Add OpenTelemetry instrumentation (#30130)

Co-authored-by: Juliano Costa <juliano.costa@datadoghq.com>
Co-authored-by: Robb Kidd <robbkidd@honeycomb.io>

Gemfile

@@ -103,6 +103,24 @@ gem 'rdf-normalize', '~> 0.5'
 
 gem 'private_address_check', '~> 0.5'
 
+group :opentelemetry do
+  gem 'opentelemetry-exporter-otlp', '~> 0.26.3', require: false
+  gem 'opentelemetry-instrumentation-active_job', '~> 0.7.1', require: false
+  gem 'opentelemetry-instrumentation-active_model_serializers', '~> 0.20.1', require: false
+  gem 'opentelemetry-instrumentation-concurrent_ruby', '~> 0.21.2', require: false
+  gem 'opentelemetry-instrumentation-excon', '~> 0.22.0', require: false
+  gem 'opentelemetry-instrumentation-faraday', '~> 0.24.1', require: false
+  gem 'opentelemetry-instrumentation-http', '~> 0.23.2', require: false
+  gem 'opentelemetry-instrumentation-http_client', '~> 0.22.3', require: false
+  gem 'opentelemetry-instrumentation-net_http', '~> 0.22.4', require: false
+  gem 'opentelemetry-instrumentation-pg', '~> 0.27.1', require: false
+  gem 'opentelemetry-instrumentation-rack', '~> 0.24.1', require: false
+  gem 'opentelemetry-instrumentation-rails', '~> 0.30.0', require: false
+  gem 'opentelemetry-instrumentation-redis', '~> 0.25.3', require: false
+  gem 'opentelemetry-instrumentation-sidekiq', '~> 0.25.2', require: false
+  gem 'opentelemetry-sdk', '~> 1.4', require: false
+end
+
 group :test do
   # Adds RSpec Error/Warning annotations to GitHub PRs on the Files tab
   gem 'rspec-github', '~> 2.4', require: false

Gemfile.lock

@@ -284,6 +284,9 @@ GEM
       ruby-progressbar (~> 1.4)
     globalid (1.2.1)
       activesupport (>= 6.1)
+    google-protobuf (3.25.3)
+    googleapis-common-protos-types (1.14.0)
+      google-protobuf (~> 3.18)
     haml (6.3.0)
       temple (>= 0.8.2)
       thor
@@ -483,6 +486,96 @@ GEM
     openssl (3.2.0)
     openssl-signature_algorithm (1.3.0)
       openssl (> 2.0)
+    opentelemetry-api (1.2.5)
+    opentelemetry-common (0.20.1)
+      opentelemetry-api (~> 1.0)
+    opentelemetry-exporter-otlp (0.26.3)
+      google-protobuf (~> 3.14)
+      googleapis-common-protos-types (~> 1.3)
+      opentelemetry-api (~> 1.1)
+      opentelemetry-common (~> 0.20)
+      opentelemetry-sdk (~> 1.2)
+      opentelemetry-semantic_conventions
+    opentelemetry-helpers-sql-obfuscation (0.1.0)
+      opentelemetry-common (~> 0.20)
+    opentelemetry-instrumentation-action_pack (0.9.0)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+      opentelemetry-instrumentation-rack (~> 0.21)
+    opentelemetry-instrumentation-action_view (0.7.0)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-instrumentation-active_support (~> 0.1)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-active_job (0.7.1)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-active_model_serializers (0.20.1)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-active_record (0.7.1)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-active_support (0.5.1)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-base (0.22.3)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-registry (~> 0.1)
+    opentelemetry-instrumentation-concurrent_ruby (0.21.2)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-excon (0.22.0)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-common (~> 0.20.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-faraday (0.24.1)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-common (~> 0.20.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-http (0.23.2)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-http_client (0.22.3)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-common (~> 0.20.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-net_http (0.22.4)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-common (~> 0.20.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-pg (0.27.1)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-helpers-sql-obfuscation
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-rack (0.24.1)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-common (~> 0.20.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-rails (0.30.0)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-instrumentation-action_pack (~> 0.9.0)
+      opentelemetry-instrumentation-action_view (~> 0.7.0)
+      opentelemetry-instrumentation-active_job (~> 0.7.0)
+      opentelemetry-instrumentation-active_record (~> 0.7.0)
+      opentelemetry-instrumentation-active_support (~> 0.5.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-redis (0.25.3)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-common (~> 0.20.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-instrumentation-sidekiq (0.25.2)
+      opentelemetry-api (~> 1.0)
+      opentelemetry-common (~> 0.20.0)
+      opentelemetry-instrumentation-base (~> 0.22.1)
+    opentelemetry-registry (0.3.1)
+      opentelemetry-api (~> 1.1)
+    opentelemetry-sdk (1.4.1)
+      opentelemetry-api (~> 1.1)
+      opentelemetry-common (~> 0.20)
+      opentelemetry-registry (~> 0.2)
+      opentelemetry-semantic_conventions
+    opentelemetry-semantic_conventions (1.10.0)
+      opentelemetry-api (~> 1.0)
     orm_adapter (0.5.0)
     ox (2.14.18)
     parallel (1.24.0)
@@ -880,6 +973,21 @@ DEPENDENCIES
   omniauth-rails_csrf_protection (~> 1.0)
   omniauth-saml (~> 2.0)
   omniauth_openid_connect (~> 0.6.1)
+  opentelemetry-exporter-otlp (~> 0.26.3)
+  opentelemetry-instrumentation-active_job (~> 0.7.1)
+  opentelemetry-instrumentation-active_model_serializers (~> 0.20.1)
+  opentelemetry-instrumentation-concurrent_ruby (~> 0.21.2)
+  opentelemetry-instrumentation-excon (~> 0.22.0)
+  opentelemetry-instrumentation-faraday (~> 0.24.1)
+  opentelemetry-instrumentation-http (~> 0.23.2)
+  opentelemetry-instrumentation-http_client (~> 0.22.3)
+  opentelemetry-instrumentation-net_http (~> 0.22.4)
+  opentelemetry-instrumentation-pg (~> 0.27.1)
+  opentelemetry-instrumentation-rack (~> 0.24.1)
+  opentelemetry-instrumentation-rails (~> 0.30.0)
+  opentelemetry-instrumentation-redis (~> 0.25.3)
+  opentelemetry-instrumentation-sidekiq (~> 0.25.2)
+  opentelemetry-sdk (~> 1.4)
   ox (~> 2.14)
   parslet
   pg (~> 1.5)

config/initializers/opentelemetry.rb

@@ -0,0 +1,63 @@
+# frozen_string_literal: true
+
+# Set OTEL_* environment variables according to OTel docs:
+# https://opentelemetry.io/docs/concepts/sdk-configuration/
+
+if ENV.keys.any? { |name| name.match?(/OTEL_.*_ENDPOINT/) }
+  require 'opentelemetry/sdk'
+  require 'opentelemetry/exporter/otlp'
+
+  require 'opentelemetry/instrumentation/active_job'
+  require 'opentelemetry/instrumentation/active_model_serializers'
+  require 'opentelemetry/instrumentation/concurrent_ruby'
+  require 'opentelemetry/instrumentation/excon'
+  require 'opentelemetry/instrumentation/faraday'
+  require 'opentelemetry/instrumentation/http'
+  require 'opentelemetry/instrumentation/http_client'
+  require 'opentelemetry/instrumentation/net/http'
+  require 'opentelemetry/instrumentation/pg'
+  require 'opentelemetry/instrumentation/rack'
+  require 'opentelemetry/instrumentation/rails'
+  require 'opentelemetry/instrumentation/redis'
+  require 'opentelemetry/instrumentation/sidekiq'
+
+  OpenTelemetry::SDK.configure do |c|
+    # use_all() attempts to load ALL the auto-instrumentations
+    # currently loaded by Ruby requires.
+    #
+    # Load attempts will emit an INFO or WARN to the console
+    # about the success/failure to wire up an auto-instrumentation.
+    # "WARN -- : Instrumentation: <X> failed to install" is most
+    # likely caused by <X> not being a Ruby library loaded by
+    # the application or the instrumentation has been explicitly
+    # disabled.
+    #
+    # To disable an instrumentation, set an environment variable
+    # along this pattern:
+    #
+    # OTEL_RUBY_INSTRUMENTATION_<X>_ENABLED=false
+    #
+    # For example, PostgreSQL and Redis produce a lot of child spans
+    # in the course of this application doing its business. To turn
+    # them off, set the env vars below, but recognize that you will
+    # be missing details about what particular calls to the
+    # datastores are slow.
+    #
+    # OTEL_RUBY_INSTRUMENTATION_PG_ENABLED=false
+    # OTEL_RUBY_INSTRUMENTATION_REDIS_ENABLED=false
+
+    c.use_all({
+      'OpenTelemetry::Instrumentation::Rack' => {
+        use_rack_events: false, # instead of events, use middleware; allows for untraced_endpoints to ignore child spans
+        untraced_endpoints: ['/health'],
+      },
+    })
+
+    c.service_name =  case $PROGRAM_NAME
+                      when /puma/ then 'mastodon/web'
+                      else
+                        "mastodon/#{$PROGRAM_NAME.split('/').last}"
+                      end
+    c.service_version = Mastodon::Version.to_s
+  end
+end