Support OpenTelemetry via collector mode

.changesets/add-collector-attribute-options.md

@@ -0,0 +1,10 @@
+---
+bump: minor
+type: add
+---
+
+Add configuration options that map to OpenTelemetry resource attributes under collector mode: `service_name`, `filter_attributes`, `filter_function_parameters`, `filter_request_query_parameters`, `filter_request_payload`, `response_headers`, `send_function_parameters`, `send_request_query_parameters`, and `send_request_payload`. These tell the AppSignal Collector how to filter and forward telemetry data.
+
+When collector mode is active, existing configuration options (`name`, environment, `hostname`, `revision`, `ignore_actions`, `ignore_errors`, `ignore_namespaces`, `request_headers`, `filter_session_data`, `send_session_data`) are now passed to the collector as OpenTelemetry resource attributes.
+
+Setting any of these options without `collector_endpoint`, or `filter_parameters`/`filter_metadata`/`send_params` with `collector_endpoint`, now logs a warning at startup.

.changesets/add-collector-mode.md

@@ -0,0 +1,19 @@
+---
+bump: minor
+type: add
+---
+
+Add a new `collector_endpoint` configuration option (`APPSIGNAL_COLLECTOR_ENDPOINT` environment variable) that puts the integration in _collector mode_. When set, AppSignal additionally configures an OpenTelemetry SDK that exports OTLP/HTTP protobuf traces, metrics, and logs to the configured endpoint. The existing AppSignal agent continues to run unchanged; no AppSignal-collected data flows through the OpenTelemetry SDK yet.
+
+Collector mode requires Ruby 3.1 or newer and the OpenTelemetry gems, which are optional and not installed by default. To use it, add them to your application's `Gemfile`:
+
+```ruby
+gem "opentelemetry-sdk", ">= 1.8.0"
+gem "opentelemetry-metrics-sdk", ">= 0.7.1"
+gem "opentelemetry-logs-sdk", ">= 0.2.0"
+gem "opentelemetry-exporter-otlp", ">= 0.30.0"
+gem "opentelemetry-exporter-otlp-metrics", ">= 0.4.0"
+gem "opentelemetry-exporter-otlp-logs", ">= 0.2.0"
+```
+
+If these gems are missing or older than the minimum versions, AppSignal logs a warning and falls back to the bundled agent.

.changesets/add-faraday-integration.md

@@ -3,4 +3,4 @@ bump: minor
 type: add
 ---
 
-Improve Faraday support. AppSignal now instruments Faraday requests automatically, without double-instrumenting the underlying HTTP client. Turn it off with the `instrument_faraday` option.
+Improve Faraday support. AppSignal now instruments Faraday requests automatically, without double-instrumenting the underlying HTTP client, and, in collector mode, propagates trace context to the called service so it joins the same distributed trace. Turn it off with the `instrument_faraday` option.

.changesets/add-que-distributed-tracing.md

@@ -0,0 +1,6 @@
+---
+bump: minor
+type: add
+---
+
+Improve Que support. In collector mode, AppSignal now propagates trace context when enqueuing Que jobs, so each job links back to the trace that enqueued it. This covers single and bulk enqueues, on both Que 1 and Que 2.