NullpointerException

[BrechtClaeys]

Hi,
When trying out one of the example configurations in the documentation, I keep getting errors. when running logstash.

This is the used configuration in my input:`

input{
  snmp {
    get => ["1.3.6.1.2.1.1.1.0"]
    hosts => [{host => "udp: 10.2.1.8/161" community => "public"}]
  }
}

I always get the following error:

[2019-01-28T10:50:52,026][ERROR][logstash.inputs.snmp     ] error invoking get operation on  10.2.1.7 for OIDs: ["1.3.6.1.2.1.1.1.0"], ignoring {:exception=>java.lang.NullPointerException, :backtrace=>["org.snmp4j.MessageDispatcherImpl.getTransport(org/snmp4j/MessageDispatcherImpl.java:225)", "org.snmp4j.MessageDispatcherImpl.sendPdu(org/snmp4j/MessageDispatcherImpl.java:446)", "org.snmp4j.Snmp.sendMessage(org/snmp4j/Snmp.java:1089)", "org.snmp4j.Snmp.send(org/snmp4j/Snmp.java:983)", "org.snmp4j.Snmp.send(org/snmp4j/Snmp.java:963)", "java.lang.reflect.Method.invoke(java/lang/reflect/Method.java:498)", "org.jruby.javasupport.JavaMethod.invokeDirectWithExceptionHandling(org/jruby/javasupport/JavaMethod.java:483)", "org.jruby.javasupport.JavaMethod.invokeDirect(org/jruby/javasupport/JavaMethod.java:338)", "usr.share.logstash.vendor.bundle.jruby.$2_dot_3_dot_0.gems.logstash_minus_input_minus_snmp_minus_1_dot_0_dot_1.lib.logstash.inputs.snmp.base_client.get(/usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-input-snmp-1.0.1/lib/logstash/inputs/snmp/base_client.rb:51)", "usr.share.logstash.vendor.bundle.jruby.$2_dot_3_dot_0.gems.logstash_minus_input_minus_snmp_minus_1_dot_0_dot_1.lib.logstash.inputs.snmp.block in run(/usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-input-snmp-1.0.1/lib/logstash/inputs/snmp.rb:160)", "org.jruby.RubyArray.each(org/jruby/RubyArray.java:1734)", "usr.share.logstash.vendor.bundle.jruby.$2_dot_3_dot_0.gems.logstash_minus_input_minus_snmp_minus_1_dot_0_dot_1.lib.logstash.inputs.snmp.run(/usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-input-snmp-1.0.1/lib/logstash/inputs/snmp.rb:156)", "usr.share.logstash.vendor.bundle.jruby.$2_dot_3_dot_0.gems.logstash_minus_input_minus_snmp_minus_1_dot_0_dot_1.lib.logstash.inputs.snmp.RUBY$method$run$0$__VARARGS__(usr/share/logstash/vendor/bundle/jruby/$2_dot_3_dot_0/gems/logstash_minus_input_minus_snmp_minus_1_dot_0_dot_1/lib/logstash/inputs//usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-input-snmp-1.0.1/lib/logstash/inputs/snmp.rb)", "usr.share.logstash.logstash_minus_core.lib.logstash.pipeline.inputworker(/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:409)", "usr.share.logstash.logstash_minus_core.lib.logstash.pipeline.RUBY$method$inputworker$0$__VARARGS__(usr/share/logstash/logstash_minus_core/lib/logstash//usr/share/logstash/logstash-core/lib/logstash/pipeline.rb)", "usr.share.logstash.logstash_minus_core.lib.logstash.pipeline.block in start_input(/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:403)", "org.jruby.RubyProc.call(org/jruby/RubyProc.java:289)", "org.jruby.RubyProc.call(org/jruby/RubyProc.java:246)", "java.lang.Thread.run(java/lang/Thread.java:748)"]}

Any idea what causes this?
Thanks in advance.

[axrayn]

Hi @BrechtClaeys

Looks like you have an extra space in the host address after the ":"
e.g. udp: 10.2.1.8/161 instead of udp:10.2.1.8/161

@colinsurprenant Looks like we may need to update the HOST_REGEX to raise a config error on whitespace or other invalid characters in the host address.

Something like: /^(?<host_protocol>udp|tcp):(?<host_address>[a-z\-\_\.\d]+)\/(?<host_port>\d+)$/i ?

[BrechtClaeys]

Oh wow, feeling kinda dumb now :)
Thanks for helping me out, would indeed be good to have a clearer error message there.

[colinsurprenant]

Thanks @BrechtClaeys @axrayn - yeah, not a great handling and error here.
I think we should just accept whitespaces to start with and yeah, make sure we don't trigger a NPE from invalid input :P