verse-otel

Vendor-neutral OpenTelemetry tracing for Verse services.

Out of the box you get spans for:

• every exposition invocation (HTTP endpoint or event subscriber), named MyExpo#action;
• the event bus — producer/consumer spans with trace context carried inside message headers, so a trace continues from the publishing service into every subscriber;
• whatever OTel instrumentations you enable — scoped to what the Verse stack runs on: rack/sinatra (verse-http), pg (verse-sequel), redis (verse-redis) and net_http (service-to-service calls).

No backend is hardwired. Standard OTEL_* environment variables configure exporters (OTEL_TRACES_EXPORTER=console for stdout debugging, or add opentelemetry-exporter-otlp and point OTEL_EXPORTER_OTLP_ENDPOINT at a collector/Tempo/Jaeger). Without an exporter, spans are dropped. For Sentry, use verse-sentry with tracing: otel.

Usage

# Gemfile
gem "verse-otel"

# Instrumentations are optional — add only the ones you enable in the config
# below. Booting with an instrumentation listed but its gem missing raises,
# with a message naming the gem to add.
gem "opentelemetry-instrumentation-rack"
gem "opentelemetry-instrumentation-sinatra"
gem "opentelemetry-instrumentation-net_http"
gem "opentelemetry-instrumentation-pg"
# gem "opentelemetry-instrumentation-redis"

redis is off by default on purpose: verse-otel already emits producer and consumer spans for the event bus, and the raw command spans underneath are dominated by the consumer's blocking XREADGROUP poll.

# config/config.yml
plugins:
  - plugin: otel
    config:
      enabled: true
      service_name_prefix: "myapp-"
      instrumentations: [rack, sinatra, net_http, pg]
      db_statement: obfuscate   # include | obfuscate | omit

Extension registry

Other plugins can contribute during their on_init; the registry is drained when this plugin's on_start configures the SDK, so declaration order does not matter:

Verse::Otel.add_span_processor(processor)  # extra span processors
Verse::Otel.propagator = propagator        # replace the propagator
Verse::Otel.untraced_hosts << "host"       # never trace calls to these hosts

Development

bundle install
bundle exec rspec