feat: add OTLP/JSON (http/json) export support by r-LaForge · Pull Request #2238 · open-telemetry/opentelemetry-ruby

r-LaForge · 2026-07-11T06:59:20Z

What type of PR is this?

/kind feature

What this PR does / why we need it:

implements the http/json export capability.

Which issue(s) this PR fixes:

Addresses #1874

Special notes for your reviewer:

The enums are exported as integers and the ids retain their hex encoding, as per the specification.

For retaining the hex values, I took inspiration from the PHP implementation, which also base64 decodes the ids before passing marshaling.
For the enum values, I bumped google-protobuf to 3.23.0. I felt this was the easiest way of meeting the specification without building a custom workaround.

There are some minor style changes to satisfy Rubocop.

Does this PR introduce a user-facing change?

FEATURE: Support for the http/json protocol has been added.
ACTION REQUIRED: The google-protobuf dependency has been updated to 3.23.0 from 3.18.0. Applications will need to update to >= 3.23.0.

Additional documentation:

- [SPEC]: See https://opentelemetry.io/docs/specs/otlp/#otlphttp-request
- [REFERENCE PR]: https://github.com/open-telemetry/opentelemetry-php/pull/973

The protocol defaults to http/protobuf, but can be set to http/json through the respective environment variables. Includes minor format adjustments to satisfy Rubocop rules

…liance - enums must be emitted as integers - Protobuf encodes strings as base64, but trace_ids and span_ids are hex Includes some minor changes to satisfy Rubocop

open-telemetry#1874

linux-foundation-easycla · 2026-07-11T06:59:25Z

The committers listed above are authorized under a signed CLA.

✅ login: r-LaForge / name: r-LaForge (9fd74ab, b2dbeae, fd7c898)

thompson-tomo · 2026-07-12T14:31:04Z

-            @uri = if endpoint == ENV['OTEL_EXPORTER_OTLP_ENDPOINT']
-                     endpoint += '/' unless endpoint.end_with?('/')
-                     URI.join(endpoint, 'v1/logs')
-                   else
-                     URI(endpoint)
-                   end
-
+            @uri = prepare_endpoint(endpoint)


Let's put this back. Note i have targeted pr to centralise the logic in common.

thompson-tomo · 2026-07-12T14:33:43Z

+        # As JSON etsr (ExportTraceServiceRequest)
+        #
+        # Serializes to spec-compliant OTLP/JSON: trace/span ids as hex strings and
+        # enum values as integers.
+        #
+        # @param [Enumerable<OpenTelemetry::SDK::Trace::SpanData>] span_data the
+        #   list of recorded {OpenTelemetry::SDK::Trace::SpanData} structs to be
+        #   encoded.
+        #
+        # @return [String] returns a JSON encoded ETSR of the provided span data
+        def as_json_etsr(span_data)
+          as_etsr(span_data, json: true).to_json(format_enums_as_integers: true)
+        rescue StandardError => e
+          OpenTelemetry.handle_error(exception: e, message: 'unexpected error in OTLP::Common#as_json_etsr')
+          nil
+        end
+


Can we consolidate this into the existing method with a new protocol parameter to control the difference.

thompson-tomo · 2026-07-12T14:37:51Z

-            send_bytes(OpenTelemetry::Exporter::OTLP::Common.as_encoded_etsr(span_data), timeout: timeout)
+            bytes = if @content_type == 'application/json'
+                      OpenTelemetry::Exporter::OTLP::Common.as_json_etsr(span_data)
+                    else
+                      OpenTelemetry::Exporter::OTLP::Common.as_encoded_etsr(span_data)
+                    end
+            send_bytes(bytes, timeout: timeout)


Update based on above

thompson-tomo · 2026-07-12T14:43:59Z

+            if @content_type == 'application/json'
+              as_export_logs_service_request(log_record_data, json: true).to_json(format_enums_as_integers: true)
+            else
+              Opentelemetry::Proto::Collector::Logs::V1::ExportLogsServiceRequest.encode(as_export_logs_service_request(log_record_data))
+            end


Suggested change

if @content_type == 'application/json'

as_export_logs_service_request(log_record_data, json: true).to_json(format_enums_as_integers: true)

else

Opentelemetry::Proto::Collector::Logs::V1::ExportLogsServiceRequest.encode(as_export_logs_service_request(log_record_data))

end

json = @content_type == 'application/json'

payload = as_export_logs_service_request(log_record_data, json: json)

if json

payload.to_json(format_enums_as_integers: true)

else

Opentelemetry::Proto::Collector::Logs::V1::ExportLogsServiceRequest.encode(payload)

end

thompson-tomo · 2026-07-12T14:45:45Z

-            @uri = if endpoint == ENV['OTEL_EXPORTER_OTLP_ENDPOINT']
-                     endpoint += '/' unless endpoint.end_with?('/')
-                     URI.join(endpoint, 'v1/metrics')
-                   else
-                     URI(endpoint)
-                   end
-
+            @uri = prepare_endpoint(endpoint)


thompson-tomo · 2026-07-12T14:46:50Z

+            if @content_type == 'application/json'
+              as_export_metrics_service_request(metrics_data, json: true).to_json(format_enums_as_integers: true)
+            else
+              Opentelemetry::Proto::Collector::Metrics::V1::ExportMetricsServiceRequest.encode(as_export_metrics_service_request(metrics_data))
+            end


Repeat previous pattern

thompson-tomo · 2026-07-12T14:47:54Z

+          def prepare_endpoint(endpoint)
+            return URI(endpoint) unless endpoint == ENV['OTEL_EXPORTER_OTLP_ENDPOINT']
+
+            endpoint += '/' unless endpoint.end_with?('/')
+            URI.join(endpoint, 'v1/metrics')
+          end


thompson-tomo · 2026-07-12T14:52:38Z

        # @return [Opentelemetry::Proto::Collector::Trace::V1::ExportTraceServiceRequest]
        #   returns an ETSR of the provided span data
-        def as_etsr(span_data)
+        def as_etsr(span_data, json: false)


Would it be better to avoid a mixture of named & positional arguments so something like

Suggested change

def as_etsr(span_data, json: false)

def as_etsr(span_data, json = false)

I really like your idea of using a positional argument here.
What do you think about the name format? (either :json or :protobuf); that term keeps the focus squarely on serialization and avoids any confusion with other terminology.

Also, what are your thoughts on making this a named argument for public methods, but keep it positional for private ones?

…protocol. - common.rb now accepts a `format` parameter that is either :json or :protobuf. - logs_exporter + metrics_exporter pass json as positional argument when converting to request. - trace_exporter derives format from the protocol. Thank you the feedback thompson-tomo open-telemetry#1874

r-LaForge added 3 commits July 10, 2026 22:31

feat: add http/json support to exporters

fd7c898

The protocol defaults to http/protobuf, but can be set to http/json through the respective environment variables. Includes minor format adjustments to satisfy Rubocop rules

feat: Include otlp-http and otlp-common and adjust JSON for spec comp…

9fd74ab

…liance - enums must be emitted as integers - Protobuf encodes strings as base64, but trace_ids and span_ids are hex Includes some minor changes to satisfy Rubocop

feat: Update READMEs and protobuf dep in gemspec

b2dbeae

open-telemetry#1874

r-LaForge changed the title ~~WIP: OTLP Exporter: allow json export~~ OTLP Exporter: allow json export Jul 11, 2026

r-LaForge changed the title ~~OTLP Exporter: allow json export~~ feat: add OTLP/JSON (http/json) export support Jul 11, 2026

r-LaForge marked this pull request as ready for review July 11, 2026 20:27

r-LaForge requested review from a team, dazuma, fbogsany, kaylareopelle, mwear, robbkidd, robertlaurin and xuan-cao-swi as code owners July 11, 2026 20:27

thompson-tomo reviewed Jul 12, 2026

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r-LaForge requested a review from thompson-tomo July 14, 2026 04:13

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feat: add OTLP/JSON (http/json) export support#2238

feat: add OTLP/JSON (http/json) export support#2238
r-LaForge wants to merge 4 commits into
open-telemetry:mainfrom
r-LaForge:allow-json-export

r-LaForge commented Jul 11, 2026 •

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-            if @content_type == 'application/json'
-              as_export_logs_service_request(log_record_data, json: true).to_json(format_enums_as_integers: true)
-            else
-              Opentelemetry::Proto::Collector::Logs::V1::ExportLogsServiceRequest.encode(as_export_logs_service_request(log_record_data))
-            end
+            json = @content_type == 'application/json'
+            payload = as_export_logs_service_request(log_record_data, json: json)
+            if json
+              payload.to_json(format_enums_as_integers: true)
+            else
+              Opentelemetry::Proto::Collector::Logs::V1::ExportLogsServiceRequest.encode(payload)
+            end

	def as_etsr(span_data, json: false)
	def as_etsr(span_data, json = false)

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Does this PR introduce a user-facing change?

Additional documentation:

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r-LaForge commented Jul 11, 2026 •

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