Add DSM Integration to the Waterdrop instrumentation

[ericfirth]

This is one commit on top of the Waterdrop PR (here: #4874) to add DSM to the Waterdrop instrumentation

What does this PR do?

Motivation:

Change log entry

Additional Notes:

How to test the change?

[github-actions]

👋 Hey @DataDog/ruby-guild, please fill "Change log entry" section in the pull request description.

If changes need to be present in CHANGELOG.md you can state it this way

**Change log entry**

Yes. A brief summary to be placed into the CHANGELOG.md

(possible answers Yes/Yep/Yeah)

Or you can opt out like that

**Change log entry**

None.

(possible answers No/Nope/None)

^{Visited at: 2025-11-07 19:59:20 UTC}

[github-actions]

Typing analysis

Ignored files

This PR introduces 9 ignored files. It decreases the percentage of typed files from 36.87% to 36.49% (-0.38%).

Ignored files (+9-0)

❌ Introduced:

lib/datadog/tracing/contrib/karafka/framework.rb
lib/datadog/tracing/contrib/waterdrop.rb
lib/datadog/tracing/contrib/waterdrop/configuration/settings.rb
lib/datadog/tracing/contrib/waterdrop/distributed/propagation.rb
lib/datadog/tracing/contrib/waterdrop/ext.rb
lib/datadog/tracing/contrib/waterdrop/integration.rb
lib/datadog/tracing/contrib/waterdrop/middleware.rb
lib/datadog/tracing/contrib/waterdrop/patcher.rb
lib/datadog/tracing/contrib/waterdrop/producer.rb

[datadog-official]

✅ Tests

🎉 All green!

❄️ No new flaky tests detected
🧪 All tests passed

🎯 Code Coverage
• Patch Coverage: 96.52%
• Total Coverage: 98.54% (-0.03%)

View detailed report

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: dfadb4d | Docs | Datadog PR Page | Was this helpful? Give us feedback!}

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-11-10 20:05:58

Comparing candidate commit dfadb4d in PR branch eric.firth/add-waterdrop-dsm-integration with baseline commit c560834 in branch master.

Found 0 performance improvements and 1 performance regressions! Performance is the same for 43 metrics, 2 unstable metrics.

scenario:profiling - Allocations ()

• 🟥 throughput [-211347.299op/s; -202981.572op/s] or [-6.412%; -6.158%]