opentelemetry-exporter-otlp

opentelemetry-exporter-otlp

The opentelemetry-exporter-otlp gem provides an OTLP exporter for OpenTelemetry for Ruby. Using opentelemetry-exporter-otlp, an application can configure OpenTelemetry to export collected tracing data to the OpenTelemetry Collector.

What is OpenTelemetry?

OpenTelemetry is an open source observability framework, providing a general-purpose API, SDK, and related tools required for the instrumentation of cloud-native software, frameworks, and libraries.

OpenTelemetry provides a single set of APIs, libraries, agents, and collector services to capture distributed traces and metrics from your application. You can analyze them using Prometheus, Jaeger, and other observability tools.

How does this gem fit in?

The opentelemetry-exporter-otlp gem is a plugin that provides OTLP export. To export to the OpenTelemetry Collector, an application can include this gem along with opentelemetry-sdk, and configure the SDK to use the provided OTLP exporter as a span processor.

Generally, libraries that produce telemetry data should avoid depending directly on specific exporter, deferring that choice to the application developer.

Supported protocol version

This gem supports the v0.20.0 release of OTLP.

How do I get started?

Install the gem using:

gem install opentelemetry-sdk
gem install opentelemetry-exporter-otlp

Or, if you use bundler, include opentelemetry-sdk in your Gemfile.

Then, configure the SDK to use the OTLP exporter as a span processor, and use the OpenTelemetry interfaces to produces traces and other information. Following is a basic example.

require 'opentelemetry/sdk'
require 'opentelemetry/exporter/otlp'

# The OTLP exporter is the default, so no configuration is needed.
# However, it could be manually selected via an environment variable if required:
#
# ENV['OTEL_TRACES_EXPORTER'] = 'otlp'
#
# You may also configure various settings via environment variables:
# ENV['OTEL_EXPORTER_OTLP_COMPRESSION'] = 'gzip'

OpenTelemetry::SDK.configure

# To start a trace you need to get a Tracer from the TracerProvider
tracer_provider = OpenTelemetry.tracer_provider
tracer = tracer_provider.tracer('my_app_or_gem', '0.1.0')

# create a span
tracer.in_span('foo') do |span|
  # set an attribute
  span.set_attribute('platform', 'osx')
  # add an event
  span.add_event('event in bar')
  # create bar as child of foo
  tracer.in_span('bar') do |child_span|
    # inspect the span
    pp child_span
  end
end

tracer_provider.shutdown

For additional examples, see the examples on github.

How can I configure the OTLP exporter?

The collector exporter can be configured explicitly in code, or via environment variables as shown above. The configuration parameters, environment variables, and defaults are shown below.

Parameter	Environment variable	Default
endpoint:	OTEL_EXPORTER_OTLP_ENDPOINT	"http://localhost:4318/v1/traces"
certificate_file:	OTEL_EXPORTER_OTLP_CERTIFICATE
client_certificate_file	OTEL_EXPORTER_OTLP_CLIENT_CERTIFICATE
client_key_file	OTEL_EXPORTER_OTLP_CLIENT_KEY
headers:	OTEL_EXPORTER_OTLP_HEADERS
compression:	OTEL_EXPORTER_OTLP_COMPRESSION	"gzip"
timeout:	OTEL_EXPORTER_OTLP_TIMEOUT	10
ssl_verify_mode:	OTEL_RUBY_EXPORTER_OTLP_SSL_VERIFY_PEER or	OpenSSL::SSL:VERIFY_PEER
	OTEL_RUBY_EXPORTER_OTLP_SSL_VERIFY_NONE

ssl_verify_mode: parameter values should be flags for server certificate verification: OpenSSL::SSL:VERIFY_PEER and OpenSSL::SSL:VERIFY_NONE are acceptable. These values can also be set using the appropriately named environment variables as shown where VERIFY_PEER will take precedence over VERIFY_NONE. Please see the Net::HTTP docs for more information about these flags.

How can I get involved?

The opentelemetry-exporter-otlp gem source is on github, along with related gems including opentelemetry-sdk.

The OpenTelemetry Ruby gems are maintained by the OpenTelemetry-Ruby special interest group (SIG). You can get involved by joining us in GitHub Discussions or attending our weekly meeting. See the meeting calendar for dates and times. For more information on this and other language SIGs, see the OpenTelemetry community page.

License

The opentelemetry-exporter-otlp gem is distributed under the Apache 2.0 license. See LICENSE for more information.

Working with Proto Definitions

The OTel community maintains a repository with protobuf definitions that language and collector implementers use to generate code.

Maintainers are expected to keep up to date with the latest version of protos. This guide will provide you with step-by-step instructions on updating the OTLP Exporter gem with the latest definitions.

System Requirements

• git 2.41+
• protoc 22.5
• Ruby 3+

:warning: protoc 23.x changes the Ruby code generator to emit a serialized proto instead of a DSL. https://protobuf.dev/news/2023-04-20/. Please ensure you use protoc version 22.x in order to ensure we remain compatible with versions of protobuf prior to google-protobuf gem 3.18.

Upgrade Proto Definitions

Update the target otel-proto version in the Rakefile that matches a release tag in the proto repo, e.g.

  # Rakefile

  # https://github.com/open-telemetry/opentelemetry-proto/tree/v0.20.0
  PROTO_VERSION = `v0.20.0`

Generate the Ruby source files using rake:

$> bundle exec rake protobuf:generate

Run tests and fix any errors:

$> bundle exec rake test

Commit the changes and open a PR!