that this error is originating from the IRC input plugin for Logstash. When the decode method is called in the plain codec, it appears to be passing a nil value, leading to the error.

[lenisko]

Nice to see some attention on 3-year-old issue ;-) thanks for great go through and good luck!