[mmahacek]

Updated the format for custom headers in documentation as the previous example would cause a pipeline error and Logstash would fail to start.

[mmahacek]

Fixes #158

[Copilot]

🟡 Changes recommended

The documented headers example uses an unsupported array of hashes, and the type descriptions should identify the supported single-hash format.

1 open issue

• Declare HTTP headers as a hash, not an array of hashes · New

What changed in this PR

This documentation-only PR revises the Logstash HTTP output plugin’s custom-header guidance to address reported pipeline startup failures.

Changes:

• Changes the documented headers type from a hash to a list of hashes.
• Replaces the custom-header example with an array containing two header hashes.

File	Description
docs/​index.asciidoc	Updates the headers type descriptions and configuration example.

_{Review effort: Balanced}

[donoghuc]

headers =>	Result
["X-My-Header", "%{host}"] (current docs)	works
{ "X-My-Header" => "%{host}" }	works
{ "X-A" => "1" "X-B" => "2" }	works
{ "X-A" => "1", "X-B" => "2" }	fails at startup (parse error, commas not allowed)
[{"X-My-Header" => "%{host}"}]	fails at startup (must contain an even number of items)
[{"X-My-Header" => "%{host}"}, {"X-My-Header2" => "value"}] (this PR)	starts, then drops every event

Could you share the config and error that made Logstash fail to start? I'd like to confirm it was one of the two startup failures above.

Suggestion: keep the type as hash and use the same format as other plugins (e.g. custom_headers in the elasticsearch output):

| <<plugins-{type}s-{plugin}-headers>> |<<hash,hash>>|No

===== `headers`

  * Value type is <<hash,hash>>
  * There is no default value for this setting.

Custom headers to send with each request, as a hash of `"Header-Name" => "value"` pairs.
Values support field references.

[source,ruby]
    headers => {
      "X-My-Header" => "%{[host][name]}"
      "X-Other"     => "static-value"
    }

Separate entries with spaces or newlines, not commas.

The same example should go in the comment at lib/logstash/outputs/http.rb:53.

[mmahacek]

Unfortunately, I don't have the original config from when I raised this last year. I also did some testing, and matched your results. I pushed updates to update the documentation to match line 3 from your tests, showing multiple headers, and also updated the comment in http.rb.