Datadog APM Ruby integration test suite

Integration tests for datadog that use a variety of real applications.

Quickstart

1. Build Docker base images:

   ./script/build-images

You can specify which ruby version to build using the -v option.

2. Choose an application and follow instructions (in corresponding README.md.)

Demo applications

Ruby demo applications are configured with Datadog APM, which can be used to generate sample traces/profiles. These are used to drive tests in the integration suite.

Applications

See README.md in each directory for more information:

• apps/opentelemetry: Generates OpenTelemetry traces
• apps/rack: Rack application
• apps/rails-five: Rails 5 application
• apps/rails-six: Rails 6 application
• apps/rails-seven: Rails 7 application
• apps/rspec: RSpec test suite (CI)
• apps/ruby: Generic Ruby application
• apps/sinatra2-classic: Sinatra classic application
• apps/sinatra2-modular: Sinatra modular application

Base images

The images/ folders hosts some images for Ruby applications.

• datadog/dd-apm-demo:wrk / images/wrk/Dockerfile: wrk load testing application (for generating load)
• datadog/dd-apm-demo:agent / images/agent/Dockerfile: Datadog agent (with default configuration)
• datadog/dd-apm-demo:rb-<RUBY_VERSION> / images/<RUBY_VERSION>/Dockerfile: MRI Ruby & Datadog::DemoEnv (where <RUBY_VERSION> is minor version e.g. 2.7)

Ruby base images include Datadog::DemoEnv and other helpers.

Debugging

Profiling memory

Create a memory heap dump via:

# Profile for 5 minutes, dump heap to /data/app/ruby-heap.dump
# Where PID = process ID
bundle exec rbtrace -p PID -e 'Thread.new{GC.start; require "objspace"; ObjectSpace.trace_object_allocations_start; sleep(300); io=File.open("/data/app/ruby-heap.dump", "w"); ObjectSpace.dump_all(output: io); io.close}'

Then analyze it using analyzer.rb (built into the Ruby base images) with:

# Group objects by generation
ruby /vendor/dd-demo/datadog/analyzer.rb /data/app/ruby-heap.dump

# List objects in GEN_NUM, group by source location
ruby /vendor/dd-demo/datadog/analyzer.rb /data/app/ruby-heap.dump GEN_NUM

# List objects in all generations, group by source location, descending.
ruby /vendor/dd-demo/datadog/analyzer.rb /data/app/ruby-heap.dump objects

# List objects in all generations, group by source location, descending.
# Up to generation END_GEN.
ruby /vendor/dd-demo/datadog/analyzer.rb /data/app/ruby-heap.dump objects END_GEN

# List objects in all generations, group by source location, descending.
# Between generations START_GEN to END_GEN inclusive.
ruby /vendor/dd-demo/datadog/analyzer.rb /data/app/ruby-heap.dump objects END_GEN START_GEN