3.1.0.beta4 - Misleading error when SSL key or cert is not readable

[ceeeekay]

While running tests for elastic/logstash#5756 I noticed that if the SSL key or cert defined in the LS config are present but the logstash user cannot access them, LS throws a misleading error on startup.

An unexpected error occurred! {:error=>#<NoMethodError: undefined method stop' for nil:NilClass>, :backtrace=>["/usr/share/logstash/vendor/bundle/jruby/1.9/gems/logstash-input-beats-3.1.0.beta4-java/lib/logstash/inputs/beats.rb:173:in stop'", "/usr/share/logstash/logstash-core/lib/logstash/inputs/base.rb:88:indo_stop'", "org/jruby/RubyArray.java:1613:in each'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:366:inshutdown'", "/usr/share/logstash/logstash-core/lib/logstash/agent.rb:252:in stop_pipeline'", "/usr/share/logstash/logstash-core/lib/logstash/agent.rb:261:inshutdown_pipelines'", "org/jruby/RubyHash.java:1342:in each'", "/usr/share/logstash/logstash-core/lib/logstash/agent.rb:261:inshutdown_pipelines'", "/usr/share/logstash/logstash-core/lib/logstash/agent.rb:123:in shutdown'", "/usr/share/logstash/logstash-core/lib/logstash/runner.rb:237:inexecute'", "/usr/share/logstash/vendor/bundle/jruby/1.9/gems/clamp-0.6.5/lib/clamp/command.rb:67:in run'", "/usr/share/logstash/logstash-core/lib/logstash/runner.rb:157:inrun'", "/usr/share/logstash/vendor/bundle/jruby/1.9/gems/clamp-0.6.5/lib/clamp/command.rb:132:in run'", "/usr/share/logstash/lib/bootstrap/environment.rb:66:in`(root)'"], :level=>:fatal}

Ideally there should be a message stating "Key/cert cannot be read - check permissions" or similar.

Logstash 5.0.0-alpha5
logstash-input-beats 3.1.0.beta4
Ubuntu 14.04.5

[ph]

OK, this error need to be solved at the logstash level I will move the issue there.
Logstash doesn't check if he can read the file, we only verify if the file exist.

Logstash will show this error if the file doesn't exist.

Invalid setting for beats input plugin:

  input {
    beats {
      # This setting must be a path
      # File does not exist or cannot be opened /Users/ph/es/certificates/bad_certificates/certificate.wwwwcrt
      ssl_certificate => "/Users/ph/es/certificates/bad_certificates/certificate.wwwwcrt"
      ...
    }
  } {:level=>:error}
fetched an invalid config {:config=>"input {\n  beats {\n    port => 5044\n    ssl => true\n    ssl_certificate => \"/Users/ph/es/certificates/bad_certificates/certificate.wwwwcrt\"\n    ssl_key => \"/Users/ph/es/certificates/bad_certificates/certificate.key\"\n  }\n}\n\noutput {\n  stdout {\n    codec => dots\n  }\n}\n\n", :reason=>"Something is wrong with your configuration.", :level=>:error}
~/e/logstash git:remotes/upstream/2.4 ❯❯❯ bin/logstash -f ls_tools/beats.conf

[ph]

moved to elastic/logstash#5820