Docs incorrect! - Pipeline-to-Pipeline Communication not working - ConfigurationError

[nniikkoollaaii (nikolai)]

Hello,

I'm trying to get Pipeline-to-Pipeline Communication working according to the distributor pattern in https://www.elastic.co/guide/en/logstash/current/pipeline-to-pipeline.html#distributor-pattern

(I'm working on Kubernetes / Docker)

My Pipelines.yml:

- pipeline.id: input-pipeline
  path.config: "pipeline/input-pipeline.conf"
- pipeline.id: vtmd-pipeline
  path.config: "pipeline/vtmd-pipeline.conf"
[...]

My input-pipeline.conf:

input {
  beats {
    port => 5044
    host => "127.0.0.1"
    type => filebeat
  }

filter {
}

output {
  if [type] == "filebeat" {
    pipeline { send_to => vtmd-pipeline }
  }
[...]

My vtmd-pipeline.conf:

input { pipeline { address => vtmd-pipeline } }

filter {
}

output {
    elasticsearch {
      hosts => ["http://elasticsearch-logging:9200"]
      index => "%{[collector]}-%{[kubernetes][pod][name]}-%{+YYYY.MM.dd}"
  }
}

I cannot see any difference to the documentation mentioned above.

I'm using logstash version 6.3.2

The container fails to start with following logs:

Sending Logstash's logs to /usr/share/logstash/logs which is now configured via log4j2.properties
[2018-08-14T08:41:24,669][INFO ][logstash.setting.writabledirectory] Creating directory {:setting=>"path.queue", :path=>"/usr/share/logstash/data/queue"}
[2018-08-14T08:41:24,680][INFO ][logstash.setting.writabledirectory] Creating directory {:setting=>"path.dead_letter_queue", :path=>"/usr/share/logstash/data/dead_letter_queue"}
[2018-08-14T08:41:25,336][INFO ][logstash.agent           ] No persistent UUID file found. Generating new UUID {:uuid=>"82e73c15-ef1f-49fd-8744-72a433c04c87", :path=>"/usr/share/logstash/data/uuid"}
[2018-08-14T08:41:26,061][INFO ][logstash.runner          ] Starting Logstash {"logstash.version"=>"6.3.2"}
[2018-08-14T08:41:26,813][ERROR][logstash.agent           ] Failed to execute action {:action=>LogStash::PipelineAction::Create/pipeline_id:vtmd-pipeline, :exception=>"LogStash::ConfigurationError", :message=>"Expected one of #, { at line 1, column 45 (byte 45) after input { pipeline { address => vtmd-pipeline ", :backtrace=>["/usr/share/logstash/logstash-core/lib/logstash/compiler.rb:42:in `compile_imperative'", "/usr/share/logstash/logstash-core/lib/logstash/compiler.rb:50:in `compile_graph'", "/usr/share/logstash/logstash-core/lib/logstash/compiler.rb:12:in `block in compile_sources'", "org/jruby/RubyArray.java:2486:in `map'", "/usr/share/logstash/logstash-core/lib/logstash/compiler.rb:11:in `compile_sources'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:49:in `initialize'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:167:in `initialize'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline_action/create.rb:40:in `execute'", "/usr/share/logstash/logstash-core/lib/logstash/agent.rb:305:in `block in converge_state'"]}
[2018-08-14T08:41:27,343][ERROR][logstash.agent           ] Failed to execute action {:action=>LogStash::PipelineAction::Create/pipeline_id:input-pipeline, :exception=>"LogStash::ConfigurationError", :message=>"Expected one of #, { at line 29, column 41 (byte 387) after output {\n\n\n  #stdout { codec => rubydebug }\n\n  #fuer Input von filebeat\n  if [type] == \"filebeat\" {\n    pipeline { send_to => vtmd-pipeline ", :backtrace=>["/usr/share/logstash/logstash-core/lib/logstash/compiler.rb:42:in `compile_imperative'", "/usr/share/logstash/logstash-core/lib/logstash/compiler.rb:50:in `compile_graph'", "/usr/share/logstash/logstash-core/lib/logstash/compiler.rb:12:in `block in compile_sources'", "org/jruby/RubyArray.java:2486:in `map'", "/usr/share/logstash/logstash-core/lib/logstash/compiler.rb:11:in `compile_sources'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:49:in `initialize'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:167:in `initialize'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline_action/create.rb:40:in `execute'", "/usr/share/logstash/logstash-core/lib/logstash/agent.rb:305:in `block in converge_state'"]}
[2018-08-14T08:41:27,723][INFO ][logstash.agent           ] Successfully started Logstash API endpoint {:port=>9600}

(The line number isn't correct in my provided snippet because I skipped the kubernetes configmap overhead)

Why is Logstash expecting an "{" after the pipeline-address and not accepting the "}" to end this block?

[Badger]

@nniikkoollaaii

pipeline { send_to => vtmd-pipeline }

You made the mistake of relying on the documentation Try

    pipeline { send_to => "vtmd-pipeline" }

Similarly on the input

[nniikkoollaaii (nikolai)]

Thank you very much @Badger
That is the solution.

I change the titel, hoping that some elastic team member updates the documentation

[yaauie (Ry Biesemeyer)]

the docs are technically correct, but I see how a subtle change (adding a hyphen) can produce some hard-to-understand error messages. We should update the docs to just use quoted strings since it would be less likely to create this confusion.

Within the Logstash pipeline grammar, the ability to specify a string as an unquoted bareword (unquoted string) is limited to situations where the string contains only alphanumeric characters. In your case, the hyphen in the address name prevents the parser from recognising it as a bareword string, instead parsing it as the only other thing syntactically legal there, a codec definition.